Swim Speed and Menstrual Cycle

I have heard many women complain about a general slowdown, a mental sluggishness as well as
physical. I'm the only one I've ever known who was distinctly more revved up beginning 4 to 5 before
menstruation. This was so dependable that if I had a major project that required my best energy,
that was the best time to begin. After each period was an equally dependable slump. I should add
that I'm generally inclined to be rather high all the time and my slump pace is still a sprint. I
would have thought that a rise or dip in estrogen and progesterone levels would effect all women
similarly, but from my anecdote of one that seems not to be the case.

Ruth Kazez

MSEagan said:

OK. I have noticed this pattern for a long time now and would like to know if there is a
physiological explanation for my consistent slow down that seems to happen every month just about
4-5 days before the beginning of menstration. Even if I have no noticeable symptoms (e.g. cramps),
I get slower, only to speed up again after about day 3 from the onset of menstruation. I have
wondered if it is psychological, but many times I forget my dates and when I question why I am
slower, I suddenly remember the time of month.

Marianne

There have been many studies performed trying to relate female athletic performance to phases of the
menstrual cycle. The conclusions have been that there are no consistent and clear-cut relationships.
I'll post a bibliography of these studies in the next day or so.

Plus, it's politically incorrect to even hint at the existence of such a relationship. Shame
on you guys.

- Larry W

This was an absolutely fantastic question as far as i am concerned (as both a coach and a
physiologist), and i think i found the answer to your question. Orginially, i thought of hormonal
fluctuation, but wasn't sure how much that would effect physical performance to such a noticeable
degree, doing some reading, i found the following:

The bottom line is that during the period you discuss, the luteal phase, the sweating response
occurs at a higher temperature than normal (the follicular phase). This means that heat cannot be
dissipated as normal, and the core temperature escalation leads to heat stress. The impairment of
performance was found while working at both 60% of VO2Max, and at 80% VO2Max, which generally is
where most swimming training takes place.

So lets take a field example of training for a marathon in july....essentially, for those few days
of the cycle, its similar to running at say 1pm in the afternoon, vs training at 5pm the rest of
the month.

Hope that cleared it up for you, and thanks for asking it! 🙂

steve

"MSEagan" <[email hidden]> wrote in message news:SJxpb.70554$mZ5.437264@attbi_s54...

Quoted message said:

OK. I have noticed this pattern for a long time now and would like to know if there is a
physiological explanation for my consistent slow down that seems to happen every month just about
4-5 days before the beginning of menstration. Even if I have no noticeable symptoms (e.g. cramps),
I get slower, only to speed up again after about day 3 from the onset of menstruation. I have
wondered if it is psychological, but many times I forget my dates and when I question why I am
slower, I suddenly remember

the

Quoted message said:

time of month.

Marianne

Thanks for this information--very interesting. But would this apply if one is actually continuously
cold while swimming, as is my case at the Purdue University pool ? In fact, if I could swim a little
faster, like I seem to do at other times of the month, I can usually put myself just above this
chill threshold because I can go faster.

Although this may be a "politically incorrect" question....the facts are that men and women are
physically different (and wouldn't it be a boring world for many of us if we were not?)

Marianne

"diablo" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

This was an absolutely fantastic question as far as i am concerned (as

both

Quoted message said:

a coach and a physiologist), and i think i found the answer to your question. Orginially, i
thought of hormonal fluctuation, but wasn't sure

how

Quoted message said:

much that would effect physical performance to such a noticeable degree, doing some reading, i
found the following:

The bottom line is that during the period you discuss, the luteal phase,

the

Quoted message said:

sweating response occurs at a higher temperature than normal (the

follicular

Quoted message said:

phase). This means that heat cannot be dissipated as normal, and the core temperature escalation
leads to heat stress. The impairment of performance was found while working at both 60% of VO2Max,
and at 80% VO2Max, which generally is where most swimming training takes place.

So lets take a field example of training for a marathon in july....essentially, for those few days
of the cycle, its similar to

running

Quoted message said:

at say 1pm in the afternoon, vs training at 5pm the rest of the month.

Hope that cleared it up for you, and thanks for asking it! 🙂

steve

"MSEagan" <[email hidden]> wrote in message news:SJxpb.70554$mZ5.437264@attbi_s54...

Quoted message said:

OK. I have noticed this pattern for a long time now and would like to

know

Quoted message said:

Quoted message said:

if there is a physiological explanation for my consistent slow down that seems to happen every
month just about 4-5 days before the beginning of menstration. Even if I have no noticeable
symptoms (e.g. cramps), I get slower, only to speed up again after about day 3 from the onset of
menstruation. I have wondered if it is psychological, but many times I forget my dates and when
I question why I am slower, I suddenly remember

the

Quoted message said:

time of month.

Marianne

This is an odd turn up. If your core temperature is above what it is during the regular cycle, you
should feel "hot". I'm only taking a guess at this part, but sometimes, what you perceive and what
is actually happening in terms of thermoregulation are not always related - take a fever for
example. i would venture to guess its a diluted effect such as that. As for the pool being cold, it
may feel cold to you, but its still like exercising in warm air.

"MSEagan" <[email hidden]> wrote in message news:bQzpb.74408$9E1.331939@attbi_s52...

Quoted message said:

Thanks for this information--very interesting. But would this apply if one is actually
continuously cold while swimming, as is my case at the Purdue University pool ? In fact, if I
could swim a little faster, like I seem to do at other times of the month, I can usually put
myself just above this chill threshold because I can go faster.

Although this may be a "politically incorrect" question....the facts are that men and women are
physically different (and wouldn't it be a boring world for many of us if we were not?)

Marianne

"diablo" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

This was an absolutely fantastic question as far as i am concerned (as

both

Quoted message said:

a coach and a physiologist), and i think i found the answer to your question. Orginially, i
thought of hormonal fluctuation, but wasn't sure

how

Quoted message said:

much that would effect physical performance to such a noticeable degree, doing some reading, i
found the following:

The bottom line is that during the period you discuss, the luteal phase,

the

Quoted message said:

sweating response occurs at a higher temperature than normal (the

follicular

Quoted message said:

phase). This means that heat cannot be dissipated as normal, and the

core

Quoted message said:

Quoted message said:

temperature escalation leads to heat stress. The impairment of

performance

Quoted message said:

Quoted message said:

was found while working at both 60% of VO2Max, and at 80% VO2Max, which generally is where most
swimming training takes place.

So lets take a field example of training for a marathon in july....essentially, for those few
days of the cycle, its similar to

running

Quoted message said:

at say 1pm in the afternoon, vs training at 5pm the rest of the month.

Hope that cleared it up for you, and thanks for asking it! 🙂

steve

"MSEagan" <[email hidden]> wrote in message news:SJxpb.70554$mZ5.437264@attbi_s54...

Quoted message said:

OK. I have noticed this pattern for a long time now and would like to

know

Quoted message said:

Quoted message said:

if there is a physiological explanation for my consistent slow down

that

Quoted message said:

Quoted message said:

Quoted message said:

seems to happen every month just about 4-5 days before the beginning

of

Quoted message said:

Quoted message said:

Quoted message said:

menstration. Even if I have no noticeable symptoms (e.g. cramps), I

get

Quoted message said:

Quoted message said:

Quoted message said:

slower, only to speed up again after about day 3 from the onset of menstruation. I have
wondered if it is psychological, but many times I forget my dates and when I question why I am
slower, I suddenly

remember

Quoted message said:

Quoted message said:

the

Quoted message said:

time of month.

Marianne

The Menstrual Cycle and Exercise Performance

1: Sports Med. 2003;33(11):833-51.

Effects of the menstrual cycle on exercise performance.

Janse de Jonge XA.

School of Exercise and Sport Science, Faculty of Health Sciences, The University of Sydney, Sydney,
New South Wales, Australia.
[email hidden]

This article reviews the potential effects of the female steroid hormone fluctuations during the
menstrual cycle on exercise performance. The measurement of estrogen and progesterone concentration
to verify menstrual cycle phase is a major consideration in this review. However, even when hormone
concentrations are measured, the combination of differences in timing of testing, the high inter-
and intra-individual variability in estrogen and progesterone concentration, the pulsatile nature of
their secretion and their interaction, may easily obscure possible effects of the menstrual cycle on
exercise performance. When focusing on studies using hormone verification and electrical stimulation
to ensure maximal neural activation, the current literature suggests that fluctuations in female
reproductive hormones throughout the menstrual cycle do not affect muscle contractile
characteristics. Most research also reports no changes over the menstrual cycle for the many
determinants of maximal oxygen consumption (VO2max), such as lactate response to exercise,
bodyweight, plasma volume, haemoglobin concentration, heart rate and ventilation. Therefore, it is
not surprising that the current literature indicates that VO2max is not affected by the menstrual
cycle. These findings suggest that regularly menstruating female athletes, competing in
strength-specific sports and intense anaerobic/aerobic sports, do not need to adjust for menstrual
cycle phase to maximise performance. For prolonged exercise performance, however, the menstrual
cycle may have an effect. Even though most research suggests that oxygen consumption, heart rate and
rating of perceived exertion responses to sub-maximal steady-state exercise are not affected by the
menstrual cycle, several studies report a higher cardiovascular strain during moderate exercise in
the mid-luteal phase. Nevertheless, time to exhaustion at sub-maximal exercise intensities shows no
change over the menstrual cycle. The significance of this finding should be questioned due to the
low reproducibility of the time to exhaustion test. During prolonged exercise in hot conditions, a
decrease in exercise time to exhaustion is shown during the mid-luteal phase, when body temperature
is elevated. Thus, the mid-luteal phase has a potential negative effect on prolonged exercise
performance through elevated body temperature and potentially increased cardiovascular strain.
Practical implications for female endurance athletes may be the adjustment of competition schedules
to their menstrual cycle, especially in hot, humid conditions. The small scope of the current
research and its methodological limitations warrant further investigation of the effect of the
menstrual cycle on prolonged exercise performance.

2: Sports Med. 2002;32(10):601-14.

Physiological responses to the menstrual cycle: implications for the development of heat illness in
female athletes.

Marsh SA, Jenkins DG.

School of Human Movement Studies, University of Queensland, Brisbane, Australia.
[email hidden]

Fluctuations in estrogen and progesterone during the menstrual cycle can cause changes in body
systems other than the reproductive system. For example, progesterone is involved in the regulation
of fluid balance in the renal tubules and innervation of the diaphragm via the phrenic nerve.
However, few significant changes in the responses of the cardiovascular and respiratory systems,
blood lactate, bodyweight, performance and ratings of perceived exertion are evident across the
cycle. Nevertheless, substantial evidence exists to suggest that increased progesterone levels
during the luteal phase cause increases in both core and skin temperatures and alter the temperature
at which sweating begins during exposure to both ambient and hot environments. As heat illness is
characterised by a significant increase in body temperature, it is feasible that an additional
increase in core temperature during the luteal phase could place females at an increased risk of
developing heat illness during this time. In addition, it is often argued that physiological gender
differences such as oxygen consumption, percentage body fat and surface area-to-mass ratio place
females at a higher risk of heat illness than males. This review examines various physiological
responses to heat exposure during the menstrual cycle at rest and during exercise, and considers
whether such changes increase the risk of heat illness in female athletes during a particular phase
of the menstrual cycle.

3: Curr Womens Health Rep. 2001 Dec;1(3):232-40.

Relationship between athletic performance and menstrual cycle.

Lebrun CM, Rumball JS.

Primary Care Sport Medicine and Research, Fowler Kennedy Sport Medicine Clinic, University of
Western Ontario, London, Ontario N6A 3K7, Canada. [email hidden]

actions on body systems other than the reproductive axis. Female athletes, coaches, medical
professionals, and researchers have long been concerned about the potential impact of menstrual
cycle fluctuations in these hormones on components of athletic performance. Estrogen is known to
affect the cardiovascular system, bone, and the brain; progesterone primarily influences
thermoregulation and ventilation. Substrate metabolism is likely altered by both hormones. Net
physiological effects can be either opposing or synergistic and are determined by the relative
proportions of each. Nevertheless, investigations to date have not consistently demonstrated
significant differences in aerobic capacity, anaerobic capacity, aerobic endurance, or muscle
strength in any specific menstrual cycle phase. The course of some chronic diseases may vary
slightly during the menstrual cycle, but the mechanism is currently unknown. Recent research in
underlying hormonal causes for anterior cruciate ligament (ACL) injuries also is not convincing.

4: Int J Sport Nutr Exerc Metab. 2001 Dec;11(4):430-41.

Carbohydrate-loading during the follicular phase of the menstrual cycle: effects on muscle glycogen
and exercise performance.

Paul DR, Mulroy SM, Horner JA, Jacobs KA, Lamb DR.

Diet and Human Performance Laboratory at the Beltsville Human Nutrition Research Center, ARS, USDA,
MD 20705, USA.

The effects of employing a high-carbohydrate diet (carbohydrate-loading) to increase glycogen
storage in skeletal muscle are not well established in female athletes. On 4 occasions--2
familiarization trials and 2 experimental trials--6 well-trained female subjects completed 6 x
15-min continuous intervals of cycling (12 min at 72% VO2max, 1 min at maximal effort, and 2 min at
50% VO2max), followed by a time trial 15 min later. The women consumed their habitual diets (HD; 6-7
g carbohydrate/kg lean body mass) for 3 days after the second familiarization trial and before the
first experimental trial. During the 3 days following the first experimental trial, the subjects
consumed a high-carbohydrate diet (CD; 9-10 g carbohydrate/kg lean body mass) prior to the second
experimental trial. Mean (+/-SEM) pre-exercise muscle glycogen concentrations were greater after CD
versus HD (171.9+/-8.7 vs.
5.4+/-10.3 mmol/kg wet weight, P < 0.003). Although 4 of the 6 subjects improved their time-trial
performance after CD, mean performance for the time trial was not significantly different between
diets (HD: 763.9+/-35.6 s; CD:
6.9+/-30.1 s). Thus, female cyclists can increase their muscle glycogen stores after a
carbohydrate-loading diet during the follicular phase of the menstrual cycle, but we found no
compelling evidence of a dietary effect on performance of a cycling time trial performed after 90
min of moderate-intensity exercise.

7: J Exp Biol. 2002 Jan;205(Pt 2):233-9.

Effect of menstrual cycle phase on exercise performance of high-altitude native women at 3600
m.

Brutsaert TD, Spielvogel H, Caceres E, Araoz M, Chatterton RT, Vitzthum VJ.

Department of Anthropology, The University at Albany, State University of New York, 12222, USA.
[email hidden]

At sea level normally menstruating women show increased ventilation (VE) and hemodynamic changes due
to increased progesterone (P) and estrogen
(E2) levels during the mid-luteal (L) compared to the mid-follicular (F) phase of the ovarian cycle.
Such changes may affect maximal exercise performance. This repeated-measures, randomized study,
conducted at 3600 m, tests the hypothesis that a P-mediated increase in VE increases maximal
oxygen consumption (V(O(2)max)) during the L phase relative to the F phase in Bolivian women,
either born and raised at high altitude (HA), or resident at HA since early childhood. Subjects
(N=30) enrolled in the study were aged 27.7 +/- 0.7 years (mean +/- S.E.M.) and non-pregnant,
non-lactating, relatively sedentary residents of La Paz, Bolivia, who were not using hormonal
contraceptives. Mean salivary P levels at the time of the exercise tests were 63.3 pg ml(-1)
and 22.9 pg ml(-1) for the L and F phases, respectively. Subset analyses of submaximal (N=23)
and maximal (N=13) exercise responses were conducted only with women showing increased P levels
from F to L and, in the latter case, with those also achieving true (V(O(2)max)). Submaximal
exercise VE and ventilatory equivalents were higher in the L phase (P<0.001). P levels were
significantly correlated to the submaximal exercise VE (r=0.487, P=0.006). Maximal work output
(W) was higher (approximately 5 %) during the L phase (P=0.044), but (V(O(2)max)) (l min(-1))
was unchanged (P=0.063). Post-hoc analyses revealed no significant relationship between changes
in P levels and changes in
(V(O(2)max))) from F to L (P=0.072). In sum, the menstrual cycle phase has relatively modest effects
on ventilation, but no effect on
(V(O(3)max)) of HA native women.

6: Am J Physiol Endocrinol Metab. 2001 Oct;281(4):E817-25.

Glucose kinetics and exercise performance during phases of the menstrual cycle: effect of glucose
ingestion.

Campbell SE, Angus DJ, Febbraio MA.

Exercise Physiology and Metabolism Laboratory, Department of Physiology, The University of
Melbourne, Parkville, Victoria 3010, Australia.

To study the effect of menstrual cycle phase and carbohydrate ingestion on glucose kinetics and
exercise performance, eight healthy, moderately trained, eumenorrheic women cycled at 70% of peak
O(2) consumption for 2 h and then performed a 4 kJ/kg body wt time trial. A control (C) and a
glucose ingestion (G) trial were completed during the follicular (F) and luteal (L) phases of
the menstrual cycle. Plasma substrate concentrations were similar before the commencement of
exercise. Glucose rates of appearance and disappearance were higher (P < 0.05) during the 2nd h
of exercise in FC than in LC. The percent contribution of carbohydrate to total energy
expenditure was greater in FC than in LC, and subjects performed better (13%, P < 0.05) in FC.
Performance improved (19% and 26% in FG and LG compared with FC and LC, respectively, P < 0.05)
with the ingestion of glucose throughout exercise. These data demonstrate that substrate
metabolism and exercise performance are influenced by the menstrual cycle phase, but ingestion
of glucose minimizes these effects.

7: Med Sci Sports Exerc. 2000 Feb;32(2):486-92.

Influence of the menstrual cycle phase and menstrual symptoms on maximal anaerobic performance.

Giacomoni M, Bernard T, Gavarry O, Altare S, Falgairette G.

Unite d'Ergonomie Sportive et Performance, U.F.R.
S.T.A.P.S, Universite de Toulon et du Var, France.

PURPOSE: This study was designed to analyze the effect of the menstrual cycle phase on maximal
anaerobic performance during short-term anaerobic tests. METHODS: Seven eumenorrheic women (NOC) and
10 women using monophasic oral contraceptives (OC) performed three anaerobic tests (force-velocity,
multi-jump, and squatting jump tests) during menstruation (M: between days 1 and 4), the
midfollicular phase (F: between days 7 and 9), and the midluteal phase (L: between days 19 and 21)
of the ovarian cycle. Follicular and luteal phases were confirmed by serum progesterone levels. The
order of testing sessions was randomly assigned and a 15-min standardized warm-up preceded each
testing session. Rectal temperatures were taken before (Trec(b)) and after (Trec(a)) warm-up.
RESULTS: No significant differences were observed among M, F, and L in Trec(b), Trec(a) maximal
cycling power (Pmax(c)), maximal jumping power (Pmax(j)), or maximal height of jump (h(j)) in either
NOC or OC. Ten of the women suffered premenstrual or menstrual symptoms (MS); the other seven did
not report any premenstrual or menstrual discomfort (NMS). Presence or absence of symptoms was not
correlated with oral contraceptive use. No significant differences were observed among the three
stages of the menstrual cycle in Pmax(c), Pmax(j), or h(j) in NMS. In MS, only Pmax(j) decreased by
8% in M compared with that in F (P < .05). CONCLUSIONS: Although there were no significant
differences in maximal anaerobic performance during different menstrual cycle phases, results of
this study suggest that the presence or absence of premenstrual or menstrual syndrome symptoms may
have an effect, possibly through an action on the stretch-shortening cycle of tendons and ligaments.

8: Can J Appl Physiol. 2000 Feb;25(1):35-54.

Exercise and training in women, Part II: Influence of menstrual cycle and pregnancy.

Shephard RJ.

Physical Education & Health, Department of Public Health Sciences, University of Toronto, P. O. Box
521 Brackendale, BC V0N 1H0.

This part of the review considers the impact of the menstrual cycle and pregnancy upon exercise
performance, together with the implications of continued, regular exercise for the developing
foetus. Specific issues that are covered include changes in physical performance over the
menstrual cycle; the impact of training on the menstrual cycle; a need for awareness of potential
pregnancy; alterations in fitness, performance, circulatory, respiratory and metabolic function
during pregnancy; potential hazards to the foetus from hyperthermia and hypoxia; a recommended
physical activity programme for the pregnant woman; and the impact of continued exercise upon
pregnancy outcomes.

9: J Appl Physiol. 2000 Feb;88(2):690-7.

Effect of menstrual cycle phase on carbohydrate supplementation during prolonged exercise
to fatigue.

Bailey SP, Zacher CM, Mittleman KD.

Department of Physical Therapy Education, Elon College, Elon College, North Carolina 27244, USA.
[email hidden]

The effects of menstrual cycle phase and carbohydrate (CHO) supplementation were investigated during
prolonged exercise. Nine healthy, moderately trained women cycled at 70% peak O(2) consumption until
exhaustion. Two trials were completed during the follicular (Fol) and luteal (Lut) phases of the
menstrual cycle. Subjects consumed 0.6 g CHO. kg body wt(-1). h(-1) (5 ml/kg of a 6% CHO solution
every 30 min beginning at min 30 of exercise) or a placebo drink (Pl) during exercise. Time to
exhaustion during CHO increased from Pl values (P < 0.05) by
10.4 +/- 8.5 (Fol) and 11.4 +/- 7.1% (Lut); no differences were observed between menstrual cycle
phases. CHO attenuated (P < 0.05) the decrease in plasma glucose and insulin and the increase
in plasma free fatty acids, tryptophan, epinephrine, and cortisol observed during Pl for both
phases. Plasma alanine, glutamine, proline, and isoleucine were lower (P < 0.05) in Lut than
in Fol phase. CHO resulted in lower (P < 0.05) plasma tyrosine, valine, leucine, isoleucine,
and phenylalanine. These results indicate that the menstrual cycle phase does not alter the
effects of CHO supplementation on performance and plasma levels of related substrates during
prolonged exercise.

11: Eur J Appl Physiol Occup Physiol. 1999 Jul;80(2):76-83.

Influence of menstrual cycle and oral contraceptives on tolerance to uncompensable heat stress.

Tenaglia SA, McLellan TM, Klentrou PP.

Defence and Civil Institute of Environmental Medicine, Human Protection and Performance Section,
North York, ON, Canada.

In this study we examined the influence of menstrual cycle phase and oral contraceptive use on
thermoregulation and tolerance during uncompensable heat stress. Eighteen women (18-35 years), who
differed only with respect to oral contraceptive use (n = 9) or non-use (n = 9), performed light
intermittent exercise at 40 degrees C and 30% relative humidity while wearing nuclear, biological
and chemical protective clothing. Their responses were compared during the early follicular (EF,
days 2-5) and mid-luteal (ML, days 19-22) phases of the menstrual cycle. Since oral contraceptives
are presumed to inhibit ovulation, a quasi-early follicular (q-EF) and quasi-mid-luteal (q-ML) phase
was assumed for the users. Estradiol and progesterone measurements verified that all subjects were
tested during the desired phases of the menstrual cycle. Results demonstrated that rectal
temperature (Tre) was elevated in ML compared with EF among the non-users at the beginning and
throughout the heat-stress trial. For the users, Tre was higher in q-ML compared with q-EF at the
beginning, and for 75 min of the heat-stress exposure. Tolerance times were significantly longer
during EF [128.1
(11.1) min, mean (SD)] compared with ML [107.4
(11.2) min] for the nonusers, indicating that these women are at a thermoregulatory advantage during
the EF phase of their menstrual cycle. For the users, tolerance times were similar in both
the q-EF [113.0 (5.8) min] and q-ML [116.8 (11.2) min] phases and did not differ from those
of the non-users. It was concluded that oral contraceptive use had little or no influence on
tolerance to uncompensable heat stress, whereas tolerance was increased during EF for
non-users of oral contraceptives.

12: J Appl Physiol. 1999 May;86(5):1519-26.

Exercise VE and physical performance at altitude are not affected by menstrual cycle phase.

eidleman BA, Rock PB, Muza SR, Fulco CS, Forte VA Jr, Cymerman A. Thermal and Mountain Medicine
Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts
01760, USA. [email hidden]

We hypothesized that progesterone-mediated ventilatory stimulation during the midluteal phase of the
menstrual cycle would increase exercise minute ventilation (VE; l/min) at sea level (SL) and with
acute altitude (AA) exposure but would only increase arterial O2 saturation (SaO2, %) with AA
exposure. We further hypothesized that an increased exercise SaO2 with AA exposure would enhance O2
transport and improve both peak O2 uptake (VO2 peak; ml x kg-1 x min-1) and submaximal exercise time
to exhaustion (Exh; min) in the midluteal phase. Eight female lowlanders [33 +/- 3 (mean +/- SD) yr,
58 +/- 6 kg] completed a VO2 peak and Exh test at 70% of their altitude-specific VO2 peak at SL and
with AA exposure to 4,300 m in a hypobaric chamber (446 mmHg) in their early follicular and
midluteal phases. Progesterone levels increased (P < 0.05) approximately 20-fold from the early
follicular to midluteal phase at SL and AA. Peak VE (101 +/- 17) and submaximal VE (55 +/- 9) were
not affected by cycle phase or altitude. Submaximal SaO2 did not differ between cycle phases at SL,
but it was 3% higher during the midluteal phase with AA exposure. Neither VO2 peak nor Exh time was
affected by cycle phase at SL or AA. We conclude that, despite significantly increased progesterone
levels in the midluteal phase, exercise VE is not increased at SL or AA. Moreover, neither maximal
nor submaximal exercise performance is affected by menstrual cycle phase at SL or AA.

13: Eur J Appl Physiol Occup Physiol. 1998 Nov;78(6):565-72.

Effects of menstrual cycle phase and oral contraceptive use on intermittent exercise.

Lynch NJ, Nimmo MA.

Scottish School of Sport Studies, University of Strathclyde, Glasgow, UK.

Five women using low-dose, monophasic oral contraceptive (OC) agents (OC group) and ten normally
menstruating women (Non-OC group) performed a treadmill protocol to determine the effect of OCs and
the menstrual cycle (MC) on intermittent exercise performance and some commonly used metabolic
markers. The Non-OC group were tested once in the mid-follicular phase (MFP) and once in the late
luteal phase (LLP) of the MC, while the OC group performed their first test within 1 week of taking
the OC (T1) and their second test 1 week later (T2). Despite performance time being the same in both
groups [mean (SD), Non-OC group: 77.7 (14.9) s versus OC group: 77.7
(13.1)a], plasma ammonia concentration ([NH3]pl) was higher in the Non-OC group when compared to the
OC group throughout recovery (P < 0.05). No differences were found in blood lactate (BLa),
maximum heart rate or aural temperature (Tau) between groups. Within the Non-OC group Tau
increased with exercise in both phases (P < 0.05), however Tau was higher in the LLP at rest
[36.1 (.3) degrees C) and 1 min post-exercise [37.1 (.6) degrees C), when compared to the
MFP [35.8 (.3) and 36.9 (0.7) degrees C, rest and 1 min post-exercise respectively, P <
0.05]. Within the OC group T1 resulted in a higher peak BLa [11.2 (.4) mmol/l] and [NH3]pl
(143.0 (26.2) Umol/l] when compared to T2 [BLa, 9.6 (0.9); [NH3], 119.4
(13.2), P<0.05]. These results suggest that: (1) exercise performance does not vary between the
MFP and the LLP of the MC, nor does it appear to be affected by the number of days using
the OC, and
(14) an altered metabolism occurs both between groups (Non-OC versus OC) and within the OC group.

15: Am J Sports Med. 1998 Sep-Oct;26(5):614-9.

Erratum in: Am J Sports Med 2000 Sep-Oct;28(5):747.

Comment in: Am J Sports Med. 1999 Mar-Apr;27(2):270-1. Am J Sports Med. 2000 Jan-Feb;28(1):131.

Association between the menstrual cycle and anterior cruciate ligament injuries in female athletes.

Wojtys EM, Huston LJ, Lindenfeld TN, Hewett TE, Greenfield ML.

MedSport, Section of Orthopaedic Surgery, University of Michigan, Ann Arbor, USA.

Anterior cruciate ligament injury rates are four to eight times higher in women than in men. Because
of estrogen's direct effect on collagen metabolism and behavior and because neuromuscular
performance varies during the menstrual cycle, it is logical to question the menstrual cycle's
effect on knee injury rates. Of 40 consecutive female athletes with acute anterior cruciate ligament
injuries (less than 3 months), 28 (average age, 23 +/- 11 years) met the study criteria of regular
menstrual periods and noncontact injury. Details concerning mechanism of injury, menstrual cycle,
contraceptive use, and previous injury history were collected. A chi-square test was used to compute
observed and expected frequencies of anterior cruciate ligament injury based on three different
phases of the menstrual cycle: follicular (days 1 to 9), ovulatory (days 10 to 14), and luteal (day
15 to end of cycle). A significant statistical association was found between the stage of the
menstrual cycle and the likelihood for an anterior cruciate ligament injury (P = 0.03). In
particular, there were more injuries than expected in the ovulatory phase of the cycle. In contrast,
significantly fewer injuries occurred in the follicular phase. These hormones may be a factor in the
knee ligament injury dilemma in women.

16: Med Sci Sports Exerc. 1995 Mar;27(3):437-44.

Effects of menstrual cycle phase on athletic performance.

Lebrun CM, McKenzie DC, Prior JC, Taunton JE.

Allan McGavin Sports Medicine Centre, University of British Columbia, Vancouver, Canada.

The purpose of this study was to examine the effects of menstrual cycle phase on four selected
indices of athletic performance: aerobic capacity, anaerobic capacity, isokinetic strength, and high
intensity endurance. Sixteen eumenorrheic women (VO2max > or = 50 ml.kg-1.min-1) were tested during
the early follicular (F) and midluteal (L) phases of the menstrual cycle. Cycle phases were
confirmed by serum estradiol and progesterone assays. No significant differences were observed
between F and L tests in weight, percent body fat, sum of skinfolds, hemoglobin concentration,
hematocrit, maximum heart rate, maximum minute ventilation, maximum respiratory exchange ratio,
anaerobic performance, endurance time to fatigue (at 90% of VO2max), or isokinetic strength of knee
flexion and extension. Both absolute and relative VO2max, however, were slightly lower in L than in
F (F= 3.19 +/- 0.09.min-1, L = 3.13 +/- .08.min-1, P = 0.04; and F = 53.7 +/- 0.9
ml.kg-1.min-1, L = 52.8 +/- 0.8 ml.kg-1.min-1, P
= .06). These results suggest that the cyclic
increases in endogenous female steroid hormones of an ovulatory menstrual cycle may have a slight,
deleterious influence on aerobic capacity, with potential implications for individual athletes.
Nevertheless, the cycle phase did not impact significantly on the majority of the other performance
tests and cardiorespiratory variables measured in this study.

15: Clin Sports Med. 1994 Apr;13(2):419-41.

The effect of the phase of the menstrual cycle and the birth control pill on athletic performance.

Lebrun CM.

Department of Family Practice, Faculty of Medicine, University of British Columbia,
Vancouver, Canada.

Investigators are not in agreement on the effects of either the phase of the menstrual cycle, or the
administration of OCAs on athletic performance. It appears, however, that apart from subtle changes
in some variables, for most women there is no significant effect. Medals have been won and world
records set in any phase of the menstrual cycle, and also by women taking OCAs. In terms of
documentation of cycle phase, newer hormonal measurement techniques such as the levels of urinary
luteinizing hormone (LH) to detect ovulation or salivary progesterone, should make it easier in the
future to obviate the methodologic difficulties encountered in earlier studies. Further studies
should also focus on the midcycle estradiol surge as well, in order to determine the relative
contributions of estrogen and progesterone to any observed performance changes. Given the
possibility that some cardiovascular, respiratory, and metabolic variables may change slightly
during the course of a regular ovulatory menstrual cycle, it behooves researchers who are using
women as subjects in other types of studies to standardize the menstrual cycle phase in which they
are tested, in order to eliminate any possible confounding effects due to hormonal variation.
Regarding the effects of oral contraceptives on performance, any conclusions from the studies to
date are complicated by the proliferation of preparations currently on the market. Further studies
are needed on monophasic, biphasic and triphasic formulations, including OCAs with the newer
progestins (desogestrel, gestodene and norgestimate), as well as the progesterone-only agents (both
oral and injectable). Prospective double blind randomized studies must be done, using a proper
control group. The difficulty with this technique, however, is that women in the control group will
inevitably be in various phases of the cycle, so accurate hormonal documentation is also essential
in order to correctly interpret the findings. Just as the past few decades have seen a significant
advancement in the participation of women in sports, future years should bring an enhanced
scientific knowledge base about the interactions of the special hormonal considerations of the
exercising woman throughout her reproductive life cycle.

PIP: Research has not yet conclusively settled the question of potential effects of oral
contraceptives (OCs) or of the phase of the menstrual cycle on athletic performance. The current
evidence suggests that most women's athletic performance is not affected by OCs or the phase of the
menstrual cycle. In fact, female athletes have won competitions and set world records at all phases
of the menstrual cycle. Even though many female athletes use OCs, the sports medicine community
knows little about the possible OC-induced metabolic effects on athletic performance. Sports
medicine researchers can use newer hormonal measurement techniques (e.g., urinary luteinizing
hormone levels) to detect ovulation or salivary progesterone, which avoid the methodological
difficulties in earlier studies. They should also concentrate on the midcycle estradiol surge to
learn the relative contributions of estrogen and progesterone to changes in athletic performance.
Since some cardiovascular, respiratory, and metabolic variables may change during a regular
menstrual cycle, researchers should also standardize the menstrual cycle phase in which female
athletes are tested to control for any possible confounding effects caused by hormonal variation.
The increase in the variety of OC preparations available to women complicate any conclusions about
the effects of OCs.

The Menstrual Cycle and Exercise Performance (last 11 references were truncated in the
prior posting)

15: Clin Sports Med. 1994 Apr;13(2):419-41.

The effect of the phase of the menstrual cycle and the birth control pill on athletic performance.

Lebrun CM.

Department of Family Practice, Faculty of Medicine, University of British Columbia,
Vancouver, Canada.

Investigators are not in agreement on the effects of either the phase of the menstrual cycle, or the
administration of OCAs on athletic performance. It appears, however, that apart from subtle changes
in some variables, for most women there is no significant effect. Medals have been won and world
records set in any phase of the menstrual cycle, and also by women taking OCAs. In terms of
documentation of cycle phase, newer hormonal measurement techniques such as the levels of urinary
luteinizing hormone (LH) to detect ovulation or salivary progesterone, should make it easier in the
future to obviate the methodologic difficulties encountered in earlier studies. Further studies
should also focus on the midcycle estradiol surge as well, in order to determine the relative
contributions of estrogen and progesterone to any observed performance changes. Given the
possibility that some cardiovascular, respiratory, and metabolic variables may change slightly
during the course of a regular ovulatory menstrual cycle, it behooves researchers who are using
women as subjects in other types of studies to standardize the menstrual cycle phase in which they
are tested, in order to eliminate any possible confounding effects due to hormonal variation.
Regarding the effects of oral contraceptives on performance, any conclusions from the studies to
date are complicated by the proliferation of preparations currently on the market. Further studies
are needed on monophasic, biphasic and triphasic formulations, including OCAs with the newer
progestins (desogestrel, gestodene and norgestimate), as well as the progesterone-only agents (both
oral and injectable). Prospective double blind randomized studies must be done, using a proper
control group. The difficulty with this technique, however, is that women in the control group will
inevitably be in various phases of the cycle, so accurate hormonal documentation is also essential
in order to correctly interpret the findings. Just as the past few decades have seen a significant
advancement in the participation of women in sports, future years should bring an enhanced
scientific knowledge base about the interactions of the special hormonal considerations of the
exercising woman throughout her reproductive life cycle.

PIP: Research has not yet conclusively settled the question of potential effects of oral
contraceptives (OCs) or of the phase of the menstrual cycle on athletic performance. The current
evidence suggests that most women's athletic performance is not affected by OCs or the phase of the
menstrual cycle. In fact, female athletes have won competitions and set world records at all phases
of the menstrual cycle. Even though many female athletes use OCs, the sports medicine community
knows little about the possible OC-induced metabolic effects on athletic performance. Sports
medicine researchers can use newer hormonal measurement techniques (e.g., urinary luteinizing
hormone levels) to detect ovulation or salivary progesterone, which avoid the methodological
difficulties in earlier studies. They should also concentrate on the midcycle estradiol surge to
learn the relative contributions of estrogen and progesterone to changes in athletic performance.
Since some cardiovascular, respiratory, and metabolic variables may change during a regular
menstrual cycle, researchers should also standardize the menstrual cycle phase in which female
athletes are tested to control for any possible confounding effects caused by hormonal variation.
The increase in the variety of OC preparations available to women complicate any conclusions about
the effects of OCs on athletic performance from existing studies. Researchers need to conduct
performance studies in women using the monophasic, biphasic, and triphasic OC formulations,
including those with the newer progestins (desogestrel, gestodene, and norgestimate), and the oral
and injectable progestin-only contraceptive agents. They also need to conduct prospective double
blind randomized trials using a proper control group. These studies should include accurate hormonal
documentation to correctly interpret the findings. This article reviews athletic performance; the
menstrual cycle; estrogen and progesterone effects; menstrual irregularities; metabolic,
respiratory, cardiovascular, hemodynamic responses; and strength.

16: Sports Med. 1993 Dec;16(6):400-30.

Effect of the different phases of the menstrual cycle and oral contraceptives on athletic
performance.

Lebrun CM.

Allan McGavin Sports Medicine Centre, University of British Columbia, Vancouver, Canada.

The female athlete, during her reproductive years, has a complex and ever-changing milieu of female
steroid hormones, whether it is the endogenous variations in estradiol and progesterone of a regular
menstrual cycle, or the exogenous synthetic hormones of the oral contraceptives. Both estrogens and
progestins have individual, interactive and sometimes opposing physiological actions with potential
implications for the exercising female. In retrospective surveys on the menstrual cycle and
performance, from 37 to 63% of athletes did not report any cycle 'phase' detriment, while 13 to 29%
reported an improvement during menstruation. The best performances were generally in the immediate
postmenstrual days, with the worse performances during the premenstrual interval and the first few
days of menstrual flow. However, this type of study has an inherent built-in bias, and is further
limited by the lack of substantiation of cycle phase. Many of the women studied associated
premenstrual symptoms, such as fluid retention, weight gain, mood changes, and dysmenorrhoea with
performance decrement. Such factors have also been causally linked with an increase in traumatic
musculoskeletal injuries during the premenstrual and menstrual period. Neuromuscular coordination,
manual dexterity, judgement and reaction time for complex tests have been shown to be adversely
affected in women with premenstrual syndrome or symptoms, but confounding variables may include
nutrition status and blood sugar levels. In addition, not all women suffer to the same level with
premenstrual symptoms. Fluctuations in many physiological functions occur throughout the normal
menstrual cycle. Results of early studies are difficult to interpret owing to the small numbers of
women studied, wide range of fitness levels, and variability in the definitions of cycle phase.
Nevertheless, investigators did not document any significant changes in measures of athletic
performance as a function of timing of testing during the menstrual cycle. Swimmers have shown a
premenstrual worsening of performance times, with improvement during the menstrual phase and on the
eighth day of the cycle. An increase in perceived exertion was noted premenstrually and during the
early menstrual stage with very intense exercise. In cross-country skiers, the best times were
recorded in the postovulatory and postmenstrual phases, prompting the recommendation that training
loads be selected according to cycle phase to achieve maximum benefit. Investigations using
estradiol and progesterone levels as a confirmatory index of ovulation have not generally found
significant differences across the cycle in either maximal or submaximal exercise responses,
although a slight decrease in aerobic capacity during the luteal phase has been reported.(ABSTRACT
TRUNCATED AT 400 WORDS)

17: J Appl Physiol. 1992 Feb;72(2):543-8.

Menstrual cycle phase affects temperature regulation during endurance exercise.

Pivarnik JM, Marichal CJ, Spillman T, Morrow JR Jr.

Department of Health and Human Performance, University of Houston, Texas 77204.

We investigated whether menstrual cycle phase would affect temperature regulation during an
endurance exercise bout performed at room temperature (Ta) of 22 degrees C and 60% relative
humidity. Nine eumenorrheic women [age 27.2 +/-
18.7 yr, peak O2 uptake (VO2) 2.52 +/- 0.35 l/min] performed 60 min of cycle exercise at 65% of peak
VO2. Subjects were tested in both midfollicular
(W) and midluteal (L) phases, although one woman did not show a rise in serum progesterone (P4) that
is typically evident 1 wk after ovulation. VO2, rectal (Tre) and skin (Tsk) temperatures, heart
rates (HR), and ratings of perceived exertion (RPE) were measured throughout exercise. Sweat
loss (SL) was estimated from pre- and postexercise body weight differences. VO2, SL, and Tsk
were not affected by menstrual cycle phase. Preexercise Tre was 0.3 degrees C higher during L
than during F conditions, and this difference increased to 0.6 degrees C by the end of exercise
(P less than 0.01). Compared with F, HRs during L were approximately 10 beats/min greater (P
less than 0.001) at all times, whereas RPE responses were significantly greater (P less than
0.01) by 50 min of cycling. No differences in any measured values were found in the subject
whose P4 was low in both test conditions. Results indicate that thermoregulation (specifically,
regulation of Tre), as well as cardiovascular strain and perception of exercise, was adversely
affected during the L phase.

18: J Sports Med Phys Fitness. 1991 Dec;31(4):532-7.

Variations in performance in simple muscle tests at different phases of the menstrual cycle.

Davies BN, Elford JC, Jamieson KF.

Department of Physiology, Faculty of Basic Medical Sciences, Queen Mary and Westfield College,
London, England.

The effect of the menstrual cycle on the performance of women in sporting activities is a very
confused subject. In this study, performances in simple muscle tests--the handgrip and standing long
jump, were studied at three phases of the menstrual cycle--menstrual (day 1-4), follicular (day
12-14) and luteal (day 19-21). Within subject paired "t" testing showed that in the handgrip test,
performance was significantly superior during the menstrual phase than those during both the
follicular and luteal phases. In the standing long jump test, performance was again superior during
the menstrual phase, although not significantly with respect to the luteal phase. This finding is
discussed in terms of the reported effects of the menstrual cycle on sporting performance, the
variation in the types of

hormones.

19: Med Sci Sports Exerc. 1990 Oct;22(5):575-80.

Effects of menstrual phase and amenorrhea on exercise performance in runners.

De Souza MJ, Maguire MS, Rubin KR, Maresh CM.

Department of Sport, Leisure and Exercise Science, University of Connecticut, Storrs 06268.

There are few well controlled studies in terms of subject selection, menstrual classification, and
exercise protocol that have examined both maximal and submaximal exercise responses during different
phases of the menstrual cycle in eumenorrheic runners and compared these runners to amenorrheic
runners. Thus, the purpose of this study was to measure selected physiological and metabolic
responses to maximal and submaximal exercise during two phases of the menstrual cycle in
eumenorrheic runners and amenorrheic runners. Eight eumenorrheic runners (29.0 +/- 4.2 yr) and eight
amenorrheic runners (24.5 +/- 5.7 yr) matched for physical, gynecological, and training
characteristics were studied. The eumenorrheic runners performed one maximal and one submaximal (40
min at 80% VO2max) treadmill run during both the early follicular (days 2-4) and midluteal (6-8 d
from LH surge) phases. The amenorrheic runners performed one maximal and one submaximal (40 min at
80% VO2max) treadmill run. Cycle phases were documented by urinary luteinizing hormone and
progesterone assays and by plasma estradiol and progesterone assays. No differences were observed in
oxygen uptake, minute ventilation, heart rate, respiratory exchange ratio, rating of perceived
exertion, time to fatigue (maximal), and plasma lactate (following the maximal and submaximal
exercise tests) between the follicular and luteal phases in the eumenorrheic runners and the
amenorrheic runners. We conclude that neither menstrual phase (follicular vs luteal) nor menstrual
status (eumenorrheic vs amenorrheic) alters or limits exercise performance in female athletes.

20: Int J Sports Med. 1989 Aug;10(4):264-9.

The menstrual cycle and exercise: performance, muscle glycogen, and substrate responses.

Nicklas BJ, Hackney AC, Sharp RL.

Exercise Biochemistry Laboratory, Iowa State University, Ames 50010.

Six eumenorrheic females (age = 26.3 +/- 2.4 yrs; X +/- SE) exercised until exhaustion (EE; 70%
VO2max) at the midluteal (LP, 7-8 days after ovulation) and midfollicular (FP, days 7-8) phases of
their menstrual cycles. Phases were confirmed by estradiol and progesterone concentrations. Each EE
test was preceded by a depletion exercise bout (DE; 90 min, 60% VO2max and 4 x 1 min, 100% VO2max)
and 3 days of rest/diet control. Muscle biopsies 1% (vastus lateralis) were taken post-DE, pre-EE,
and post-EE and then analyzed for glycogen content. There was a strong tendency (P less than .07)
for EE duration to be greater during LP
(21.2 +/- 14.9 min) than FP (126 +/- 17.5 min). Glycogen repletion (pre-EE minus post-DE) following
DE was greater (P = 0.05) during the LP than FP (88.2 +/- 4.7 vs 72.8 +/- 5.7 mumol/g w.
w. muscle). However, EE glycogen utilization (pre-EE minus post-EE/EE time) did not differ between
phases (LP = 0.41 +/- 0.08 mumol/g w. w. muscle/min vs FP = 0.33 +/- 0.11 mumol/g w. w.
muscle/min; P = 0.17). The results suggest that exercise performance and muscle glycogen content
are enhanced during the LP of the menstrual cycle. These findings imply athletic performance may
be affected by the phases of the menstrual cycle.

21: Med Sci Sports Exerc. 1987 Apr;19(2):111-7.

Exercise performance and ventilatory response in the menstrual cycle.

Dombovy ML, Bonekat HW, Williams TJ, Staats BA.

We investigated the effects of the luteal phase of the menstrual cycle, as compared with the
follicular phase, on ventilatory response (VR) and exercise performance in eight normally
menstruating, non-athletic women. Subjects were studied near the predicted mid-point of each phase
which was later documented by serum progesterone level. Resting VR to hypercapnia was greater, and
VR to hypoxia tended to be greater in the luteal phase than in the follicular phase, but the
increases in VRs were unrelated to progesterone level. There were no differences in maximal oxygen
uptake, maximal duration of exercise, maximal heart rate, work efficiency, maximal ventilation
(VE), anaerobic (ventilatory) threshold, gas exchange, cardiac output, or oxygen delivery. The PaCO2
was lower, and pHa tended to be higher during exercise. VE per unit CO2 output (VE/VCO2) was
increased. R values (VCO2/VO2) were less, and maximal lactate values tended to be less,
suggestive of increased dependence on fat for energy metabolism. At a given workload, exercise
VE was unchanged due to the effect of less CO2 output at a given VO2 (lower R), balancing
increased VE/VCO2. We conclude that, although ventilatory parameters are altered by the
menstrual cycle, there is no overall effect on maximal exercise performance.

22: Sports Med. 1984 Nov-Dec;1(6):431-45.

The regular menstrual cycle and athletic performance.

Eston RG.

The study of fluctuations in athletic performance attributable to the menstrual cycle has been an
area of considerable interest and controversy for well over half a century. Studies have included
simple observations of performance in athletic events, and have also documented specific physical,
psychological and physiological changes as they relate to varying hormonal levels of the menstrual
cycle. Advantages and disadvantages to human performance have been attributed to various phases of
the cycle. Many investigators have documented evidence to suggest that the premenstrual phase is
often associated with decreased performance. Others have noted that there are specific physiological
changes, inherent in athletic performance, occurring in the follicular and luteal phases of the
menstrual cycle. However, it is evident that there is conflict within the literature. This review
considers the evidence for the cyclic effects of the regular or normal menstrual cycle on
performance. It examines surveyed evidence of the effects of the regular menstrual cycle on athletic
performance, effects on psychological and perceptual factors, maximum oxygen uptake, endurance and
time to fatigue, temperature, sweating, bodyweight, respiratory drive, blood lactate, carbohydrate
and lipid metabolism, and cardiovascular parameters. It is concluded that there is considerable
variation in the findings of the literature and that any reported variations in performance may well
be greatly influenced by intersubject variability, the nature of the exercise, and the nutritional
status of the athlete, as well as minor changes that could be attributable to the menstrual cycle.

23: Br J Sports Med. 1983 Mar;17(1):46-50.

Effects of menstruation and contraceptive pill on the performance of physical education students.

Bale P, Davies J.

Of the 109 specialist female physical education students who answered a detailed questionnaire on
menstruation and the contraceptive pill in relation to exercise, 91 (83.5%) reported that they
suffered menstrual problems. These included stomach ache, depression, abdominal cramps and backache.
Over two-thirds of the students considered that these problems adversely influenced their physical
performance. However, whether they had a mainly physiological or
psychological effect is not clear. Many of the students with menstrual problems thought that
exercise had a beneficial effect and helped alleviate their discomfort. A small number of students
reported problems such as amenorrhoea and reduced menses possibly due to excessive training. Just
under half the students in the investigation took the contraceptive pill, and though as many
students taking the pill complained of menstrual problems as those not taking it, they reported
less problems and to a lesser degree. Most students claimed that taking the contraceptive pill had
no effect upon their performance.

PIP: Of the 109 specialist female physical education students who answered a detailed questionnaire
on menstruation and the contraceptive pill in relation to exercise, 91
(83.5%) reported that they suffered menstrual problems. These included stomach ache, depression,
abdominal cramps, and backache. Over
84/3 of the students considered that these problems adversely influenced their physical performance.
However, whether they had a mainly physiological or psychological effect is not clear. Many of
the students with menstrual problems thought that exercise had a beneficial effect and helped
alleviate their discomfort. A small number of students reported problems such as amenorrhea and
reduced menses possibly due to excessive training. Just under 1/2 of the students in the
investigation took OCs, and though as many students taking the pill complained of menstrual
problems as those not taking it, they reported less problems and to a lesser degree. Most
students claimed that taking OCs had no effect on their performance. author's modified

85: J Appl Physiol. 1981 Dec;51(6):1493-9.

Effects of menstrual cycle on blood lactate, O2 delivery, and performance during exercise.

Jurkowski JE, Jones NL, Toews CJ, Sutton JR.

The effects of the menstrual cycle on cardiorespiratory variables, blood lactate, and performance
were studied in exercising females. Nine healthy subjects, 20--24 yr of age, were investigated in
midfollicular and midluteal phases of the menstrual cycle at 33, 66, and 90% of maximum power output
(light, heavy, and exhaustive exercise). Occurrence of ovulation was confirmed in all subjects by
measurement of progesterone, which increased from 0.6 +/- 0.1 (mean +/- SE) in the follicular to 8.9
+/- 2.2 ng/ml in the luteal phase. There was no difference in heart rate (HR), ventilation, O2
uptake, or CO2 output between the two phases during light and heavy exercise, and there was no
difference in HR at exhaustion. Cardiac output measured midway through light and heavy exercise
periods was not affected by the phase of testing. Time for which exhaustive exercise could be
maintained increased from 1.57 +/- 0.32 in the follicular to 2.97 +/- 0.63 min in the luteal phase
(P less than 0.02). Blood lactate was higher in the follicular phase after heavy exercise (6.62 +/-
0.8 vs. 4.92 +/- 0.5 mmol/l) (P less than 0.05) and at exhaustion (8.12 +/- 0.9
vs. 6.76 +/- 0.6 mmol/L) (P less than 0.01). A further study showed no effect of cycle phase on
lactate disappearance during exercise. We conclude that while aerobic performance and the
cardiorespiratory adaptations to exercise are not influenced by the phase of the menstrual
cycle, performance of high-intensity exercise is improved, and lactate production appears to be
decreased in the luteal phase when estradiol and progesterone levels are elevated.

25: J Appl Physiol. 1981 Jun;50(6):1300-5.

Respiratory drives and exercise in menstrual cycles of athletic and nonathletic women.

Schoene RB, Robertson HT, Pierson DJ, Peterson AP.

To investigate the influence of the midluteal and midfollicular phases of the menstrual cycle on
exercise performance and ventilatory drives, we studied six outstanding female athletes, six
controls with normal menstrual cycles, and six outstanding athletes who were amenorrheic. In all
menstruating subjects resting minute ventilation
(VF) and mouth occlusion pressures (P0.1) were higher in the luteal phase (p less than k0.0001 and p
less than 0.02, respectively),. Hypoxic (expressed as the hyperbolic shape parameter A) and
hypercapnic (expressed as S, deltaVE/delta PAco2) ventilatory responses were increase in the
luteal phase (p less than 0.01). The athletes had lower A values during the luteal phase than
the nonathletes (p less than 0.001). Maximal exercise response, expressed either as total
exercise time or maximum O2 consumption or CO2 production (VO2 max or Vco2 max) was decreased
during the luteal phase but was significantly different at a p less than 0.05 level only among
the nonathletes. Ventilatory equivalent (VE/VO2) during progressive exercise on a bicycle
ergometer was significantly increased during the luteal phase. The amenorrheic athletes showed
no changes between the two test periods. The luteal phase of the menstrual cycle induced
increases in ventilatory drives and exercise ventilation in both athletes and controls, but the
athletes, in contrast to controls, demonstrated no significant decrease in exercise performance
in the luteal phase.

26: Scand J Work Environ Health. 1975 Jun;1(2):120-7.

Female work capacity during the menstrual cycle: physiological and psychological reactions.

Gamberale F, Strindberg L, Wahlberg I.

Changes in physical and mental work capacity during the menstrual cycle were studied in 12 healthy
woemen with severe menstrual distress. Physiological and psychological tests were performed before,
during, and after menstruation. Heart rate, pulmonary ventilation, oxygen uptake, blood lactate
concentration, and perceived exertion were measured during work on a bicycle ergometer ar two
submaximal work loads corresponding to 40 and 70 %, respectively, of individual maximal oxygen
uptake. Mental work capacity was studied with the aid of performance tests of psychological
functions such as attention, short-term memory, perceptual speed, perception of time, and reaction
time. No change in heart rate or oxygen uptake could be observed over the three phases of the
menstrual cycle. However, pulmonary ventilation during work varied significantly. It was highest in
the menstrual phase. At the same heart rate exercise on the bicycle ergometer was perceived as more
exerting in the menstrual phase than in either the premenstrual or postmenstrual phase. Among the
performance tests significant results were obtained only in a test of reaction time, which was
slightly impaired during the menstrual phase. The results of the performance tests do not however
support the assumption that menstruation affects a woman's mental work capacity.

I remain at quite a loss to describe the perceived comfort (in terms of temperature). I called on a
couple of people, but they couldn't suggest anything either.

Thanks also to Larry for posting those abstracts.

"diablo" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

This is an odd turn up. If your core temperature is above what it is

during

Quoted message said:

the regular cycle, you should feel "hot". I'm only taking a guess at this part, but sometimes,
what you perceive and what is actually happening in terms of thermoregulation are not always
related - take a fever for

example.

Quoted message said:

i would venture to guess its a diluted effect such as that. As for the

pool

Quoted message said:

being cold, it may feel cold to you, but its still like exercising in warm air.

"MSEagan" <[email hidden]> wrote in message news:bQzpb.74408$9E1.331939@attbi_s52...

Quoted message said:

Thanks for this information--very interesting. But would this apply if

one

Quoted message said:

Quoted message said:

is actually continuously cold while swimming, as is my case at the

Purdue

Quoted message said:

Quoted message said:

University pool ? In fact, if I could swim a little faster, like I seem

to

Quoted message said:

Quoted message said:

do at other times of the month, I can usually put myself just above this chill threshold because
I can go faster.

Although this may be a "politically incorrect" question....the facts are that men and women are
physically different (and wouldn't it be a boring world for many of us if we were not?)

Marianne

"diablo" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

This was an absolutely fantastic question as far as i am concerned (as

both

Quoted message said:

a coach and a physiologist), and i think i found the answer to your question. Orginially, i
thought of hormonal fluctuation, but wasn't

sure

Quoted message said:

Quoted message said:

how

Quoted message said:

much that would effect physical performance to such a noticeable

degree,

Quoted message said:

Quoted message said:

Quoted message said:

doing some reading, i found the following:

The bottom line is that during the period you discuss, the luteal

phase,

Quoted message said:

Quoted message said:

the

Quoted message said:

sweating response occurs at a higher temperature than normal (the

follicular

Quoted message said:

phase). This means that heat cannot be dissipated as normal, and the

core

Quoted message said:

Quoted message said:

temperature escalation leads to heat stress. The impairment of

performance

Quoted message said:

Quoted message said:

was found while working at both 60% of VO2Max, and at 80% VO2Max,

which

Quoted message said:

Quoted message said:

Quoted message said:

generally is where most swimming training takes place.

So lets take a field example of training for a marathon in july....essentially, for those few
days of the cycle, its similar to

running

Quoted message said:

at say 1pm in the afternoon, vs training at 5pm the rest of the month.

Hope that cleared it up for you, and thanks for asking it! 🙂

steve

"MSEagan" <[email hidden]> wrote in message news:SJxpb.70554$mZ5.437264@attbi_s54...
> OK. I have noticed this pattern for a long time now and would like

to

Quoted message said:

Quoted message said:

know

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> if there is a physiological explanation for my consistent slow down

that

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> seems to happen every month just about 4-5 days before the beginning

of

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> menstration. Even if I have no noticeable symptoms (e.g. cramps), I

get

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> slower, only to speed up again after about day 3 from the onset of menstruation. I have
> wondered if it is psychological, but many times

I

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> forget my dates and when I question why I am slower, I suddenly

remember

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the
> time of month.
>
> Marianne
>
>

Larry Weisenthal said:

There have been many studies performed trying to relate female athletic performance to phases of
the menstrual cycle. The conclusions have been that there are no consistent and clear-cut
relationships. I'll post a bibliography of these studies in the next day or so.

I could only read a few before losing interest - doesn't affect me!

But if they only focused on elite athletes, maybe not very useful. Many of those women barely have a
mentrual cycle.

For swimmers, is there a pronounced shift in fluid retention that could have a bearing on bouyancy?

--
Jason O'Rourke www.jor.com

"MSEagan" <[email hidden]> wrote in message news:SJxpb.70554$mZ5.437264@attbi_s54...

Quoted message said:

OK. I have noticed this pattern for a long time now and would like to know if there is a
physiological explanation for my consistent slow down that seems to happen every month just about
4-5 days before the beginning of menstration. Even if I have no noticeable symptoms (e.g. cramps),
I get slower, only to speed up again after about day 3 from the onset of menstruation. I have
wondered if it is psychological, but many times I forget my dates and when I question why I am
slower, I suddenly remember

the

Quoted message said:

time of month.

Marianne

I noticed the same thing. Same with increased appetite and moodiness and little extra sluggishness.
I think our bodies are using extra energy for physiological things that happen before the period.
And, it might be somewhat affected by our moods too.

"Larry Weisenthal" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

There have been many studies performed trying to relate female athletic performance to phases of
the menstrual cycle. The conclusions have been

that

Quoted message said:

there are no consistent and clear-cut relationships. I'll post a

bibliography

Quoted message said:

of these studies in the next day or so.

Plus, it's politically incorrect to even hint at the existence of such a relationship. Shame on
you guys.

- Larry W

Maybe not with all women. I've definately noticed a small change. Perhaps it's more noticeable with
poeople who are not in a top athletic shape, since their energy reserves are more limited. Also, not
all women are affected the same way. I know with me, it varies, depending on how careful I am with
nutrition and vitamins. If I start forgetting them, come that time of the month, it' extra tough.

Larry Weisenthal wrote: Just because you feel poo-poo

Quoted message said:

doesn't mean that you are going to swim poo-poo; if you give it your best effort, you'll probably
swim just as well, ... may just seem subjectively harder.

You took the words right out of my mouth...literally. Poo-poo is how I often describe my feelings
just before getting in and swimming a personal best. Yesterday, full of energy, cheery and eager and
...yes, you guessed, terribly swim. Happens all the time.

Ruth Kazez

rtk said:

You took the words right out of my mouth ... literally. Poo-poo is how I often describe my feelings
just before getting in and swimming a personal best. Yesterday, full of energy, cheery and eager
and ...yes, you guessed, terribly swim. Happens all the time.

I used to run fastest when I felt like garbage and I've even won tennis matches when I felt like
puking any second.

OTOH, famous women tennis players often blame inexplicable losses on the monthlies.

Donal Fagan AIA Donal@DonalO'Fagan.com (Anglicise the name to reply by e-mail)

Now I find this an interesting observation because on the nights when I have had almost no sleep for
one reason or another, I always anticipate my swim will be very difficult the next morning (of
course I would not consider skipping it!) and many times I end up swimming my best times on those
post sleepless nights. But, this premenstrual thing is another matter...I pushed today and managed
to keep my 500s between about 7:35 and 7:45 for 8000 yards but it was more difficult than I usually
find at other times of the month. Still, there are enough studies to indicate this should not be !
Thanks for taking the time to post them, Larry. Marianne

----- Original Message ----- From: "Larry Weisenthal" <[email hidden]> Newsgroups:
rec.sport.swimming Sent: Tuesday, November 04, 2003 12:19 PM Subject: Re: Swim Speed and
Menstrual Cycle

Quoted message said:

I am trying to be objective about this, based on the truly voluminous data which do exist, but
also to be reassuring. Just because you feel poo-poo doesn't mean that you are going to swim
poo-poo; if you give it your best effort, you'll probably swim just as well, ... may just seem
subjectively harder.

From: "MSEagan"

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I pushed

today and managed to keep my 500s between about 7:35 and 7:45 for 8000 yards <<

I could do that if I had a little rest between each of the 500s...say about a day's rest.