Data (was PowerCranks Study)

As an athlete (swimming) who has somewhat latched onto recreational cycling, I'd like to know this:
what about the effects of cross training six other cyclists and measuring these changes? I'm sure 6
weeks of swimming/free dive training would increase VO2 max, HR, VO, and many other factors a
SIGNIFICANT amount BETTER than powercranks.

-Mike (VO2 max currently ~55, max ~57, age 19)

--On Monday said:

Here is a condensed preview of the numbers from the PC testing. The study was conducted by Mark D.
Luttrell, Dept of Health, Sport and Exercise Science, University of Kansas and Jeffrey A.
Pottteiger, Dept of Physical Education, Health and Sports Studies, Miami University.

The effects of 6 weeks of training with PCs was examined for 6 cyclists (+6 with regular
cranks) to determine changes in V02 max, AT, HR, V0, and RER during a 1 hour submaximal ride
(~69% V02 max).

Here are the numbers for Heartrate (HR) and Gross Efficiency (GE) before and after training.

Time (minutes)

PC Group 15 30 45 60

HR Pre 154 155 156 157

Post 141 140 141 141

GE (%)Pre 21.5 21.3 21.6 21.5

Post 23.1 23.0 23.6 23.9

Control Group

HR Pre 166 165 166 163

Post 159 159 159 160

GE (%) Pre 21.3 20.8 20.8 21.2

Post 21.8 21.5 21.3 21.0

Significant is the 2% increase in Gross Efficiency of the PC group.

Phil Holman

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

Quoted message said:

Here is a condensed preview of the numbers from the PC testing. ...

My immediate question is: Why did the control group have higher hear rates and lower efficiencies
(however that was calculated) than the PC group at the beginning of the test? Even if the PC group
showed greater improvement, it would seem that the two groups were not evenly matched to begin with.
Individuals in the PC group may have responded to whatever training program was implemented better
than the control group, with or without any equipment differences.

I would like to see some definitive results, the PC seem like an interesting training tool (but too
expensive for me).

-David

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

Quoted message said:

"Phil Holman" <[email hidden]> wrote in message

news:<[email hidden]>...

Quoted message said:

Quoted message said:

Here is a condensed preview of the numbers from the PC testing. ...

My immediate question is: Why did the control group have higher hear rates and lower efficiencies
(however that was calculated) than the PC group at the beginning of the test? Even if the PC group
showed greater improvement, it would seem that the two groups were not evenly matched to begin
with. Individuals in the PC group may have responded to whatever training program was implemented
better than the control group, with or without any equipment differences.

I would like to see some definitive results, the PC seem like an interesting training tool (but
too expensive for me).

I can email the entire research article if you like. I do not see any significance in the
differences between HR and GE in the pre-training test. It would be impossible to predict any bias
from dividing the 12 athletes into 2 groups assuming these were selected prior to the determination
of the pre-training data. Average scatter was around +/- 10 bmp for HR and +/- 2.0 for GE.

Phil Holman

Phil Holman said:

Here is a condensed preview of the numbers from the PC testing. The study was conducted by Mark D.
Luttrell, Dept of Health, Sport and Exercise Science, University of Kansas and Jeffrey A.
Pottteiger, Dept of Physical Education, Health and Sports Studies, Miami University.

The effects of 6 weeks of training with PCs was examined for 6 cyclists (+6 with regular
cranks) to determine changes in V02 max, AT, HR, V0, and RER during a 1 hour submaximal ride
(~69% V02 max).

Here are the numbers for Heartrate (HR) and Gross Efficiency (GE) before and after training.

Time (minutes)

PC Group 15 30 45 60

HR Pre 154 155 156 157

Post 141 140 141 141

GE (%)Pre 21.5 21.3 21.6 21.5

Post 23.1 23.0 23.6 23.9

Control Group

HR Pre 166 165 166 163

Post 159 159 159 160

GE (%) Pre 21.3 20.8 20.8 21.2

Post 21.8 21.5 21.3 21.0

Significant is the 2% increase in Gross Efficiency of the PC group.

Phil Holman

What is gross efficiency? How is it measured?

From the individual test reports I've read about PC (admittedly anecdotal, but then a test group of
6 is barely less so), it took 3 months of training with them to see major improvements. 6 weeks
seems a bit short.

trg said:

Phil Holman said:

Significant is the 2% increase in Gross Efficiency of the PC group.

What is gross efficiency? How is it measured?

From: bsn.comcadence.htmlOpen ↗

"[...] exercise efficiency has several precise definitions that are summarized in Gaesser and Brooks
(1975). They defined and compared four types of efficiency measures with the goal of identifying the
one that best represented human muscular efficiency. "These efficiency measures were 1 ) gross
efficiency, the ratio of the work accomplished to energy expended, that is, the effectiveness of
converting chemical energy into mechanical work; 2) net efficiency, the ratio of the work
accomplished to the energy expended above that during rest, that is, the cost of resting metabolism
is subtracted from the denominator in the computation; 3) work efficiency, the ratio of the work
accomplished to the energy expended above that during cycling with no load, calculated by
subtracting from the denominator the cost of moving the legs plus the resting metabolism, and 4)
delta efficiency - the ratio of the change in the power output to the change in the energy expended
at each power output."

As long as you can eat more food while riding, efficiency isn't really the most important limiter to
performance. That's why I'm more interested in whether anything else showed a significant
difference.