"John Banks" <[email hidden]> wrote
Quoted message said:I was doing fine until the 22.5 mile mark, about 2 minutes ahead of my
6:50 mile pace, but my quads started cramping up. Bad. Had to
walk/stretch/walk a few times.
John:
Good race. I predicted a 4 minute decrease in your marathon time due to
your lower level of training the last few weeks. I kept my mouth shut, but
that would have put you right at 3:00, imo.
The reason you didn't make it was the cramps. Cramps are not caused by heat
per se. They are caused when you lose more than x% of your body weight due
to dehydration. In my case it's about 4% (or 6 lbs). I will cramp every
time. If you had managed to drink another 1 or 2 quarts during your race,
you would have had your 3:00. 75 degrees won't slow you much at all if you
are thin and get enough to drink so you can sweat freely. You probably
didn't weigh yourself before and after, but I'd wager you had lost at least
4% of your body weight when you started cramping.
It took me a couple of years to figure this stuff out. I would cramp on
long races and was at my wits end. Everyone said it was a mineral
imbalance, and they were only partly right.
Here's the short course on hydration / salt /cramping: 16oz of sweat (1lb)
contains about 1/2 tsp of salt, about 600 mg. Say your sweat rate on a warm
day when racing is 32 oz/hour (mine is 40-50). After 2.5 hours (around mile
22 for you), you've lost 5 lbs of water and a lot of salt. If you've sipped
a 4 ounces at 5 aid stations, you're still down nearly 4 lbs -- 1/2 gallon!
Moreover, water has almost no salt, and sports drinks have alot less than
what's needed to replenish your stores.
When the body gets low on salt, your stomach gets queasy, and whatever you
drink sloshes around and doesn't absorb. So you don't drink, and a vicious
cycle ensues. The water sloshes because your body has to pump salt into
your stomach to absorb the water, and when you're low on salt (because of
copious sweating), the body is reluctant to do that because doing so will
further reduce your body's salt concentration. (very bad things can happen
if it gets too low, see Hyponatremia).
Solution: drink to approximate your fluid loss (you can be down a lb or two
without much noticable effect), and take a Succeed salt cap for every 16oz
you drink to keep your salt concentration stable. I carry a 24 oz bottle in
a belt pack which I refill every few miles and drink on the run about 6oz a
mile (my approximate fluid loss when racing a marathon). I find I can get
in enough water this way with very little lost time. I usually just take
one cap every time I refill the bottle.
Therefore, if you had taken a salt tablet and chugged 20-30 ounces at the
first sign of cramps, they would have disappeared within a minute or two.
Then you could have resumed your pace. I've recovered from cramps mid-race
twice, so it works. Taking a salt cap (I chew them so I don't have to wait
for the gelatin to dissolve in the stomach) with your water will cause it to
be absorbed amazingly quickly -- I've absorbed a quart in 2-3 minutes on a
100 degree day. I feel so bad for the cramped up runners I pass, but don't
have time to give them this lesson.
Good luck. You'll do it next time. You've got the training down, next
subject: fluid management. In the meantime you might want to do some
before/after weighing of yourself under various conditions to get an idea of
how your body dehydrates.
On shorter races like a 10k, I don't bother stopping at all lately. Being
down a couple of lbs isn't enough to slow me more than the time it takes to
drink the 32 ounces I lose...but marathons and ultras are a different story.
-- Dan
