It's
easy to assume that because you don't actually see sweat when you're
swimming, you're not losing water. Not so. You not only sweat, but also
sweat copiously, because your body generates lots of internal friction
heat from the contractions of all those swimming muscle fibres. In fact,
75 percent of all the calories you burn in the pool are thrown off as
waste heat.
Prove it by weighing yourself before and after workout. You've lost
weight, and it's all water. Sweat losses of as little as 2 percent of body
weight, or 1.5Kg for a 68Kg swimmer, can dramatically hurt your practice
performance.
In fact, dehydration is far more likely to slow you down than energy loss,
making water loading far more important than carbo loading, not to mention
being easier. Still, though plain water is the most important "nutrient"
for achieving peak performance, it's not always considered to be the last
word these days, according to recent research.
A study by Dr. Jack Wilmore, an exercise physiologist at the University of
Texas, has concluded that for workouts of less than an hour, nothing beats
water. But if you're swimming for more than an hour, fluid replacement
drinks with electrolytes are absorbed into the bloodstream more quickly
than water, thus hastening recovery.
Sports drinks are easy enough to find, having made their way from
health-food and sporting-goods stores to the corner grocery. Besides
coming in a variety of brand names and flavours, their formulas are all
slightly different, so I can only advise people to experiment among the
brands. I settled on Gatorade, watered down to about half strength. I like
the taste, which prompts me to drink more; I've had no digestive problems,
and I've noticed a marked improvement during the latter half of a typical
75-minute workout.
Getting enough? Here are five ways to make sure.
1. You can sweat off 0.2 to 0.3 litres of fluid every 15 minutes. At
minimum that's a healthy swig from your water bottle every quarter hour.
2. Want to be more precise? Weigh yourself before and after a workout.
Each Kg lost is a 0.5 litres of water loss. Next time, bring that much in
your water bottle.
3. Pre-hydrate. Drink two to three cups of water about 2 hours before
swimming and another two cups 15 minutes before workout.
4. Drink before you're thirsty. The thirst response comes only after your
body already needs water. (Older swimmers note: Past middle age, we get
"less thirsty." Exercise that drives a younger person to drink probably
doesn't send thirst signals to an older person; so your risk of
dehydration is greater.)
5. Energy-replacement (carbo-loaded) drinks during workout? Not necessary
for a 2-hour or less workout. But if, say, you're getting on your bike
afterward, use them to tank up. |