NEW YORK -
Cooling down before warming up may help exercisers keep
going during the dog days of summer, according to a small
study. Researchers found that when they outfitted male
cyclists with special "precooling" garments before a
workout in the heat and humidity, the athletes showed
cooler body temperatures, lower heart rates and less
sweating. The cool down came courtesy of shirts and pants
with tubing that allowed cold water to run through the
clothes. Other studies have shown that a pre-workout dip
in a cold bath or exposure to cold air can help exercisers
lower their odds of heat strain in hot, humid weather. Dr.
Hein Daanen of the research institute TNO in the
Netherlands led this latest study, published in the
International Journal of Sports Medicine.
Physical activity causes the body's core temperature to
rise, with hot, humid weather spurring a particularly
rapid ascent; at a certain point, an exerciser must slow
down or risk heat-related illness. The idea of precooling
is to increase the body's heat tolerance by starting
exercise with as cool a body temperature as possible.
The current study included eight male cyclists who were
asked to ride in summer-like heat under each of four
conditions: after precooling just the upper body; after
cooling the lower body only; after a whole-body cool down;
and after no precooling.
Compared with the cooling-free ride, Daanen's team found,
the cyclists had fewer signs of heat strain during their
post-cooling rides. Also, contrary to the researchers'
expectations, precooling the leg muscles did not diminish
the athletes' performance, despite the fact that it's
generally considered a bad idea to work "cold" muscles.
Therefore, the researchers conclude, "it seems to be of no
importance" which body parts an athlete chooses to chill
before heading out into the heat.