Mark A. Harrast, MD
Medical Director of
the Seattle Marathon Family of Events
UW Medicine - Sports
Medicine
Protect your skin
Apply sunscreen liberally and often for skin protection, as
solar radiation causes skin cancer.
Remember to apply it to any exposed skin – including your ears, scalp,
and back of your neck. Don’t forget to
wear a hat, sunglasses, and a shirt.
Stay hydrated
Running in the heat will increase sweating in order to
dissipate heat and keep your core temperature from rising too quickly. Increased sweating (without replacing fluid
lost thru sweat) will decrease your blood volume, which in turn, will decrease
blood and oxygen delivery to your working leg muscles, eventually slowing you
down. Drinking fluids to keep your blood
volume up will offset this effect and enhance your performance. But be careful – as drinking too much can
create other issues, including GI distress/bloating and hyponatremia (low blood
sodium). For most runners during a training run or race, drinking when you are
thirsty (ad libidum) is reasonable and effective. If your run route doesn't have ample water
fountains, then consider carrying a water bottle on your long run days. Finally, it’s as important to keep yourself
hydrated throughout the day when not running as it is during your runs. Having a hydration plan throughout the day
will help keep your total body water stores replenished and thus, similar to
fueling a gas tank in a car, you’ll be starting your runs off with your blood
volume “full” instead of closer to “empty.”
The current general
recommendation is to drink ~9-13 cups of fluid per day (which is a bit more
than the adage of eight 8-ounce glasses per day). This recommendation should be increased in
hotter climates and exercising individuals.
Prepare for hot weather
running
Are you accustomed to running in hot weather? Practice
running in the heat in preparation for hot weather races. It generally takes about two weeks to properly
acclimatize to exercising in hot weather. To begin acclimatizing, slow your pace (don’t
do speed workouts or harder efforts) during that first week of warmer weather
training, stay well-hydrated, and schedule adequate rest/recovery time.
Prevent heat illness
Avoid running during the hottest part of the day. Listen to your body and stop exercising, find
a shaded, cool area, and rehydrate (+/- seek medical attention) if you
experience lightheadedness, headaches, or you stop sweating. Wear light colored clothing to reflect the
sun’s rays. Synthetic fabrics are better
for exercising as they wick and dry easier, taking heat away from your body and
helping you to stay cool.
Set appropriate
expectations
Your body reacts differently on hot days. You won’t be able
to perform as well in the heat as you could on a cooler day, so slow your pace
during training runs and races on such hot days.
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