1) Plain water is fine for shorter workouts, but if you’ll be exercising for longer than an hour, bring a sports drink or two to replenish your carbohydrates and electrolytes.
2) The night before a hot-weather workout, eat complex carbohydrates. The sugars will turn into glycogen, which will help your body hold onto its water supply.
3) Don’t count on your clothes to keep the sun’s radiation off your body. Polyester fabrics provide more protection than cotton, and dyed clothing is better than white, but both of those options also crank up the heat. Instead, purchase safe but cool sportswear with extra-tight knitting or sunscreen-treated fabrics.
4) Using a mirror, check your head for hair loss. Your mane may have thinned, especially at the crown, without you knowing it. Skin cancers develop more easily on the top of the head than any other part of the body, so if you can see your scalp through your hair, use a gel sunscreen or, even better, wear a hat while outside.
5) Take your antioxidants. Although research results vary, some studies have found that taking two grams of vitamin C and 1,000 IU of vitamin E provides extra protection against sun damage. Vitamins C, E and beta-carotene also facilitate healing if you get burned.
6) UV rays contribute to all kinds of eye problems, including cataracts and glaucoma, so purchase quality sunglasses. Make sure your glasses have both UVA and UVB protection and that they block light from the top and sides.
7) When you’re used to working out at room temperature, it’s easy to forget the toll that 80- or 90-degree days can exact. It can take a week or two to get acclimated to hot weather. Start with lighter workouts or by training early or late in the day. If you start getting tired more quickly than usual, quit early. And if you get a headache or feel dizzy, get out of the heat right away and drink more water.
8) Remember that heat stress is cumulative. You’re more likely to suffer from heat-related problems if you exercised in hot weather yesterday, even if today is relatively mild.
9) Re-choose your shoes. Low-top running shoes may be perfect for an indoor track, but once you start hitting dirt trails and rocky pathways, you’ll need the support of a trail-runner. If you’re traveling on concrete streets or sidewalks, make sure your shoes have plenty of padding or gel support to make up for the lack of “give” underneath.
10) Do what you can to avoid air pollution. If you live in a city, your local weather report will provide an Air Quality Index or Pollution Standards Index; when ozone or carbon-monoxide levels are over 100, consider moving your workout indoors. Avoid traffic-filled streets.
11) Keep a nose out for allergies. If left untreated, they can lead to asthma–a common problem among athletes–and other serious conditions. If you’re allergic to pollen (symptoms include a runny nose, itchy eyes, coughing and sneezing), plan your runs, hikes and bike rides away from any fields of weeds. Since pollen counts are highest in the morning, work out after 10 a.m. or stay inside. Shower well after outdoor exercise, and clean your nose with a saltwater rinse.
12) Medications and supplements can make you more sensitive to outdoor conditions, so consult your doctor or pharmacist. “Fat-burning” supplements often contain diuretics, which can lead to dehydration; caffeine and alcohol also increase water loss. Some antibiotics or antidepressants, including tetracycline and the herb Saint John’s Wort, can make your skin more sensitive to sunlight even if you’re wearing sunscreen.
13) Slather yourself with sunscreen before you leave home. Many such lotions need time to bond with chemicals in your skin; some take as long as 30 minutes to become fully effective. And bring the bottle with you, since even so-called “waterproof” sunscreens don’t last the length of a long, sweaty workout.
14) A little dehydration raises your heart rate while decreasing its efficiency, and a lot of dehydration is just plain dangerous. You should drink 16 to 32 ounces of water to prime the pump before you go outside, then bring plenty with you. Be sure to drink regularly throughout your workout, not just when you feel thirsty.
15) Take extra care when it’s humid. Sweat cools your body by evaporating into the air; if the air itself is full of moisture, the mechanism is much less efficient. That means warm, humid weather can affect you as much as or more than hot, dry weather.
16) Don’t do everything at once. Just because you’ve been pedaling an hour a day on a recumbent cycle doesn’t mean you can suddenly bike up a mountain without suffering pain and stiffness the next day. Get used to outdoor activities gradually, and you’ll have the whole summer to play outside.