Heat Training Tips

Should I change my workout on really hot days? 

It depends on your goals. Physical performance in a hot environment can be compromised in three basic ways. As your body’s core temperature increases, it: 

• Reduces the endurance capacity of the muscles.
• Increases the body’s reliance on carbohydrate for fuel.
• Compromises many aspects of cardiovascular function.

As you get used to the heat, you’ll be able to train harder and tolerate the heat better with these reminders: 

• During your first hot weather workouts, cut back on your exercise duration or intensity. Go easier. Train shorter. 
• Exercise in the early morning or evening when air temperature is likely to be cooler. 
• Monitor your heart rate. Slow down if your pulse is higher than your target zone or if you don’t feel good. 
• Drink plenty of fluids. Very critical. 
• Pick a training route that provides lots of shade: parks or tree-lined streets. 
• Know the symptoms of heat stress. If you have these symptoms stop, get cool, and rehydrate: nausea, dizziness, headache, chills, brain fog, muscle cramps, extreme out of breath, reduction or cessation of sweating.
• Train with others when it’s extra hot. They’ll notice if you are compromised.

What kind of clothing will keep me cool and protected? 

• Lightweight, loose, white, or light-colored moisture wicking fabrics help reflect the rays and allow better air circulation. 
• UPF fabrics that protect skin from UV radiation. UD long sleeves with UPF 20+ are a great option.
• Sunscreen with at least SPF 15 to protect against both UVA/UVB rays. 
• Visor or vented hat with a wide brim to protect your face and eyes. 
• Sunglasses
• Ice bandana 

What factors affect my ability to tolerate heat? 

You will generally be able to handle heat better when you are physically fit. Elderly individuals usually don’t tolerate heat as well as younger individuals, but this difference disappears when active and fit senior citizens are evaluated. Other things that reduce your ability to tolerate heat include: 

• sleep deprivation 
• infectious disease 
• excess body fat 
• high humidity 
• depleted muscle glycogen 
• poor cardiovascular fitness 
• sudden increase in training 

How can I teach myself to handle the heat better? 

The best way to promote heat acclimatization is through exercise training in a hot climate, particularly for athletes who will be competing under hot conditions. Continuous or intermittent aerobic training causes your body to acclimatize after about 7 to 14 days. Just make sure you start slowly and watch for signs of heat stress. For the first few days, exercise aerobically at about 60 to 70% of your maximal heart rate. Then gradually increase both your training intensity and volume. Adaptations that occur as you get used to the heat include: 

• earlier onset of sweating 
• higher sweat rates 
• lower body core temperature 
• increased blood volume 
• overall improved ability to tolerate heat
• lower heart rate response to submaximal workloads 

How much and what should I drink? 

In normal temperatures, the average sedentary person is recommended to drink approximately 0.5 ounce per pound of bodyweight of non-caffeinated, non-alcoholic beverages daily. Warm weather and exercise place even higher demands on the body for fluid. If you start an exercise session well hydrated, you’ll go a long way towards maintaining performance and personal safety. Water is the optimal beverage choice; however, fruit juices, smoothies, seltzer waters, milk and herbal teas are also choices -- be mindful of extra calories. Remember that beer, coffee and caffeinated soda draw fluid out of the body since alcohol and caffeine are diuretics, however, not as dramatically as previously believed. 

Don’t rely on thirst as an indicator of your body’s need for fluids. By the time you’re thirsty, you’re dehydrated. If your urine is dark and there’s not much of it, you’re dehydrated. Increase your fluid intake. Some general guidelines: 

• Drink fluids until your urine is pale yellow to clear and plentiful. 
• In general, drink as much fluid as you can comfortably tolerate both before, during, and after exercise. Drinking small amounts frequently usually works better than drinking a large amount once or twice. 
• Cool beverages are absorbed more quickly than warm beverages. 
• The stomach can only empty about 1 quart of fluid per hour into the body during exercise. If you drink more than that you could feel bloated. 
• You’ll often see athletes pouring cold water over their head during a race or competition. While this may provide some temporary relief, pouring enough cold fluid into the body is more effective in dealing with hot temperatures. 
• General guidelines for fluid intake are: 
• 2-3 cups about 2 hours before exercise
• 1 cup 5-10 minutes before exercise 
• 1 cup every 15-20 minutes during exercise, especially in warm weather 

What about sports drinks? 

If a vigorous exercise session lasts longer than 60 minutes, it’s a great idea to drink a sports beverage during the activity. You should choose something with a minimum of 4 to 8% carbohydrate along with electrolytes (sodium, potassium, magnesium, etc.) depending on the length of time you are exercising. My favorite is Electrolit, which provides all the above in an optimal ratio. It promotes fluid absorption while providing caloric energy. Many people consider sports drinks unpleasant during rest, but appreciate these lightly sweetened or flavored beverages while participating in sports. Athletes tolerate various beverages or sports drinks differently. Therefore you should never experiment with a new drink during a competition. Your training workouts are the time to try new and different options. 

Do the fluid recommendations change after I’m through exercising? 

Some athletes find it helpful to weigh themselves both before and after a workout. For every pound of weight you lose during a workout, drink 2.5 to 3 cups of fluid. Rehydration occurs faster in the presence of sodium (salt), regardless of whether this sodium is in a sports drink or food. 

To replace muscle glycogen stores and speed recovery from the workout, you should start replenishing carbohydrates within 15 minutes after exercise. You may not feel like eating so soon after a workout, but a sweetened beverage like Maurten Drink Mix will often hit the spot. You’ll get more carbohydrate per ounce of fluid if you opt for a caloric drink. 

What about heat cramps? 

Heat cramps are brief, often excruciating muscle contractions that can occur in athletes who sweat a lot, especially when exercising in a hot environment. Usually this happens because the person is exceeding a pace they are accustomed to and/or have lost a large amount of sodium chloride through sweating and hasn’t taken in enough sodium when replacing fluid losses. Mild heat cramps can be treated by drinking 1 liter (about 1 quart) of water with about 1/4 to 1/2 teaspoon salt dissolved in it. Athletes with normal or low blood pressure shouldn’t restrict their sodium intake. Salt tablets may help some athletes if they've trained with them, however, have been found to be a gastric irritant in some athletes. 

Heat acclimatization appears to reduce the incidence of heat cramps. Heat cramps can be prevented by following the above suggestions for fluid intake, having adequate sodium in your diet, and gradually progressing your training. 

How do I know if it’s too hot to exercise safely? 

Eighty to ninety percent of heat loss in a hot, dry environment is from the evaporation of sweat. However, in a humid environment, moisture in the air doesn’t allow the sweat on your body to evaporate as efficiently. Contrary to popular opinion, it’s the evaporation of sweat, not the sweat itself that cools us down. So exercise in humid heat is a lot riskier than exercise in dry, hot conditions. Check the weather chart below and if the “apparent temperature” is in the danger area, it’s a good day to take a break or exercise indoors.

Feel free to contact me if you have any questions or if you would like help in creating a training plan that is customized to your goals, your fitness level, and your lifestyle. Thank you for reading and sharing with a friend who might find this helpful!