Heat and Hydration: Exercising in the Heat
Exercising in the Heat
Exercise is one of the foundational pillars of health, so finding ways to make sure you stick with it at all times and in all situations is important for staying on track for your health and athletic goals. However, one aspect of this that requires quite a bit of attention is exercising when it’s warm or hot outside.
You’d may or may not be surprised, but even warm temperatures can lead to heat illness. Being able to recognize the signs and symptoms of heat illness are a good first step for planning. Medically speaking, heat illness is separated into heat exhaustion and heat stroke.
Heat exhaustion is defined by difficulty continuing with exercise, elevated heart rate (beyond the normal), weakness, light-headedness, headaches, nausea and muscle cramps. It is important to note that dehydration may or may not be present.
If heat exhaustion progresses, it can cause a heat injury, where there is an elevation of core body temperature and damage to the organs, but no change in a person’s mental status. Organs that are commonly damaged at this point include the muscles, kidneys and liver. Generally, a person’s core body temperature at this point is above 104 degrees.
The last stage of heat illness is heat stroke. This is seen as a change or loss in mental status (such as confusion, irrational behavior, irritability or altered consciousness) and a body temperature above 104 degrees. If not treated immediately, heat stroke can lead to death.
The good news is you can acclimate yourself to the heat. It generally takes about two weeks. More good news is that heat illness which is quickly recognized is easily treated with removal from the heat, cold water immersion and once the core body temperature is back to normal, recovery with fluids and rest.
Hydrating for Performance
You should begin all workouts in a well-hydrated state and maintain hydration throughout your workout or competition. By maintaining your hydration you can maximize performance, improve your ability to recover and minimize injury. If you begin an event in a dehydrated state or become dehydrated while exercising you can have an increased rate of physical and mental fatigue. As little as 2 to 3 percent decrease in body weight from water (sweat) loss can cause a decrease in performance. Other consequences of dehydration include increased core temperature and heart rate, decreased blood pressure, nausea, headaches and muscle cramping.
Fluid Intake Recommendations
Prior to exercise you should consume approximately 16 ounces of fluid 2-3 hours before and 8 ounces 15 minutes before. During exercise it is recommended to consume 4 ounces of fluid every 15 – 20 minutes. Post activity 16-20 ounces of fluid should be consumed for every pound of sweat lost.
Sports drinks are designed to rehydrate provide energy and replenish the body’s electrolytes. Sports drinks also contain carbohydrates the body’s main source of energy. During prolonged exercise it is important to replace fluid lost in sweat. Athlete’s that will benefit most from a sports drink are those that exercise for longer than 60 minutes and are heavy sweaters.
An important note about sports drinks is that while they help with electrolyte replenishment, they do not have enough electrolytes to completely replenish what you lose through sweating. To completely recover, proper meal planning is essential.
• Monitor your urine color. A clear pale yellow indicates you are well hydrated.
• Fruits and vegetables are mostly water and can aide in maintaining hydration.
• If you are a heavy sweater, eat salty foods before activity and replace sweat loss with a sports drink after.
• Carry a water bottle with you so you can drink water throughout the day and optimize your hydration