Do you ever turn beet-red during exercise? That happens because blood vessels below the skin in the face are dilating; as they widen, they transport heat from the muscles to the skin to cool off the body. Chances are, if you’re a person who turns bright red in the face during exercise, you may not sweat as much as a person who does not turn red; it usually has nothing to do with the amount of exercise you do or how much effort you’re putting into it. Which brings us to a related myth…
The fitter I get, the less I will sweat.
There’s no relationship between how fit you are and how much you sweat. Some people sweat buckets, while others don’t sweat much at all, regardless of their fitness level or degree of exertion. Heavy sweating during exercise may not be pleasant, but it means that the body is cooling itself efficiently, which may enhance your performance.
The only possible physiological downside of heavy sweating is that if you don’t replace the lost fluid by drinking water, you run the risk of dehydration. Dehydration is unhealthy for all people, but it can be even more of a concern for people with diabetes, because it is more likely to occur when blood glucose levels aren’t under control.
It’s relatively easy to dehydrate if you sweat a lot; on a hot, humid day, you can lose more than 5% of your body weight from sweat during a workout. Athletic performance can be adversely affected by as little as a 1% drop in body weight, and when fluid loss exceeds 3% of body weight, endurance can diminish by as much as 20% to 30%. Weight loss from sweat should never exceed 2% of body weight. (For a 150-pound person, 2% of body weight is 3 pounds.)
Thirst is not a good indicator of hydration status, because by the time you feel thirsty, you may already be dehydrated. Proper hydration, or fluid replacement, should begin before you exercise and continue during and after the activity. The amount of water you drink should approximately equal the amount of fluid lost in sweat and urine. To get a sense of how much fluid you need, weigh yourself nude before and after exercise and drink 2 cups of water for every pound lost. Some people can lose 1/2 to 2 liters of fluid per hour (1 liter of water weighs 2.25 pounds). A more general guideline for maintaining proper hydration is as follows:
- Drink 17 to 20 ounces of water (about 2–2 1/2 cups) 2 to 3 hours before exercise.
- Drink 7 to 10 ounces of water (about 1–1 1/2 cups) 10 to 20 minutes before exercise.
- Drink 7 to 10 ounces of water every 10 to 20 minutes during activity.
If you sweat heavily, you may need to drink more.
If I’m not sore after my workout, I’m not getting any benefit.
This myth may hail back to that old “no pain, no gain” adage that’s simply not true. Muscle soreness is not a prerequisite for muscle growth. When just starting an exercise program or a new activity, it’s common to feel stiff or sore for a day or more afterward. Once the body adapts to a particular exercise, however, you won’t feel as sore every time you work out, though clearly you are getting stronger. You can minimize muscle pain by beginning with small amounts of activity and only gradually increasing the intensity and duration of your workout.
If you’re already used to exercise, you know that you are capable of various degrees of intensity when working out. You don’t need to push to the limit at each workout to realize gains in performance (in fact, overdoing it can cause burnout or injury), but if you feel you’ve hit a plateau in your routine, and you consider a little soreness to be “good pain,” kicking your effort up a notch or two can help you reach your next fitness goal. Try lifting weights more slowly, particularly on the lowering portion of the lift, which tends to cause more soreness. You could also ask a spotter to help you with the final few repetitions once you’re fatigued and cannot complete a full repetition. You begin the lift on your own, and when you cannot lift any further, the spotter helps you finish the lift; you then lower the weight on your own. This is called assisted negative training, and it will help you build muscle.