When heat is on, handle it right
By Craig Horswill, Gatorade Sports Science Institute

 

Between the handball court and the showers, players often detour to the sauna, steam room or whirlpool to relax.

For some players, such facilities hold a mystique for healing the battered body. For others, these “hot boxes” are merely a source of voluntary torture.

Before stepping into such a hot environment, it is wise to know what is true and false about the effects of getting passively heated up.

Simply sitting in the sauna or steam room will not translate into acclimated condition for exercise in the summer.

 

Benefits … or not

 

Several physiological benefits have been attributed to sitting in a sauna, whirlpool or steam room. They include:

• An increase in metabolic rate.
• Cleansing of the pores.
• Burning of body fat.
• Purifying the body.

  For the most part, this is nonsense, though metabolic rate might rise slightly. Typical responses of our bodies to hot temperature include increasing the heart rate and increasing the blood flow to the skin. Also, there may be a small decrease in blood pressure. With these responses come a slight increase in the rate of resting energy expenditure, but only burning fat stored in the body.

  If one remains in the sauna for a long period, substantial sweat can be lost. Contrary to popular belief, sweating does not “purify” the body of contaminants. Rather it is the liver and kidneys that do the dirty work.

  The only purpose for sweating is to cool the body. In situations where the sweat rolls off the body without evaporating, such as in the steam room or the whirlpool, no evaporation takes place. So the body continues to sweat and eventually becomes dehydrated from the loss of water. Significant amounts of sodium also can be lost.

  Dehydration and sodium loss in a hot environment can lead to muscle cramps and heat illness. Such effects of the “hot box” alone are probably unlikely, though, since most handball players are sufficiently sane to leave the sauna or whirlpool well before this point.

  Nevertheless, when one combines a couple of drenching handball games with a post-workout sauna, dehydration and electrolyte losses could be substantial.

  A couple of other hypothetical benefits of the sauna are to assist in the warmup before a match and to help acclimate the body for exercise in upcoming warmer seasons.

  The process of warming up before exercising needs to occur internally–heat generated by the muscle with easy activities–and not externally–sitting in the sauna. A warmup in the sauna is effective only if the person performs stretching and calisthenics while in the sauna.

  Most would agree that sitting in the sauna or whirlpool provides some relaxation. The whirlpool is the most penetrating and may help tense muscles to relax. Whirlpool treatments have been used effectively for soft-tissue injuries. The heat and whirlpool action of the water may help blood flow to the site of damage, and the weightlessness may bring a brief relief to the injured limb.

  Whirlpool applications should be used under the guidance of an athletic trainer, physical therapist or physician. It is best for the handball player to consult with his or her personal doctor in using such a treatment for a sports injury.

   

An increase in metabolic rate.

• Cleansing of the pores.
• Burning of body fat.
• Purifying the body.

  For the most part, this is nonsense, though metabolic rate might rise slightly. Typical responses of our bodies to hot temperature include increasing the heart rate and increasing the blood flow to the skin. Also, there may be a small decrease in blood pressure. With these responses come a slight increase in the rate of resting energy expenditure, but only burning fat stored in the body.

  If one remains in the sauna for a long period, substantial sweat can be lost. Contrary to popular belief, sweating does not “purify” the body of contaminants. Rather it is the liver and kidneys that do the dirty work.

  The only purpose for sweating is to cool the body. In situations where the sweat rolls off the body without evaporating, such as in the steam room or the whirlpool, no evaporation takes place. So the body continues to sweat and eventually becomes dehydrated from the loss of water. Significant amounts of sodium also can be lost.

  Dehydration and sodium loss in a hot environment can lead to muscle cramps and heat illness. Such effects of the “hot box” alone are probably unlikely, though, since most handball players are sufficiently sane to leave the sauna or whirlpool well before this point.

  Nevertheless, when one combines a couple of drenching handball games with a post-workout sauna, dehydration and electrolyte losses could be substantial.

  A couple of other hypothetical benefits of the sauna are to assist in the warmup before a match and to help acclimate the body for exercise in upcoming warmer seasons.

  The process of warming up before exercising needs to occur internally–heat generated by the muscle with easy activities–and not externally–sitting in the sauna. A warmup in the sauna is effective only if the person performs stretching and calisthenics while in the sauna.

  Most would agree that sitting in the sauna or whirlpool provides some relaxation. The whirlpool is the most penetrating and may help tense muscles to relax. Whirlpool treatments have been used effectively for soft-tissue injuries. The heat and whirlpool action of the water may help blood flow to the site of damage, and the weightlessness may bring a brief relief to the injured limb.

  Whirlpool applications should be used under the guidance of an athletic trainer, physical therapist or physician. It is best for the handball player to consult with his or her personal doctor in using such a treatment for a sports injury.

   

For the most part, this is nonsense, though metabolic rate might rise slightly. Typical responses of our bodies to hot temperature include increasing the heart rate and increasing the blood flow to the skin. Also, there may be a small decrease in blood pressure. With these responses come a slight increase in the rate of resting energy expenditure, but only burning fat stored in the body.

If one remains in the sauna for a long period, substantial sweat can be lost. Contrary to popular belief, sweating does not “purify” the body of contaminants. Rather it is the liver and kidneys that do the dirty work.

The only purpose for sweating is to cool the body. In situations where the sweat rolls off the body without evaporating, such as in the steam room or the whirlpool, no evaporation takes place. So the body continues to sweat and eventually becomes dehydrated from the loss of water. Significant amounts of sodium also can be lost.

Dehydration and sodium loss in a hot environment can lead to muscle cramps and heat illness. Such effects of the “hot box” alone are probably unlikely, though, since most handball players are sufficiently sane to leave the sauna or whirlpool well before this point.

Nevertheless, when one combines a couple of drenching handball games with a post-workout sauna, dehydration and electrolyte losses could be substantial.

A couple of other hypothetical benefits of the sauna are to assist in the warmup before a match and to help acclimate the body for exercise in upcoming warmer seasons.

The process of warming up before exercising needs to occur internally–heat generated by the muscle with easy activities–and not externally–sitting in the sauna. A warmup in the sauna is effective only if the person performs stretching and calisthenics while in the sauna.

Most would agree that sitting in the sauna or whirlpool provides some relaxation. The whirlpool is the most penetrating and may help tense muscles to relax. Whirlpool treatments have been used effectively for soft-tissue injuries. The heat and whirlpool action of the water may help blood flow to the site of damage, and the weightlessness may bring a brief relief to the injured limb.

Whirlpool applications should be used under the guidance of an athletic trainer, physical therapist or physician. It is best for the handball player to consult with his or her personal doctor in using such a treatment for a sports injury.

 

Recovery after the recovery

 

Because sweating continues after leaving the sauna or whirlpool, the athlete will want to allow some time before changing into street clothes.

Of greater concern, standing in a shower can be stressful to the body, such as causing lightheadedness or dizziness, after spending tune in the sauna or whirlpool. It is a good idea to move around and cool off before entering the shower.

Fluids lost during sweating will need to be replaced. The drop in body weight detected between the beginning of a workout and the end of the sauna session is almost exclusively water lost from blood and muscle. The weight change is unrelated to fat reduction.

Fluid consumption should start even before the workout or sauna session is finished. For the most rapid recovery, a sports drink that contains glucose and sodium is advisable.

Most important, the player needs to replace the body fluids before the next workout or session in a “hot box.” If not, the player will begin the next exercise session in a dehydrated state, which increases the risk of suffering a poor game due to fatigue or, far worse, any injury from heat illness.

 

A word of caution

 

For most individuals, taking a sauna, steam or whirlpool offers only minor health risks. However, everyone is advised not to lie down in a sauna or steam room because of the low blood pressure and lightheadedness that can be experienced when the person later sits or stands.

Anyone with blood-pressure problems or vascular diseases is advised against using such facilities until they have received clearance from their personal physician.

Craig Horswill is a scientist in the Gatorade Exercise Physiology Laboratory.

For more information on health-related subjects, visit the Gatorade Sports Science Institute Web site at www.gssiweb.org.