Dr. Aaron M. Flickstein
The August 7, 1981 issue of the Journal of the American Medical Association (JAMA) reported what is common knowledge today: Many people who run do so to place a demand on their cardiovascular system as well as to build muscle. What isn’t well known is that it also reported the “regular use of a sauna may impart a similar stress on the cardiovascular system, and its regular use may be as effective as a means of cardiovascular conditioning and burning of calories as regular exercise.”
It has been found that the infrared sauna makes it possible for people in wheelchairs, those who are otherwise unable to exert themselves, and those who won’t follow an exercising/conditioning program to achieve a cardiovascular training effect. It also allows for more variety in any ongoing training program. Blood flow during whole-body hyperthermia is reported to rise from a normal five to seven quarts a minute to as many as 13 quarts a minute.
Due to the deep penetration of infrared rays (over one and a half inches into body tissue), there is a deep heating effect in the muscle tissue and internal organs. The body responds to this heat with a hypothalamic-induced increase in both heart volume and rate. Beneficial heart stress leads to a soughtafter cardiovascular training and conditioning effect. Medical research confirms the use of a sauna provides cardiovascular conditioning as the body works to cool itself and involves substantial increases in heart rate, cardiac output, and metabolic rate. As a confirmation of the validity of this form of cardiovascular conditioning, extensive research by NASA in the early 1980’s led to the conclusion that infrared stimulation of cardiovascular function would be the ideal way to maintain cardiovascular
conditioning in American astronauts during long space flights.
Infrared Heat, Caloric Consumption, and Weight Control In its Wellness Letter, October 1990, the University of California Berkeley reported that “the 1980’s were the decade of high-impact aerobics classes and high-mileage training. Yet there was something elitist about the way exercise was prescribed: only strenuous workouts would do, you had to raise your heart rate to between X and Y, and the only way to go was to “go for the burn.” Such strictures insured that most ‘real’ exercisers were relatively young and in good shape to begin with. Many Americans got caught up in the fitness boom, but probably just as many fell by the wayside. As we’ve reported, recent research shows that you don’t have to run marathons to become fit – that burning just 1,000 calories a week…is enough. Anything goes, as long as it burns these calories.”
Guyton’s Textbook of Medical Physiology reports that producing one gram of sweat requires 0.586 kcal. The JAMA citation above goes on to state that “A moderately conditioned person can easily sweat off 500 grams in a sauna, consuming nearly 300 kcal – the equivalent of running two to three miles. A heatconditioned person can easily sweat off 600 to 800 kcal with no adverse effect. While the weight of water loss can be regained by rehydration, the calories consumed will not be.” Since a sauna helps generate two to three times the sweat produced in a conventional hot-air sauna, the implications for increased caloric consumption are quite impressive.
Assuming one takes a sauna for 30 minutes, some interesting comparisons can be drawn. Two of the highest calorie output exercises are rowing and running marathons. Peak output on a rowing machine or during a marathon burns about 600 calories in 30 minutes. An infrared sauna may better this from “just slightly” up to 250 percent by burning 900 to 2400 calories in the same period of time. It might in a single session simulate the consumption of energy equal to that expended in a six- to nine-mile run. The infrared sauna can therefore, play a pivotal role in both weight control and cardiovascular conditioning. It is valuable for those who don’t exercise and those who can’t exercise and want an effective weight control and fitness maintenance program, and the benefits regular exercise contribute to such a program.