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Neighbors of Kane County

Sweat the Truth

Aug 09, 2019 12:13PM


By Richard J. Wolff, RDN

In his New York Times bestselling book, Don’t Sweat the Small Stuff, author Richard Carlson encourages readers to not sweat the small stuff; good advice for a modern world. Today, I’m recommending you “Sweat the Truth” when it comes to strength training. Despite our best intentions, it’s easy to get pulled down rabbit holes that lead to nowhere. Not long ago, I found myself wondering down one such rabbit hole.

Advertisements from a local fitness center were promoting a weight-loss sauna that possessed revolutionary, calorie-burning, technology. According to the ad, a single session (i.e., sitting in the sauna) burns up to 800 calories. Curious about the technology, I contacted the business advertising it. When I asked, “How is it possible to burn 800 calories while sitting in a sauna?” the person on the phone said they had researched the sauna online. Their research led them to conclude that, as sweat evaporates from the body, calories are burned. Unfortunately, their conclusions are completely incorrect.

Guyton’s textbook of medical physiology states that, “as water evaporates from the body surface, 0.85 calories of heat are lost for each gram of water that evaporates”. However, losing heat through the evaporation of sweat does not mean your body is burning calories. Sweating in a sauna occurs because your body is absorbing heat, not burning calories. This process is called thermoregulation. It prevents heat illness by regulating body temperature. Thermoregulation, and the break down of chemical energy (burning calories), are two separate processes and not directly related.

According to Walter Thompson, Ph.D., professor of exercise science at Georgia State University, “sweating is the way your body cools itself. Post-exercise weight loss often represents a loss of fluids, not a reduction of bodyfat”. In their highly acclaimed book The Fat-Free Truth, fitness authors Liz Neporent and Suzanne Schlosberg tackle this issue by telling readers “don’t confuse sweating with fat burning”.

If it were possible to burn 800 calories while sitting in a sauna, you could expect to lose significant amounts of weight without moving your body or changing your diet. From a weight loss standpoint, this would make exercise and healthy eating obsolete. Exercise guidelines could be met by doing absolutely nothing. If you overate, you could burn off the calories by spending a few minutes in the sauna. This type of flawed thinking goes against established laws of physics and exercise science. Losing bodyfat and managing your health requires effort. This no effort approach to weight loss is exactly what the Federal Trade Commission warns against.

There’s no evidence demonstrating that sweating in a sauna leads to fat loss. However, there is evidence showing just the opposite! The Clinical Guidelines for Weight Loss and Weight Management, from the National Institutes of Health (NIH), provide clear evidence on what works for weight loss and weight loss maintenance. A summary of these finding was published in the Journal of Obesity Research. This comprehensive report was written by a panel of 24 members who are experts in medicine, clinical nutrition, exercise physiology and psychology. The report reviewed evidence from nearly 400 published studies and concluded that successful weight management is best achieved by participating in programs that focus on diet therapy, physical activity and behavioral therapy. The NIH report does not mention or recommend the use of saunas for weight loss.

You may be wondering how a business can get away with such bold, unsubstantiated claims. Unfortunately, there are no “Standards of Practice” within the fitness industry. Advertising frequently comes down to saying whatever you want. The majority of the time advertisement claims are not challenged. Ultimately, consumers suffer the most. Despite the availability of evidence-based guidelines (i.e., Physical Activity Guidelines for Americans, etc.), the Federal Trade Commission has limited funds to enforce Truth-In-Advertising laws.

Fortunately, we’ve come a long way when it comes to combating Strength Training deception. Published research consistently shows that intense, brief workouts provide life changing health benefits. In fact, the Second Edition of the Physical Activity Guidelines for Americans (the most comprehensive report of its’ kind) recommend that all adults strength train on a weekly basis. The best way to stay ahead of the curve and avoid rabbit holes is to become an Educated Consumer. Keep learning, ask good questions and always keep your thinking cap on!

MEDFITNESS is a strength training studio located in St. Charles: 630-762-1784


1. Physical Activity Guidelines for Americans.

2. Arthur C. Guyton, M.D. 1971, Textbook of Medical Physiology. W. B. Saunders Company. Philadelphia, PA.

3. Neporent, L., Schlosberg, S. 2005. The Fat-Free Truth. New York, NY. Houghton Mifflin Company

4. Medicina Sportiva. Med Sport 15 (3): 147-162, 2011DOI: 10.2478/v10036-011-0025-x. Evidence-Based Resistance Training Recommendations.

Source: Richard Wolff , a regular contributor to Neighbors Media, is founder and owner of MedFitness, St. Charles, a strength training studio that specializes in on-demand personal training.