I used to feel proud about being drenched in sweat by the end of a workout. I held a common, but mistaken, belief that sweating buckets was helpful in losing fat and getting healthy.
The reality is that one can improve workout performance and results by cooling sufficiently to prevent sweating.
SWEATING IS UNHELPFUL
Sweat is water… not fat. Sweating does not promote or assist fat loss; and weight loss from sweating returns upon re-hydrating. When I used to run track, I’d lose about 7 pounds after every 45 minute practice. If I hadn’t gained that back each time, I would have gone completely out of existence in less than a month.
Consider the populations of Louisiana and Mississippi. I once stayed in Louisiana for a week during August… brutal. Due to the heat and humidity, it’s like being in a 24/7 sauna or heated-room yoga class. Yet, according to the CDC, people there are the fattest in the country. Sweating doesn’t seem to be helping them (despite the people there being the friendliest I’ve ever met!).
OVERHEATING REDUCES PERFORMANCE
One of the greatest impediments to athletic performance is overheating. When you’ve begun sweating, you have reached the point of overheating, and your muscles have become too warm to work maximally. This will lessen your workout performance, as most athletes will attest to. Lowered workout performance due to overheating will almost certainly reduce benefits from the workout, meaning less results.
My best running times as a high school student in Iowa were always when we had miserable weather: almost freezing temperatures, wind, and rain or snow. I would get angry at my coach for not letting the team wear more then the almost non-existent uniform of skimpy track shorts and tank tops in that weather. I thought he was just being mean, and I still think that. But whether he knew it or not, I now know that he was probably getting us to perform better than if we’d been wearing enough to keep comfortably warm.
A couple of Stanford University biology research scientists have been developing a technology to cool people more rapidly and effectively than previously possible. The benefits to performance and training seem to be profound. I am currently working to bring this to our gym to test in the very near future. You can see more details here: Stanford Magazine
SWEATING HAS DANGERS
Sweating can cause dehydration–which can be dangerous. Several years ago I ran in the Bix 7, a 7-mile road race in a humid climate next to the Mississippi River, and I saw one of the top female runners in the world collapse from dehydration/heat exhaustion while she was running. She nearly died.
SWEATING COSTS MONEY
Showering after a workout costs you time. A couple hours a week wasted could be worth $60 a week or more. Time is money in some ways, and incalculably more valuable in others.
INCREASED WARMTH REDUCES CALORIE BURNING
The same amount of work in a given routine will burn the same amount of calories and generate the same amount of heat. If that heat is not allowed to dissipate, but is built up within your body, then your body will bring its caloric expenditures to a screeching halt to prevent further heat build-up and maintain the narrow temperature range required for you to live.
To the extent your body warms above normal, your body will start restricting the amount of work you can do (performance drops), and other metabolic events which produce heat as a byproduct (the same ones that expend calories) will stop. If you get warm enough, you will pass out and go into a coma–with very little metabolic activity. To the extent that your body is warmed above normal, your metabolism will effectively slow down. (In contrast, a cold person must burn more calories in order to heat up.)
(As a side note, the medical literature considers that these reductions in metabolic events are results of excessive heat, rather than means of regulating it, but the effect is the same.)
If you do this same routine as above, but rapidly remove all of the increased heat from your body as it is generated, you would not feel warm, in spite of burning the same number of calories. You would not incur metabolic slow-down, and you would preserve the ability to function and do more work following the workout. This likely includes the ability to do more metabolic work immediately following a workout–meaning faster and better recovery, which would generate faster and greater results as well as more calories burned. This may account for the steroid-like improvements sometimes seen with the use of the cooling device in the article linked to above.
Further, rapidly removing all excess heat during and after exercise dramatically reduces or eliminates soreness. To me, this suggests investigating whether the unexplained phenomenon of muscle soreness has anything to do with the inability of the body to do certain metabolic work within heated muscles, that when not performed leads to soreness after muscle exertion.
What to Do:
Keep your workout environment cool enough (and dehumidified) to not break a sweat by the end of your workout, dress to allow your body to dissipate heat rapidly, and finish your workout quickly. Your workout will be more intense and you’ll get better results–while lowering any risk of dehydration or heat exhaustion.
Resist the temptation to wear layers to keep comfortably warm during your first one or two exercises, and you’ll be rewarded with a more productive workout. Sweatpants and long sleeve shirts trap heat, reducing performance and results, while shorts and tank tops will allow you to get more out of your workouts.
Remember that while muscular work can cause both fat loss and heat production, heating up and sweating are just byproducts of inefficient heat dissipation–they do not cause fat loss. You’ll improve results by increasing the intensity of muscular work while rapidly dissipating all heat produced and minimizing sweating.
At our facility in Los Angeles, we keep the temperature at 64 degrees or below, we keep the humidity low, and we direct a fan if you would still get too warm otherwise. A personal trainer leads you to complete an intense, full-body workout in under 20-30 minutes. Training this way, you don’t break a sweat, and don’t need to shower afterward. Yet you will perform better and get more results than had you spent an hour-plus sweating out a more conventional workout.
Thanks for this info, Chad. I was just talking with a friend about the value of keeping cool in workouts, and was happy to find it laid out so well on your website.