Outside Magazine’s October “special fitness issue” contains a five page article by Tim Ferriss (of Four Hour Work Week fame) containing “the best tactics, routines and insider tricks…” to improve fitness and health. The article is packed with things Mr. Ferris has tried and found helpful. I thought it would be interesting to examine some of his “tactics” to see if science holds them up as viable ways to become more fit and healthy. Now, let’s be clear here: I am not a hater, but rather a lover of science and evidence.
First up:” Heat is the new black.” In this tip Mr. Ferris references a podcast done on his show by Rhonda Patrick, PhD. In the podcast, Dr. Patrick discusses taking a sauna after a work out and suggests that it has several helpful effects. She references a study done with six male runners, endurance runners or triathletes, average age 23, who either took a sauna after a work out or did usual post exercise cool down. The study showed that in this population, runners that took a sauna after a work out were able to run 32% longer than those that didn’t. This is hardly great science, and it is not necessarily applicable to all.
In addition, Dr. Patrick suggests that taking a sauna will improve hypertrophy during immobilization, (I.e. if you are injured and unable to move!) The scientific support she supplies is from a study on immobilized rats (27 rats with plaster casts on crutches!) In the study, the rats that took saunas had bigger leg muscles than those that didn’t sauna. I don’t think this can be generalized to immobile humans.
Taking a sauna after a work out will likely not hurt you if you use heat in a rational manner. It may even help, and I will consider adding this to my work out routine. However, I don’t think there is enough convincing evidence that it will improve endurance and muscle hypertrophy. More evidence is necessary.
BTW: I subscribe to Outside Magazine. I just don’t subscribe to everything I hear and read. For your pleasure, here is a p0dcast about “heat stress” from Dr. Patrick. Click the blue links for the studies.