What the fuck is “hyperthermic conditioning”? Enter Dr. Rhonda Patrick. Dr. Patrick has a B.S. degree in biochemistry from the University of California, San Diego. She has a Ph.D. in biomedical science from the University of Tennessee, and has done extensive research on aging, cancer, and nutrition. Her graduate research focused on the link between mitochondrial metabolism, apoptosis, and cancer. Quite the underachiever. I was first “introduced” to Dr. Patrick and Hyperthermic conditioning while reading Tim Ferriss’, Tools of Titans: The Tactics, Routines, and Habits of Billionaires, Icons, and World-Class Performers . He wrote that, “’Hyperthermic conditioning’ (calculated heat exposure) can help you to increase growth hormone (GH) levels and substantially improve endurance” (Ferriss, 7). As soon as I read the words “Increased GH levels” it was time to do some research.
Muscle growth can only occur if muscle protein synthesis exceeds that of muscle protein breakdown (Tipton). Various studies have shown that heat acclimation reduces the amount of protein degradation. This decrease in protein breakdown results in a net increase in protein synthesis subsequently resulting in an increase in muscle growth. Hyperthermic conditioning increases net protein synthesis in three primary ways: induction of heat shock proteins, induction of growth hormone, and the improvement of insulin sensitivity.
Both protein synthesis and the degradation of skeletal muscle are products of physical training. Working out increases the work load on the targeted skeletal muscle. With the increased workload comes the increase of the muscle cells’ energetic requirements. This demand for energy induces a process known as oxidative phosphorylation. Oxidative phosphorylation is, “the metabolic pathway in which cells use enzymes to oxidize nutrients, thereby releasing energy which is used to reform ATP” (Wiki). A result of oxidative phosphorylation is an oxidative protein damage known as “oxidative stress”. One study has shown that a 30-minute intermittent hyperthermic treatment at 41°C (105.8°F) in rats induced a 25% elevation of heat shock proteins in muscle and, importantly, this correlated with 30% more muscle regrowth than a control group during the seven days subsequent to a week of immobilization (Selsby). The author writes, “In summary, these data suggest that intermittent hyperthermia during reloading attenuates oxidative stress and improves the rate of skeletal muscle regrowth during reloading after immobilization” (Selsby).
The second manner in which hyperthermic conditioning can increase muscle mass is through stimulation in growth hormone. “One of its best-characterized effects is increasing levels of circulating insulin-like growth factor I (IGF-I)” (Velloso). IGF-1 affects hypertrophy in two different manners. Firstly, it stimulates protein synthesis via the mammalian target of rapamycin more commonly known as the mTOR pathway. Secondly, overall protein synthesis is increased as protein degradation is decreased via inhibition of the FOXO pathway (Schiaffino). These processes are shown in the image below.
According to Dr. Patrick in Tools of Titans (clickable link), “Two 20-minute sauna sessions at 80°C (176°F) separated by a 30 minute cooling period elevated growth hormone levels two-fold over baseline. Whereas, two 15 minute dry-heat sessions at 100°C (212°F) separated by a 30 minute cooling period resulted in a five-fold increase in growth hormone. The growth hormone effects generally persist for a couple of hours post sauna” (Ferris, 7).
The third and final manner which we will discuss is the increased insulin sensitivity that occurs during hyperthermic conditioning. It has been shown that insulin “can stimulate muscle protein synthesis provided that it increases blood flow and amino acid delivery to and availability for the muscle tissue” (Fujita). Additionally, insulin decreases protein degradation through a mechanism known as proteasome inhibition (Lecker).
So what does all of this mean? In short, if you want to get bigger, hit the sauna two to three times a week. To amplify the effects, implement hyperthermic conditioning immediately following your workout while you pound your protein shake.
- Bydan, Submitted1 Dayago, Submitted3 Daysago Byrhonda, and Submitted5 Daysago Bykeithbacker. "FMF > About Dr. Rhonda Patrick." FoundMyFitness. N.p., n.d. Web. 29 May 2017.
- Tipton, K. D., and R. R. Wolfe. "Exercise, protein metabolism, and muscle growth." International journal of sport nutrition and exercise metabolism.U.S. National Library of Medicine, Mar. 2001. Web. 19 May 2017.
- "Oxidative phosphorylation." Wikipedia. Wikimedia Foundation, 19 May 2017. Web. 19 May 2017.
- Selsby, J. T., S. Rother, S. Tsuda, O. Pracash, J. Quindry, and S. L. Dodd. "Intermittent hyperthermia enhances skeletal muscle regrowth and attenuates oxidative damage following reloading." Journal of Applied Physiology. American Physiological Society, 01 Apr. 2007. Web. 21 May 2017.
- Oksala, Niku K.J. et al. “Natural Thermal Adaptation Increases Heat Shock Protein Levels and Decreases Oxidative Stress.”Redox Biology3 (2014): 25–28. PMC. Web. 21 May 2017.
- Velloso, C. P. "Regulation of muscle mass by growth hormone and IGF-I." British Journal of Pharmacology. Nature Publishing Group, June 2008. Web. 24 May 2017.
- Schiaffino, Stefano, and Cristina Mammucari. "Regulation of skeletal muscle growth by the IGF1-Akt/PKB pathway: insights from genetic models." Skeletal Muscle. BioMed Central, 24 Jan. 2011. Web. 29 May 2017.
- Ferriss, Timothy. Tools of titans: the tactics, routines, and habits of billionaires, icons, and world-class performers. Boston: Houghton Mifflin Harcourt, 2017. Print.
- Fujita, Satoshi, Blake B. Rasmussen, Jerson G. Cadenas, James J. Grady, and Elena Volpi. "Effect of insulin on human skeletal muscle protein synthesis is modulated by insulin-induced changes in muscle blood flow and amino acid availability." American journal of physiology. Endocrinology and metabolism. U.S. National Library of Medicine, Oct. 2006. Web. 29 May 2017.