Jones, Brandon C. Mr., “The Effect of Hyperthermic Whole Body Heat Stimulus (Sauna) on Heat Shock Protein 70 and Skeletal Muscle Hypertrophy in Young Males during Weight Training” (2017). All NMU Master’s Theses. 151.
Heat shock proteins (HSP) have gotten a bit of attention in the strength world recently. These are a family of proteins that are produced by cells in response to exposure to stressful conditions
A specific HSP called HSP70, plays a role as a molecular chaperone to protein in the process of skeletal muscle remodeling and has been hypothesized to act as a protective mechanism to muscle tissue. This may have implications for building muscle mass as well as recovery from training.
In a small, initial pilot study, the author set out to investigate whether stimulating heat shock protein 70 (HSP70) by using a sauna (45 – 50 ͦC, 80% Humidity) three times per week, for 15 minutes, could aid skeletal muscle hypertrophy during six weeks of resistance training in a young (21.38 ± 1.9 yrs.), recreationally trained male population.
The metrics studies were:
- Lean Body Mass (LBM),
- 5-rep max squat (5RM),
- Heat Shock Protein 70 concentrations (HSP70),
- delayed onset muscle soreness measured via the visual analog scale (VAS) in young males during six weeks of full body resistance training.
In order to take into account the relaxation benefits of sauna use, one group in the study used relaxation techniques for 15 minutes three times per week, instead of the sauna. Both the sauna group and the relaxation group resistance trained during the study. There was also a control group that did neither.
LBM, HSP70 changed the most from use of a hyperthermic stimulus (sauna) during resistance training, while their delayed onset muscle soreness remained the lowest.
5RM increased the most from the relaxation group.
It’s important to note that none of the changes were statistically significant so the author postulates that sauna use in combination with resistance training does not appear to augment muscle hypertrophy or strength, however, he suggests some of this may be due to the small sample size of the study, as well as the short length of time of the study.
One thing that is very interesting to note is that a possible explanation for the lower VAS scores in the sauna group may be due to hyperthermia causing vasodilation, which would increase oxygen availability and hydrogen ion removal, leading to a potential better recovery and subsequent workout. However, this remains speculative due to no statistical significance with the small sample size.
Hyperthermic stimuli (sauna) have many different physiological adaptations, such as increased heart rate, chronically reduced blood pressure, improved left ventricle heart function,reduced risk for cardiovascular disease in addition to an increase in HSP70. Other members of the heat shock protein family are also involved in skeletal muscle remodeling and were not measured in this study.
More research is needed to determine the effect of sauna use for recovery, muscle hypertrophy, and strength. Based on preliminary research, it appears there may be some promising links that warrant further investigation with larger sample sizes and longer studies.