The Sauna – A perfect time to relax and to increase your gains?
Many of us have seen the inside of a sauna on at least a couple of occasions. You may be surprised to know that your sauna visits have significant positive effects on your health and gains.
Heart rate during an intense sauna session may increase up to 100-150 beats per minute during a session, an increase that corresponds to low- and moderate level physical activity. Several studies have shown improved exercise capacity (VO2 max) after a period of sauna bathing (1-3). The underlying causes of the effects lies in the body´s response to the immense heat stress; an activation of the sympathetic nervous system and the hypothalamus- pituitary- adrenal hormonal axis. Activation results in increased plasma levels of ACTH, growth hormone, prolactin, noradrenalin, and beta-endorphin (1,3,4). It has also been shown that insulin sensitivity increases (5).
Increased protein synthesis
Mouse models have shown that that hyperthermic conditions (as in sauna bathing) decrease muscle degradation and increase muscle hypertrophy by increasing net protein synthesis (6-7). Human studies have shown that heat stress induces hypertrophy when simultaneously participating in resistance training, suggesting that inducing heat will have positive effects on strength and hypertrophy (8-9).
How can you then use this to your advantage?
Take 5-20 minute sauna baths for 1-3 sets with cooling sessions in-between (it should feel uncomfortable) several times a week. The sauna should have a temperature of 80-100 degree Celsius and have a humidity of between 10-25% (1,2). Most of the studies are made on radiant-heat saunas (humidity created by pouring water over heated rocks) (3).
Sources:
1. Kukkonen-Harjula Katriina. Health effects and risks of sauna bathing. International Journal of Circumpolar Health 65:3 2006
2. Laukkanen, Tanjaniina. Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events. JAMA Intern Med. 2015;175(4):542-548.
3. Crinnion Walter J. Sauna as a Valuable Clinical Tool for Cardiovascular, Autoimmune, Toxicant- induced and other Chronic Health Problems. Alternative Medicine Review Volume 16, Number
4. Kukkonen-Harjula Katriina. Haemodynamic and hormonal responses to heat exposure in a Finnish sauna bath. Eur J Appl Physiol (1989) 58:543-550
5. Krause Mauricio. Heat shock proteins and heat therapy for type 2 diabetes: pros and cons. Curr Opin Clin Nutr Metab Care 2015, 18:374 – 380
6. Hisashi Naito. Heat stress attenuates skeletal muscle atrophy in hindlimb-unweighted rats. J. Appl. Physiol. 88: 359–363, 2000
7. Selsby J. T. Intermittent hyperthermia enhances skeletal muscle regrowth and attenuates oxidative damage following reloading. J Appl Physiol 102: 1702–1707, 2007.
8. Yoon Sung Jin. Effect of low-intensity resistance training with heat stress on the HSP72, anabolic hormones, muscle size, and strength in elderly women. Aging Clin Exp Res. 10 November 2016.
9. Goto Katsumasa Responses of muscle mass, strength and gene transcripts to long-term heat stress in healthy human subjects. Eur J Appl Physiol (2011) 111:17–27
Article written by @jonasliefke a member of team EBT, third year Medical Student with a Bachelor´s degree in Physical Therapy. www.jonasliefke.com
