Body Building Science: Thermotherapy for Ultimate Muscle Recuperation!

Saunas and hot tubs have been touted for years as a way rejuvenate the body. Sauna sessions or thermal heat used to facilitate sweating, but you sweat in the gym. Do you really need a sauna? For most bodybuilders, saunas and hot tubs are things we know we should incorporate into our workout program, but just don't incorporate them as much as we should.

Health: Benefits of Thermal Therapy
When researching the literature on the recuperative effect of thermal therapy generated by hot tubs and saunas, I was amazed at how the therapeutic effect could enhance muscle recuperation in men. Studies examining the use of saunas found that they:
-Reduce levels of stress hormones adrenalin and noradrenalin, and increase the pleasure and well-being hormone beta-endorphin.¹
-Increase testosterone and growth hormone (GH) in men.
-Reduce the inflammatory mediator prostaglandin F2-alpha, and protect against oxidative stress and free radical damage.
-Regular saunas, when combined with exercise therapy, can efficiently clear organic chemicals, solvents, drugs, pharmaceuticals, and even PCBs and heavy metal from the body. Use moderation when spending time in a sauna; and too much time there can cause an exacerbated stress response.

Can Cranking Up the Heat Make You Bigger?
In a recent study in Orthopaedic Science, researchers reported that muscles of animals exposed to heat stress-stimulated increases in heat shock proteins not only caused the activation of satellite cells, but also increased protein synthesis during the regeneration of injured skeletal muscle. Skeletal muscle stem cells are responsible for the repair and hypertrophy of skeletal muscle. It was strongly suggested by the researchers that the application of heat to injured or damaged muscle may facilitate recovery and enhanced satellite cell activation, leading to enhanced muscle mass.

Want more? In the Journal of Applied Physiology, researchers reported that intermittent heat application (30 minutes on alternating days) to the muscles of rats enhanced muscle hypertrophy. You might want to go steal grandma's heating pad after reading these research papers. Heat shock proteins were previously shown to increase muscle protein synthesis and increase muscle mass. In fact, a single bout of heat stress has been demonstrated to increase muscle mass and protein synthesis. Heat shock proteins are stimulated by many factors. They were originally found to increase with the application of heat- hence, 'heat shock proteins.'

Thermal Therapy Boosts Nitric Oxide Production
New research elucidates why thermal therapy such as saunas and hot tubs may be so beneficial to bodybuilders- thermal therapy increases nitric oxide production. Several studies have reported the importance of nitric oxide for muscle recuperation and satellite cell activity. Thermal therapy is currently being used to treat various cardiovascular disease symptoms. In subjects with cardiovascular risk factors who underwent daily sauna treatment for two weeks (15 minutes of 60°C infrared sauna followed by 30 minutes covered with blankets), endothelium-dependent vasodilatation increased significantly- meaning more blood flow to the tissues.

Thermal therapy may also help to reduce blood pressure through the enhancement of nitric oxide production. In a series of investigations with moderately-hypertensive patients, twice-weekly sauna bathing for three months was associated with significant reduction in resting systolic and resting diastolic pressure, averaging 20-23 mmHg and 14-18 mmHg, respectively. These reductions in blood pressure were at least as large as those seen in control groups asked to run twice weekly. This means that sitting in the sauna is going to facilitate the production of nitric oxide, which may enhance muscle recuperation.

Thermal Therapy May Increase Insulin Sensitivity to the Same Extent as Exercise
Being insulin-sensitive means that cells are highly responsive to the actions of insulin, which is a good thing. A previous study reported that fish oils, which enhance insulin sensitivity, led to increased muscle mass. The study found that after five weeks, animals with the marine omega-3 diet showed increased sensitivity to insulin, which improved protein metabolism. Animals fed the marine omega-3 diet used twice the amount of amino acids to synthesize proteins, especially in muscle.

New studies suggest that thermal therapy may enhance insulin sensitivity as well as exercise. Sauna therapy resembles exercise training in that it induces a temporary increase in cardiac output (amount of blood produced by the heart per minute) and workload.² Some doctors are starting to use saunas as a way to reap the health benefits of exercise in older adults who can't handle exercise.

In individuals too physically impaired to achieve effective aerobic training, regular thermal therapy might be a feasible alternative, providing somewhat similar benefits for vascular health- as suggested by Tei and colleagues.³ Granted, there is little reason to suspect that thermal therapy would provide the weight-control benefits associated with aerobic training. Surprisingly, however, Tei reports that obese subjects tend to lose body fat during several weeks of daily sauna treatment. Whether this observation can be replicated in well-controlled trials remains to be seen. It seems that sauna/hot tub therapy may not only be relaxing, but may enhance nitric oxide (NO) production which can enhance muscle recuperation. A decrease in NO production with aging may be a contributing factor in the decrease of muscle mass with aging.

Previous research has shown that blunting production of NO decreases muscle hypertrophy during muscle overload. Other researchers reported that NO is a primary signal for satellite cell activation. NO is an important regulator of hepatocyte growth factor (HGF), which is a cytokine with various cellular functions on muscle. Specific to skeletal muscle hypertrophy, HGF activates satellite cells and may be responsible for causing satellite cells to migrate to the injured area. A previous research study reported that stretching a muscle induced hypertrophy via release of HGF; the researchers found that the release of HGF was dependent on NO concentrations. Getting into the sauna or hot tub may be one therapeutic means of recuperation from intense exercise that bodybuilders can benefit from.

Sources:

1. Vescovi PP, Coiro V, Volpi R, Giannini A, Passeri M (1992). Hyperthermia in sauna is unable to increase the plasma levels of ACTH/cortisol, beta-endorphin and prolactin in cocaine addicts. J Endocrinol Invest,
15 (9): 671-5

2. Vuori I. Sauna bather's circulation. Annu Clin Res, 1988; 20:249-56.

3. Biro S, Masuda A, KiharaT,Tei C. Clinical implications of thermal therapy in lifestyle-related diseases. Exp Biol Med. (Maywood) 2003; 228: 1245-9