Elite athletes are always looking for the next cutting edge training or nutrition strategy to boost their performance. High level cyclists have begun using something that many of us might associate with wrestlers trying to cut weight—the sauna.
Various studies show that heat acclimation can produce physiological benefits that transfer to increased athletic performance. Below we'll enumerate other athletic benefits of heat therapy and how you can implement it to improve your performance.
What is Heat Therapy?
A concept popularized by Dr. Rhonda Patrick, heat therapy, or hyperthermic conditioning, is the practice of heat acclimation independent of working out, via the use of things like the sauna. Heat acclimation is the physiological adaptation to heat stress that has potential performance-enhancing benefits.
When we exercise, our core temperature rises, coinciding with cardiovascular strain and exhaustion. Acclimating one's body to elevations in core temperature better equips us to manage this stress during exercise.
The Benefits of Heat Therapy
Acclimation to heat exposure results in beneficial adaptations like increased plasma volume, increased red blood cell count and increased blood flow to the heart and skeletal muscles. These adaptations are associated with improvements in conditioning and performance. A more efficient aerobic system means that one can train harder and for longer periods of time.
Three weeks of post-exercise sauna bathing produced significant enhancement of endurance running performance. Sauna bathing increased run time to exhaustion by 32%. Plasma and red cell volume increased by 7.1% and 3.5%, respectively, after sauna exposure relative to a control group. Change in performance had high correlations with change in plasma volume and total blood volume.
Sauna bathing following normal training has been shown to largely expand plasma volume in well-trained cyclists after just four exposures.
Heat exposure also has anabolic benefits, which seem to be associated with increased lean muscle mass and strength, including increased release of human growth hormone (HGH) and triggering of heat shock proteins (HSPs). The activation of HGH and HSPs contributes to an overall positive protein balance by promoting protein synthesis while inhibiting protein degradation. An overall positive protein balance translates to the ability to grow (and maintain) lean muscle mass. HSPs also repair damaged proteins so that they maintain their proper structure.
A group of researchers studied the effects of wrapping a blanket around the leg of 8 subjects so that the heat penetrated their muscles. The treatment lasted 10 weeks. For four days a week, the subjects sat for 8 hours with a blanket around their leg muscles. They had a normal average temperature of 34.9 degrees Celsius, but the blanket raised it to 38.3 degrees Celsius. The heat therapy made the leg muscles bigger despite a lack of training. And the treatment also made some leg muscles stronger. During a test of the leg extensors, the max isometric torque increased by 5.88 percent.
In a study financed by the South Korean government, researchers divided women into three groups. The first group was exposed to a heating sheet on their upper legs three times a week for eight consecutive hours during the 12 weeks the experiment lasted, causing a rise in muscle temperature from 35 to 39 degrees. Another group trained their upper-leg muscles on a leg extension machine three times a week. These women did 3 sets with 40% of a weight at which they could manage 1 rep. A third group engaged in resistance training and heat therapy. The concentration of growth hormone and IGF-1 in the blood of all three groups increased significantly, but only participants who combined both treatments built up significantly more muscle mass.
Recovery and Health Benefits
In human and animal studies, the results of heat exposure are impressive for potential recovery and health benefits. Animal studies have shown that heat exposure can increase rates of skeletal muscle regrowth after injury, provide powerful antioxidant benefits, and improve metabolic status (improved insulin sensitivity and favorable cholesterol levels). In humans, heat exposure has been associated with lowered risk of cognitive decline.
A cohort study was conducted on 2,135 healthy men between 42 and 60 years of age between 1984 and 1989. A follow-up was conducted 20 years (20.7 median) later, and 204 and 123 diagnosed cases of dementia and Alzheimer's disease, respectively, were recorded. After adjusting for factors such as age, alcohol consumption, body mass index, blood pressure, smoking, Type 2 diabetes, RHR and LDL cholesterol, the study found that increased sauna exposure resulted in lowered risks of dementia and Alzheimer's. Interestingly, increased sauna exposure resulted in greater amounts of decreased risk. The men who took saunas 4-7 times a week were at lower risk than the men who took fewer saunas per week.
How to Apply Heat Therapy
A few things to consider regarding using heat exposure:
- It's crucial that to take precautions and consult with a health care provider first, before considering heat exposure, since elevated core temperatures and heart rates can be potentially dangerous.
- In most of the studies, heat exposure involved moderate time periods; more is not always better. The exposure ranged from 15 to 30 minutes.
- If one is unaccustomed to heat exposure, it would be wise to start slow and gradually build up their conditioning, like they would for any other form of training
- Because heat exposure causes one to sweat greater amounts of fluid, having an electrolyte-rich post workout/heat conditioning drink available would be a wise choice.
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