A recent study conducted in Korea and published in the journal Aging Clinical and Experimental Research examined the muscle-building attribute of heat stress when combined with resistance training. Scientists split subjects into three groups. The first group subjected their legs to warming blankets. The second group did lower-body strength training, and the third group combined the strength training with the heat therapy.
After 12 weeks, the third group experienced greater stimulation of anabolic hormones and improved their muscle strength and hypertrophy significantly greater than the other groups. Interestingly, the one-rep max and IGF-1 levels of all groups improved, but only the subjects who combined the weight training and the heat enjoyed significant muscle growth. Scientists believe that combining resistance training and heat stress stimulates the activation of something called “heat shock protein 72,” leading to greater muscle synthesis.