“This is the first research paper that we know of that studies ashwagandha as an adjuvant to resistance training programs,” said researchers.
A new study published in the Journal of the International Society of Sports Nutrition suggests that KSM-66 brand ashwagandha (Withania somnifera) may improve muscle strength, size, and recovery in adult males engaged in resistance training.
Researchers found that healthy adult males who consumed the ashwagandha root extract in addition to resistance training for eight weeks experienced significantly greater increases in muscle strength and size over a placebo group, and had a significantly greater reduction of markers of exercise-induced muscle damage. The study also found that KSM-66 supplementation may offer a significantly greater increase in testosterone levels and a significantly greater decrease in body fat percentage.
According to KSM-66 supplier Ixoreal Biomed (Los Angeles), the findings are noteworthy for indicating that KSM-66 ashwagandha may “increase the body’s adaptation in response to strength training and serve as a useful adjuvant.”
“While there are other published studies demonstrating the effectiveness of ashwagandha in increasing strength and stamina, this is the first study using a standardized, branded ashwagandha extract and demonstrating significant effects on muscle strength, size, and recovery,” says Kartikeya Baldwa, director of Ixoreal Biomed. “This study also corroborates the findings from a previously published clinical study, showing KSM-66 to be effective in increasing natural testosterone production in men.”
The randomized, double-blind, placebo-controlled study included 57 healthy males aged 18-50 with little previous resistance training experience. Subjects were randomized to consume 300 mg of KSM-66 ashwagandha root extract or a starch placebo twice daily for eight weeks. Both the experimental and control groups underwent resistance training during the eight-week experimental period.
At the outset and conclusion of the trial, subjects were evaluated for muscle strength with a one-repetition maximum (1-RM) load for bench press and leg extension exercises. Researchers evaluated muscle recovery based on serum creatine kinase levels as a marker of exercise-induced muscle injury. Body composition and serum testosterone levels were also used as secondary efficacy measures.
Compared to the placebo group, researchers found that the ashwagandha group experienced a significantly greater increase in muscle strength on the bench-press exercise (26.4 kg for placebo versus 46.0 kg for ashwagandha) and leg-extension exercise (9.8 kg for placebo versus 14.5 kg for ashwagandha). The ashwagandha group also showed a significantly greater muscle size increase at the arms (5.3 cm2 for placebo versus 8.6 cm2 for ashwagandha) and chest (1.4 cm for placebo versus 3.3 cm for ashwagandha).
Additionally, the ashwagandha group also demonstrated a significantly greater reduction of exercise-induced muscle damage as indicated by serum creatine kinase, a significantly greater increase in testosterone levels, and significantly greater decrease in body fat percentage when compared with the placebo group.
“This study reports that ashwagandha supplementation is associated with significant increases in muscle mass and strength and suggests that ashwagandha supplementation may be useful in conjunction with a resistance training program,” concluded the researchers.
Nutritional Outlook Magaine
Wankhede S et al., “Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial,” Journal of the International Society of Sports Nutrition. Published online November 25, 2015.