Examining the effect ofWithania somniferasupplementation on muscle strength and recovery: a randomized controlled trial

Abstract

BackgroundWithania somnifera (ashwagandha) is a prominent herb in Ayurveda. This study was conducted to examine the possible effects of ashwagandha root extract consumption on muscle mass and strength in healthy young men engaged in resistance training.MethodsIn this 8-week, randomized, prospective, double-blind, placebo-controlled clinical study, 57 young male subjects (18–50 years old) with little experience in resistance training were randomized into treatment (29 subjects) and placebo (28 subjects) groups. Subjects in the treatment group consumed 300 mg of ashwagandha root extract twice daily, while the control group consumed starch placebos. Following baseline measurements, both groups of subjects underwent resistance training for 8 weeks and measurements were repeated at the end of week 8. The primary efficacy measure was muscle strength. The secondary efficacy measures were muscle size, body composition, serum testosterone levels and muscle recovery. Muscle strength was evaluated using the 1-RM load for the bench press and leg extension exercises. Muscle recovery was evaluated by using serum creatine kinase level as a marker of muscle injury from the effects of exercise.ResultsCompared to the placebo subjects, the group treated with ashwagandha had significantly greater increases in muscle strength on the bench-press exercise (Placebo: 26.4 kg, 95 % CI, 19.5, 33.3 vs. Ashwagandha: 46.0 kg, 95 % CI 36.6, 55.5; p = 0.001) and the leg-extension exercise (Placebo: 9.8 kg, 95 % CI, 7.2,12.3 vs. Ashwagandha: 14.5 kg, 95 % CI, 10.8,18.2; p = 0.04), and significantly greater muscle size increase at the arms (Placebo: 5.3 cm2, 95 % CI, 3.3,7.2 vs. Ashwagandha: 8.6 cm2, 95 % CI, 6.9,10.8; p = 0.01) and chest (Placebo: 1.4 cm, 95 % CI, 0.8, 2.0 vs. Ashwagandha: 3.3 cm, 95 % CI, 2.6, 4.1; p < 0.001). Compared to the placebo subjects, the subjects receiving ashwagandha also had significantly greater reduction of exercise-induced muscle damage as indicated by the stabilization of serum creatine kinase (Placebo: 1307.5 U/L, 95 % CI, 1202.8, 1412.1, vs. Ashwagandha: 1462.6 U/L, 95 % CI, 1366.2, 1559.1; p = 0.03), significantly greater increase in testosterone level (Placebo: 18.0 ng/dL, 95 % CI, -15.8, 51.8 vs. Ashwagandha: 96.2 ng/dL, 95 % CI, 54.7, 137.5; p = 0.004), and a significantly greater decrease in body fat percentage (Placebo: 1.5 %, 95 % CI, 0.4 %, 2.6 % vs. Ashwagandha: 3.5 %, 95 % CI, 2.0 %, 4.9 %; p = 0.03).ConclusionThis 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.

Effects of lemon verbena extract (Recoverben®) supplementation on muscle strength and recovery after exhaustive exercise: a randomized, placebo-controlled trial

“…It is possible that the exhaustive exercise protocol used in our study was not intense and/or long enough to elicit meaningful changes in IL-6 that could have been effected by lemon verbena supplementation. Similar results were found in other human studies investigating natural ingredients for effects of muscle strength and muscle damage, such as ashwagandha extract [ 47 ], curcumin [ 48 ], pomegranate extract [ 10 ], and blueberry [ 2 ]. These natural ingredients are high in polyphenols, a trait shared by lemon verbena.…”

Efficacy and Safety of Ashwagandha (Withania somnifera) Root Extract in Insomnia and Anxiety: A Double-blind, Randomized, Placebo-controlled Study

“…Clinical studies conducted in various conditions suggest that Ashwagandha root extract improves sexual performances in both males and females, aids in reducing and managing stress and anxiety, improves memory and cognition in healthy adults and patients with bipolar disorder [16][17][18][19][20]. This multipurpose herb also increases muscle strength, muscle size and supports in muscle recovery [21].…”

Efficacy and Tolerability of Ashwagandha Root Extract in the Elderly for Improvement of General Well-being and Sleep: A Prospective, Randomized, Double-blind, Placebo-controlled Study

“…Several clinical studies have proven the efficacy, tolerability, and safety of Ashwagandha's use in various contexts. The root extract of Ashwagandha was found effective in enhancing cardiorespiratory endurance, improving muscle strength and recovery, and effective in general bodyweight management when compared to the respective placebo [24][25][26]. Apart from the contribution in general well-being, W. somnifera root extract also helps in improving sexual function in both men and women [6,27].…”