Effect of an herbal/botanical supplement on recovery from delayed onset muscle soreness: a randomized placebo-controlled trial

Background: We examined the effects of a proprietary herbal/botanical supplement (StemSport, Stemtech, San Clemente, CA.) suggested to increase circulating stem cells, decrease inflammation, and attenuate exercise induced muscle damage on recovery from delayed onset muscle soreness (DOMS). Methods: Sixteen subjects (male = 7, female = 9; age 23.8 +/- 10 years; height 171.9 +/- 10 cm, mass 72.2 +/- 15 kg) were randomized in a crossover, double-blind, placebo controlled trial to receive a placebo or StemSport supplement (6150 mg/day) for 14 days. DOMS was induced on day 7 for both placebo and active conditions in the non-dominant elbow flexor group with repeated eccentric repetitions. Muscle swelling (biceps girth), elbow flexor isometric strength (hand held dynamometer), muscle pain/tenderness (visual analog scale), range of motion (active elbow flexion and extension), and inflammation (hsCRP, IL6, and TNF-alpha) were measured at baseline and at 24 h, 48 h, 72 h, and 168 h (1 week) post eccentric exercise. The crossover washout period was >= 14 days. Results: No significant condition-by-time interactions between placebo and StemSport supplementation were observed with regard to measures of pain (p = 0.59), tenderness (p = 0.71), isometric strength (p = 0.32), elbow flexion (p = 0.45), muscle swelling (p = 0.90), or inflammation (p > 0.90). Decrements in elbow extension range of motion 48 h post-exercise were less after StemSport supplementation (Delta elbow extension 48 h post; StemSport, -2.0 deg; placebo, -10 deg; p = 0.003). Conclusions: These data suggest that compared to placebo, StemSport supplementation does not improve outcome measures related to muscle recovery after acute upper-arm induced DOMS.