Effects of a Commercial Herbal-Based Formula on Exercise Performance in Cyclists

Abstract

Introduction/Purpose: We examined the effects of a commercially marketed herbal-based formula purported to increase endurance on oxygen consumption (V̇O2) in 17 competitive category III/IV amateur cyclists [mean (SEM) age: 31.1 (1.8) yr; height: 178.5 (1.8) cm; weight: 77.1 (1.6) kg]. Methods: Each cyclist participated in two (pre/post) cycling tests progressing 25 W·4 min-1 starting at 100 W administered in a randomized, placebo-controlled, double-blind fashion. The second trial was performed 14 d after the ingestion of a manufacturer recommended loading phase (4 d × 6 caps·d-1) and a maintenance phase (11 d × 3 caps·d-1). Three treatment capsules contained 1000 mg of Cordyceps sinensis (CS-4) and 300 mg Rhodiola rosea root extract as the primary ingredients; 800 mg of other ingredients included calcium pyruvate, sodium phosphate, potassium phosphate, ribose, and adenosine and 200 mcg of chromium. Results: Using a 2 × 2 ANOVA, we observed no significant treatment effect for any between or within group variables including peak V̇O2 [treatment 4.14 (0.2) L·min-1; placebo 4.10 (0.2) L·min-1], time to exhaustion [treatment 38.47 (1.7) min; placebo 36.95 (1.8) min], peak power output (PO) [treatment 300.00 (12.1) W; placebo 290.63 (12.9) W], or peak heart heart rate. We also observed no differences for any subpeak exercise variable including the PO eliciting 2 mmol·L-1 blood lactate (BLa) [treatment 201.00 (18.1) W; placebo 167.50 (19.2) W] and 4 mmol·L-1 BLa [treatment 235.88 (15.8) W; placebo 244.78 (14.9) W], ventilatory threshold, respiratory compensation point, or V̇O2 L·min-1 and gross efficiency at each stage, Conclusion: A 2-wk ingestion schema of a commercial herbal-based formula is insufficient to elicit positive changes in cycling performance.