The impact of dietary supplement NT-020 with Rhodiola rosea on energy, fatigue, and perceived exertion

Abstract

Purpose: Evaluate the effectiveness of a commercially available nutraceutical product on levels of exercise-related energy, fatigue, and exertion before and after 4 weeks of supplementation. Primary ingredients within the product include a proprietary blend of blueberry extract, green tea extract, L-carnosine, Vitamin D3 (NT-020; 920mg), and Rhodiola rosea, a plant that purports to boost energy and hold antioxidant and anti-inflammatory properties. Methods: Twenty-seven participants (13 females, 14 males, mean BMI = 23, mean age ± SD = 24 + 6 years) completed a baseline assessment of aerobic fitness (mean VO2 peak = 40 mL x kg-1 x min-1) before being randomized into a placebo or supplement group for four weeks. All participants were involved in regular physical activity three or more days per week. Assessment of energy, fatigue, and perceived exertion responses during and immediately following moderately intense cycle ergometry exercise was conducted before and after the 4-week ingestion period during which participants were instructed to maintain existing exercise activities. Results: Data were analyzed by way of repeated measures ANOVA and dependent t-tests to determine the presence of significant differences across time and between the supplement and placebo conditions. Participants receiving the supplement reported: greater levels of energy and lower levels of fatigue during the initial moments after completing the exercise trial (p < 0.05), greater levels of energy at the midpoint of the exercise trial (p < 0.05) but not at the end of the exercise session (p > 0.05), and lower perceived exertion at four of the six measurement points during exercise (p < 0.05). No differences were observed from pre to post intervention within the placebo condition (p > 0.05). Conclusions: Findings indicate that a commercially available supplement marketed to boost energy and reduce fatigue can deliver the purported benefits at least in part. Related findings that supplementation for a 4-week period can allow for equal work at a lower rating of perceived exertion provides further, though limited support that this product may have efficacy.