Broad Spectrum Polyphenol Supplementation from Tart Cherry Extract on Markers of Recovery from Intense Resistance Exercise

Abstract

Background Tart cherry supplementation has been shown to enhance recovery from strenuous exercise due to its antioxidant properties. The majority of these studies used tart cherry juice, with a significant calorie content. The primary purpose of this study was to assess whether powdered tart cherry extract with minimal calorie content reduces oxidative stress and enhances recovery following intense resistance exercise. Methods Thirteen men (mean age: 26.2 ± 5.3 years; height: 184.3 ± 8.2 cm; weight: 92.9 ± 15.6 kg) performed a demanding resistance exercise protocol consisting of 6 sets of 10 repetitions of barbell back squat with 80% 1RM. The protocol was performed once following 7 days of 500 mg of tart cherry extract and once following placebo. Serum protein carbonyl (PC) content, creatine kinase activity (CK) and creatine kinase myocardial band content (CK-MB) were used to assess oxidative stress, skeletal and cardiac muscle damage respectively. Muscle soreness was assessed by visual analog scale. Physical performance was measured by countermovement jump power and handgrip dynamometer strength. Results There was a significant increase in PC in the placebo (PL) condition when compared to the Tart Cherry (TC) condition at Immediate Post (IP) (PL: 0.4 ± 0.3 vs. TC: − 0.4 ± 0.2 nmol∙mg− 1; p < 0.001), 1 h (PL: 0.3 ± 0.3 vs. TC: − 0.7 ± 0.3 nmol∙mg− 1; p < 0.001) and 24 h (PL: 0.1 ± 0.4 vs. TC: − 0.3 ± 0.5 nmol∙mg− 1; p = 0.010). There was a significant increase in CK activity in PL when compared to the TC at IP (PL: 491.1 ± 280 vs. TC: 296.3 ± 178 U∙L− 1; p = 0.008) and 3 h (PL: − 87 ± 123 vs. TC: 43.1 ± 105.3 U∙L− 1; p = 0.006). There was a significant (p = 0.003) increase in CKMB concentration in PL when compared to the TC (PL: 21.6 ± 12.4 vs. TC: − 0.3 ± 11.8 ng∙ml− 1; p = 0.006) at 1 h post. There was a significant increase in handgrip strength in TC when compared to PL (PL: − 2 ± 5.1 vs. TC: 1.7 ± 3 kg; p = 0.017) at 24 h post. Conclusions This study demonstrated that tart cherry extract reduced oxidative stress and markers of muscle and cardiac damage following intense resistance exercise. This occurred along with a prevention of the decrease in handgrip strength seen following the intense exercise protocol, indicating a potential reduction in central fatigue. These benefits were seen with minimal energy intake.

The Effect of a Citrus and Pomegranate Complex on Physical Fitness and Mental Well-Being in Healthy Elderly: A Randomized Placebo-Controlled Trial

“…The values for handgrip strength observed in this study were comparable to normative values of the UK biobank, as well as a cohort from the United States within the same age group (33,34). Only two previous studies have investigated the effects of a polyphenol-rich intervention on handgrip strength, both of which were performed in male adults (35,36). Supplementation with grape juice in male volleyball athletes did not result in improved handgrip strength (35), while a significant improvement in handgrip strength 24 hours after intense resistance exercise was observed in male adults (36).…”

“…Only two previous studies have investigated the effects of a polyphenol-rich intervention on handgrip strength, both of which were performed in male adults (35,36). Supplementation with grape juice in male volleyball athletes did not result in improved handgrip strength (35), while a significant improvement in handgrip strength 24 hours after intense resistance exercise was observed in male adults (36). Similar to our study, several polyphenol-rich intervention studies using different isometric strength tests have observed improvements in recreationally active males and older subjects (37)(38)(39).…”

Tart Cherry Supplement Enhances Skeletal Muscle Glutathione Peroxidase Expression and Functional Recovery after Muscle Damage

“…This study used a double-blind crossover design in which participants completed two trials separated by a 2-wk washout period in line with previous literature (10,15,21,22). The study received ethical approval from the Sport and Health Sciences ethics committee at the University of Exeter and Human Research Ethics committee at the University of Queensland, and all testing conformed to the guidance set out by the Declaration of Helsinki (see additional information for details).…”

Anti‐fatigue properties of the ethanol extract of Moringa oleifera leaves in mice

“…Epidemiological studies have indicated that polyphenol intake is correlated with reduced oxidative stress and improves muscle function following intense resistance exercise. [43][44][45] Therefore, polyphenols play an important role in the improvement of physical performance. Antioxidant activity is crucial in reflecting the biological activity of MLEE.…”