driven by another major constituent—its numerous polyphenols from the ellagitannin subclass. Polyphenols are a group of antioxidants that prevent the normally frequent degradation of NO by reactive oxygen species (ROS), thereby promoting its longevity in the bloodstream ( Ignarro et al., 2006 ; Peri et
Emma M. Crum, Matthew J. Barnes and Stephen R. Stannard
Jason P. Brandenburg and Luisa V. Giles
( Davison et al., 2012 ). Recently, research on antioxidant supplementation has explored the effects of functional foods ( Levers et al., 2016 ; Morgan et al., 2019 ); foods with an elevated content of compounds associated with health benefits. Polyphenols, one such compound, are antioxidants found in
Jae-Keun Oh, Young-Oh Shin, Jin-Ho Yoon, Seong Ho Kim, Hyeon-Cheol Shin and Hye Jeong Hwang
Ecklonia cava polyphenol (ECP) is a potent antioxidant and procirculatory agent that may contribute to improvement of endurance performance during highly intense exercise. This study evaluated the acute effect of an ECP-supplemented drink against a placebo on maximum endurance capacity and related physiological parameters. Twenty men 18–23 yr old volunteered as participants. Each performed 2 randomized trials with a 1-week interval between them. One trial was with ECP and the other with a placebo drink. Participants in this randomized, placebo-controlled, crossover design ingested either a placebo or ECP drink 30 min before each exercise trial. Time to exhaustion, VO2max, and postexercise blood glucose and lactate levels were evaluated. ECP supplementation increased time to exhaustion (2.39 min) compared with placebo. This result was accompanied by a 6.5% higher mean VO2max in the ECP group, although the difference was not statistically significant. The blood glucose level in the ECP group at 3 min after exhaustive exercise was significantly higher than that of the placebo group (+ 9.9%). The postexercise blood lactate levels in the ECP group showed a decreasing trend compared with placebo, but it was nonsignificant. This study was not able to determine any physiological mechanisms behind the improved endurance performance, but, based on these results, it is speculated that the ECP supplementation may have contributed to enhanced oxidation of glucose and less production of lactate during intense exercise, possibly by its free-radical-scavenging and procirculatory activities. However, careful verification is required to elucidate the correct mechanism.
Ewa Jówko, Jaroslaw Sacharuk, Bozena Balasinska, Jacek Wilczak, Malgorzata Charmas, Piotr Ostaszewski and Robert Charmas
To evaluate the effect of acute ingestion of green tea polyphenols (GTP) on blood markers of oxidative stress and muscle damage in soccer players exposed to intense exercise.
This randomized, double-blinded study was conducted on 16 players during a general preparation period, when all athletes participated in a strength-training program focused on the development of strength endurance. After ingestion of a single dose of GTP (640 mg) or placebo, all athletes performed an intense muscle-endurance test consisting of 3 sets of 2 strength exercises (bench press, back squat) performed to exhaustion, with a load at 60% 1-repetition maximum and 1-min rests between sets. Blood samples were collected preexercise, 5 min after the muscle-endurance test, and after 24 hr of recovery. Blood plasma was analyzed for the concentrations of thiobarbituric acid–reacting substances (TBARS), uric acid (UA), total catechins, total antioxidant status (TAS), and activity of creatine kinase (CK); at the same time, erythrocytes were assayed for the activity of superoxide dismutase (SOD).
In both groups, plasma TBARS, UA, and TAS increased significantly postexercise and remained elevated after a 24-hr recovery period. SOD activity in erythrocytes did not change significantly in response to the muscle-endurance test, whereas in both groups plasma CK activity increased significantly after 24 hr of recovery. Acute intake of GTP cased a slight but significant increase in total plasma catechins. However, GTP was found not to exert a significant effect on measured parameters.
Acute ingestion of GTP (640 mg) does not attenuate exercise-induced oxidative stress and muscle damage.
Romain Meeusen and Lieselot Decroix
glucose Giles et al. ( 2012 ) Caffeine is responsible + Omega-3 fatty acids No evidence No evidence Polyphenols >7 days (meta-analysis) Somerville et al. ( 2017 ) + Review Vauzour ( 2012 ) ↑ regional perfusion; ↓ oxidative stress + Quercetin >7 days 764 mg/day (meta-analysis) Somerville et
David B. Pyne, Evert A. Verhagen and Margo Mountjoy
In this review, we outline key principles for prevention of injury and illness in aquatic sports, detail the epidemiology of injury and illness in aquatic athletes at major international competitions and in training, and examine the relevant scientific evidence on nutrients for reducing the risk of illness and injury. Aquatic athletes are encouraged to consume a well-planned diet with sufficient calories, macronutrients (particularly carbohydrate and protein), and micronutrients (particularly iron, zinc, and vitamins A, D, E, B6, and B12) to maintain health and performance. Ingesting carbohydrate via sports drinks, gels, or sports foods during prolonged training sessions is beneficial in maintaining energy availability. Studies of foods or supplements containing plant polyphenols and selected strains of probiotic species are promising, but further research is required. In terms of injury, intake of vitamin D, protein, and total caloric intake, in combination with treatment and resistance training, promotes recovery back to full health and training.
Judith Allgrove, Emily Farrell, Michael Gleeson, Gary Williamson and Karen Cooper
This study investigated the effects of regular consumption of dark chocolate (DC), rich in cocoa polyphenols, on plasma metabolites, hormones, and markers of oxidative stress after prolonged exhaustive exercise. Twenty active men cycled at 60% maximal oxygen uptake (VO2max) for 1.5 hr, with the intensity increased to 90% VO2max for a 30-s period every 10 min, followed by a ride to exhaustion at 90% VO2max. In the 2 wk before exercise participants consumed 40 g of DC or an isocarbohydrate-fat control cocoa liquor–free chocolate (CON) twice daily and once 2 hr before exercise in a randomized, counterbalanced, crossover design. Venous blood samples were taken immediately before exercise, postexercise (fixed duration), postexhaustion, and after 1 hr of recovery. F2-isoprostanes were significantly lower (post hoc tests: p < .001) at exhaustion and after 1 hr of recovery with DC. Oxidized low-density lipoproteins were significantly lower with DC (p < .001) both before and after exercise and at exhaustion. DC was also associated with ~21% greater rises in free fatty acids during exercise (main effect: p < .05). Changes in circulating glucose, insulin, glucagon, cortisol, and interleukin (IL)-6, IL-10, and IL-1ra were unaffected by treatment. Time to exhaustion at 90% VO2max was not significantly different between trials (398 ± 204 and 374 ± 194 s for DC and CON, respectively). These results suggest that regular DC intake is associated with reduced oxidative-stress markers and increased mobilization of free fatty acids after exercise but has no observed effect on exercise performance.
Will Abbott, Callum Brashill, Adam Brett and Tom Clifford
. 11 Moreover, a recent commentary suggested that its use is widespread in the sporting population. 11 TCJ, which is rich in flavonoids—a class of polyphenols known for their anti-inflammatory effects 11 , 12 —has, on a relatively consistent basis, been shown to attenuate systemic inflammation and
David C. Nieman, Giuseppe Valacchi, Laurel M. Wentz, Francesca Ferrara, Alessandra Pecorelli, Brittany Woodby, Camila A. Sakaguchi and Andrew Simonson
studies with a variety of participants, including athletes ( Castro et al., 2017 ; Li et al., 2016 ). Polyphenol intake is a potential countermeasure to exercise-induced physiological stress ( Bermon et al., 2017 ; Nieman et al., 2013 ). Polyphenol metabolism is complex because nearly all that is
Ahmed Ismaeel, Michael Holmes, Evlampia Papoutsi, Lynn Panton and Panagiotis Koutakis
were all similar between groups ( Furlong et al., 2014 ). Likewise, a study investigating the effect of a polyphenol blend consisting of aqueous tea extracts on adaptations to RT included 40 untrained men (aged 18–31 years) who completed a 6-week RT program consisting of three sets of 10 repetitions at