Polyphenols and performance: Is it worth a try?
By Karen Keane, PhD SENr
Herbs, spices, teas, wines, fruits, barks, roots, leaves and plants rich in phytochemicals have been used for years to treat and cure several ailments. As early as 668 BC, the ancient Greeks reportedly used mushrooms, dried figs and various wine concoctions to enhance their sporting performance in the Olympics1.
Polyphenols are a sub-group of plant phytochemicals. They are defined as having molecular weights ranging from 500-4000 (Da) and possessing between 12-16 phenolic groups with two or more aromatic rings attached. Currently ~10,000 compounds meet this definition. They have been categorised into smaller and more appropriate sub-groups including phenolic acids, flavonoids, stilbenes and lignans (see Figure 1).
Figure 1. Main sub-groups of polyphenols and examples of dietary sources (Created with BioRender).
Polyphenols exhibit a broad range of physiological benefits that include, but are not limited to, antioxidant (AOX) and anti-inflammatory properties. Hence, polyphenol supplementation in exercise science has gained momentum in recent years, with particular interest in polyphenols derived from fruits. A growing body of evidence suggests that polyphenol supplementation enhances restoration of muscle function and reduces inflammation, oxidative stress and muscle soreness after intensive exercise2. Although the potential benefits of polyphenols in expediting exercise recovery have been widely demonstrated, the debate continues as to whether polyphenol supplementation can improve exercise performance. Many authors have noted that during highly intense exercise, an athlete’s capacity to utilize oxygen is a major factor in determining his or her performance. During intense aerobic exercise (with dramatic increases in oxygen consumption), production of free radicals can exceed the intrinsic AOX defence capacity, leading to both muscle fatigue and oxidative stress in the circulatory system, which is responsible for delivery of oxygen. Therefore, unsurprisingly AOX supplements, specifically polyphenol-containing supplements have received a lot of attention with regards to improving exercise performance. The following section will provide a brief synopsis of the short- and longer-term effects of fruit derived polyphenols on exercise performance.
References
- Moffatt AC. History of doping in sport. Sport and Exercise Medicine for Pharmacists, 2006; 219.
- Bowtell J, Kelly V. Fruit-derived polyphenol supplementation for athlete recovery and performance. Sports Medicine, 2019; 49(Supplement 1), pp. 3-23.
