Deciphering the Role of Polyphenols in Sports Performance: From Nutritional Genomics to the Gut Microbiota toward Phytonutritional Epigenomics

The individual response to nutrients and non-nutrient molecules can be largely affected by three important biological layers. The gut microbiome can alter the bioavailability of nutrients and other substances, the genome can influence molecule kinetics and dynamics, while the epigenome can modulate or amplify the properties of the genome. Today the use of omic techniques and bioinformatics, allow the construction of individual multilayer networks and thus the identification of personalized strategies that have recently been considered in all medical fields, including sports medicine. The composition of each athlete’s microbiome influences sports performance both directly by acting on energy metabolism and indirectly through the modulation of nutrient or non-nutrient molecule availability that ultimately affects the individual epigenome and the genome. Among non-nutrient molecules polyphenols can potentiate physical performances through different epigenetic mechanisms. Polyphenols interact with the gut microbiota, undergoing extensive metabolism to produce bioactive molecules, which act on transcription factors involved in mitochondrial biogenesis, antioxidant systems, glucose and lipid homeostasis, and DNA repair. This review focuses on polyphenols effects in sports performance considering the individual microbiota, epigenomic asset, and the genomic characteristics of athletes to understand how their supplementation could potentially help to modulate muscle inflammation and improve recovery.

New strategies in sport nutrition to increase exercise performance

Despite over 50 years of research, the field of sports nutrition continues to grow at a rapid rate. Whilst the traditional research focus was one that centred on strategies to maximise competition performance, emerging data in the last decade has demonstrated how both macronutrient and micronutrient availability can play a prominent role in regulating those cell signalling pathways that modulate skeletal muscle adaptations to endurance and resistance training. Nonetheless, in the context of exercise performance, it is clear that carbohydrate (but not fat) still remains king and that carefully chosen ergogenic aids (e.g. caffeine, creatine, sodium bicarbonate, beta-alanine, nitrates) can all promote performance in the correct exercise setting. In relation to exercise training, however, it is now thought that strategic periods of reduced carbohydrate and elevated dietary protein intake may enhance training adaptations whereas high carbohydrate availability and antioxidant supplementation may actually attenuate training adaptation. Emerging evidence also suggests that vitamin D may play a regulatory role in muscle regeneration and subsequent hypertrophy following damaging forms of exercise. Finally, novel compounds (albeit largely examined in rodent models) such as epicatechins, nicotinamide riboside, resveratrol, β-hydroxy β-methylbutyrate, phosphatidic acid and ursolic acid may also promote or attenuate skeletal muscle adaptations to endurance and strength training. When taken together, it is clear that sports nutrition is very much at the heart of the Olympic motto, Citius, Altius, Fortius (faster, higher, stronger).