Biomarkers of post-match recovery in semi-professional and professional football (soccer).

High-level football (soccer) players face intense physical demands that result in acute and residual fatigue, impairing their physical performance in subsequent matches. Further, top-class players are frequently exposed to match-congested periods where sufficient recovery times are not achievable. To evaluate training and recovery strategies, the monitoring of players' recovery profiles is crucial. Along with performance and neuro-mechanical impairments, match-induced fatigue causes metabolic disturbances denoted by changes in chemical analytes that can be quantified in different body fluids such as blood, saliva, and urine, thus acting as biomarkers. The monitoring of these molecules might supplement performance, neuromuscular and cognitive measurements to guide coaches and trainers during the recovery period. The present narrative review aims to comprehensively review the scientific literature on biomarkers of post-match recovery in semi-professional and professional football players as well as provide an outlook on the role that metabolomic studies might play in this field of research. Overall, no single gold-standard biomarker of match-induced fatigue exists, and a range of metabolites are available to assess different aspects of post-match recovery. The use of biomarker panels might be suitable to simultaneously monitoring these broad physiological processes, yet further research on fluctuations of different analytes throughout post-match recovery is warranted. Although important efforts have been made to address the high interindividual heterogeneity of available markers, limitations inherent to these markers might compromise the information they provide to guide recovery protocols. Further research on metabolomics might benefit from evaluating the long-term recovery period from a high-level football match to shed light upon new biomarkers of post-match recovery.

Compositional Aspects of Beverages Designed to Promote Hydration Before, During, and After Exercise: Concepts Revisited.

Hypohydration can impair aerobic performance and deteriorate cognitive function during exercise. To minimize hypohydration, athletes are recommended to commence exercise at least euhydrated, ingest fluids containing sodium during long-duration and/or high-intensity exercise to prevent body mass loss over 2% and maintain elevated plasma osmolality, and rapidly restore and retain fluid and electrolyte homeostasis before a second exercise session. To achieve these goals, the compositions of the fluids consumed are key; however, it remains unclear what can be considered an optimal formulation for a hydration beverage in different settings. While carbohydrate-electrolyte solutions such as sports drinks have been extensively explored as a source of carbohydrates to meet fuel demands during intense and long-duration exercise, these formulas might not be ideal in situations where fluid and electrolyte balance is impaired, such as practicing exercise in the heat. Alternately, hypotonic compositions consisting of moderate to high levels of electrolytes (i.e., ≥45 mmol/L), mainly sodium, combined with low amounts of carbohydrates (i.e., <6%) might be useful to accelerate intestinal water absorption, maintain plasma volume and osmolality during exercise, and improve fluid retention during recovery. Future studies should compare hypotonic formulas and sports drinks in different exercise settings, evaluating different levels of sodium and/or other electrolytes, blends of carbohydrates, and novel ingredients for addressing hydration and rehydration before, during, and after exercise.

The effect of a low-fat spread with added plant sterols on vascular function markers: results of the Investigating Vascular Function Effects of Plant Sterols (INVEST) study.

BACKGROUND: Plant sterols (PSs) lower LDL cholesterol, an established risk factor for coronary artery disease (CAD). No direct evidence is available supporting a reduced risk of CAD for foods with added PSs. Endothelial dysfunction is seen as an early indicator of atherosclerotic damage. OBJECTIVES: This study was primarily designed to investigate the effect of a low-fat spread with added PSs on brachial artery endothelial function as measured by flow-mediated dilation (FMD). Second, effects on arterial stiffness, blood pressure, serum lipids, and plasma PS concentrations were investigated. We hypothesized that PSs would not worsen FMD but would rather modestly improve FMD. DESIGN: This study had a double-blind, randomized, placebo-controlled, parallel design. After a 4-wk run-in period, 240 hypercholesterolemic but otherwise healthy men and women consumed 20 g/d of low-fat spread without (control) or with added PSs (3 g/d) during 12 wk. Pre- and postintervention, vascular function measurements and blood sampling were performed. RESULTS: In total, 232 participants completed the study period. For the primary endpoint FMD, 199 participants were included in the statistical analysis. PS intake did not affect FMD (+0.01 percentage points; 95% CI: -0.73, 0.75) compared with control. Measures of arterial stiffness (pulse wave velocity and augmentation index) and blood pressure were also not significantly changed compared with control. After PS intervention, LDL cholesterol significantly decreased on average by 0.26 mmol/L (95% CI: -0.40, -0.12) or 6.7% compared with control. Plasma sitosterol and campesterol concentrations significantly increased in the PS group up to on average 11.5 µmol/L and 13.9 µmol/L (expressed as geometric means), respectively. CONCLUSIONS: The intake of a low-fat spread with added PSs neither improved nor worsened FMD or other vascular function markers in hypercholesterolemic men and women. As expected, serum LDL cholesterol decreased, whereas plasma PSs increased after PS intake. This study was registered at clinicaltrials.gov as NCT01803178.