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Purpose: This study investigated the effect of menthol (MEN) mouth rinsing (MR) on cycling performance during a modified variable cycle test (M-VCT) in adolescent athletes under hot conditions (31.4 ± 0.9 °C, 23.4 ± 3.7% relative humidity). Methods: Trained adolescent male cyclists (n = 11, 16.7 ± 1.3 years, height 176.6 ± 8.8 cm, body mass 65.8 ± 11.6 kg, maximal oxygen uptake 62.97 ± 7.47 ml·kg⁻¹·min⁻¹) voluntarily completed three trials (familiarization and two experimental) of a 30-min M-VCT, which included five 6-min laps consisting of three 6-s accelerations and three 10-s sprints throughout each lap. In a randomized crossover design, MEN (0.01%) or placebo (PLA) (crystal-light), was swilled for 5 s before the start of each lap (total of 6 MR). Power output, distance (in kilometers), core temperature, heart rate, perceptual exertion, thermal stimulation (thermal comfort and thermal sensation), and blood lactate concentration were recorded. Results: MEN MR significantly improved M-VCT mean power output by 1.81 ± 1.57% compared to PLA (MEN, 177.8 ± 31.4 W; PLA, 174.7 ± 30.5 W, p < .001, 95% confidence interval [1.73, 4.46], d = 1.53). For maximal intermittent sprints, 6- and 10-s mean power output was significantly higher with MEN than PLA (6 s, p = .041, 95% confidence interval [0.73, 27.19], d = 0.71; 10 s, p = .002, 95% confidence interval [11.08, 35.22], d = 1.29). There was no significant difference in core temperature, heart rate, blood lactate concentration, or any perceptual measure between trials (p > .05) despite significantly higher work with MEN. Conclusion: 64% of athletes (7/11) improved M-VCT performance with MEN. The results of this investigation suggest that a MEN MR may improve power output during a sport-specific stochastic cycling task in elite adolescent male cyclists.

This study aimed to determine energy availability (EA) and within-day energy balance (WDEB) in female soccer players during preseason and also explored eating disorder risk and athlete food choice. We hypothesized commonly used indicators of low energy availability (LEA) risk would correlate with measured EA and WDEB variables, and that food choice determinants would differ according to EA. Eleven National Premier League female soccer players participated in this observational cross-sectional study over 3 weeks. Assessment of resting metabolic rate and physique traits, including bone mineral density, was conducted during Weeks 1 or 3. During Week 2, dietary intake, energy expenditure, and continuous monitor-derived glucose were measured for 5 days. EA was calculated daily and WDEB calculated hourly with deficits/surpluses carried continuously. Questionnaires were administered throughout the 3 weeks, including the Athlete Food Choice Questionnaire, the Eating Disorders Screen for Athletes, and the Low Energy Availability in Females Questionnaire. Resting metabolic rate ratio, bone mineral density, Low Energy Availability in Females Questionnaire, and Eating Disorders Screen for Athletes scores were used as indicators of LEA risk. EA averaged 30.7 ± 7.5 kcals·kg fat-free mass⁻¹·day⁻¹. Approximately one-third (36%) of athletes were at risk of an eating disorder, while approximately half (45%) were identified at risk of the female athlete triad via Low Energy Availability in Females Questionnaire, compared with approximately one-third (36%) of athletes identified with EA < 30 kcal·kg fat-free mass⁻¹·day⁻¹. No athlete achieved EA >45 kcal·kg fat-free mass⁻¹·day⁻¹, and no indicator of LEA risk was associated with calculated EA or WDEB. However, overnight glycemic variability was positively correlated with measured EA (r = .722, p = .012).

This study aimed to investigate the effects of caffeine ingestion by chewing gum (GUM_CAF) combined with priming exercise on pulmonary oxygen uptake ( ${\dot{\mathrm{V}}\mathrm{O}}_2$ ) and near-infrared spectroscopy-derived muscle oxygen extraction (HHb + Mb) kinetics during cycling performed in a severe-intensity domain. Fifteen trained cyclists completed four visits: two under a placebo gum (GUM_PLA) and two under GUM_CAF ingestion. Each visit consisted of two square-wave cycling bouts at Δ70 intensity (70% of difference between the ${\dot{\mathrm{V}}\mathrm{O}}_2$ at first ventilatory threshold and ${\dot{\mathrm{V}}\mathrm{O}}_2\text{max}$ ) with duration of 6 min each and 5 min of passive rest between the bouts. The GUM_PLA or GUM_CAF (400 mg) was chewed for 5 min, 12 min before the first Δ70 bout in a randomized double-blind procedure. The fundamental phase and slow component of HHb + Mb and ${\dot{\mathrm{V}}\mathrm{O}}_2$ kinetics were evaluated. For HHb + Mb kinetics, regardless of ingested gum, priming exercise effects occurred on the time constant (GUM_CAF 16.0 ± 4.0 vs. 13.9 ± 2.9 s; GUM_PLA 15.7 ± 6.1 vs. 13.2 ± 2.5 s), amplitude, slow component, time delay, and mean response time parameters (p ≤ .032). For ${\dot{\mathrm{V}}\mathrm{O}}_2$ kinetics, there were significant effects of bouts on the amplitude, slow component, end ${\dot{\mathrm{V}}\mathrm{O}}_2$ , and the gain kinetics parameters (p < .017). Baseline ${\dot{\mathrm{V}}\mathrm{O}}_2$ was higher during GUM_CAF than GUM_PLA (p = .020). No significant effects occurred for the interaction between gum and bout in any parameter of ${\dot{\mathrm{V}}\mathrm{O}}_2$ or HHb + Mb kinetics. Therefore, unlike the priming exercise in severe-intensity exercise, GUM_CAF is not an effective strategy for improving ${\dot{\mathrm{V}}\mathrm{O}}_2$ or HHb + Mb kinetics acceleration.

Background: Several studies have revealed the positive healthy impacts of branched-chain fatty acids (BCFAs). However, most of these studies evaluated the serum BCFAs in humans, or treatment with exogenous BCFAs in animal or in-vitro models and the health impacts of dietary BCFAs have not yet been studied. Due to positive effects of BCFAs in sport, in the current study, we aimed to investigate the association between dietary BCFAs and metabolic and inflammatory parameters among elite and subelite soccer players. Methods: A cross-sectional study was carried out among 335 elite and subelite soccer players (196 male), aged between 20 and 45 years old. Soccer players were enrolled from 32 teams under the directive of The Chinese Football Association. Demographic, anthropometric, and dietary assessments were performed and laboratory measurement including serum lipids, glycemic markers, and high-sensitivity C-reactive protein was measured. Results: Those with the highest dietary BCFAs consumption had higher appetite (p = .009). Also, high consumption of dietary BCFAs was associated with lower diastolic blood pressure (odds ratio: 0.958; confidence interval: 0.918–0.999; p = .046) and low high-sensitivity C-reactive protein concentrations in the third tertile of dietary BCFAs (odds ratio: 0.431; confidence interval: 0.300–0.618; p < .001). No other association between biochemical variables and dietary BCFAs was found. Conclusion: As shown in the current study, higher dietary BCFAs consumption was associated with lower diastolic blood pressure and inflammation. Due to very limited number of studies, further studies are needed to have a better perspective of these associations and their underlying mechanisms.

Objectives: Dietary strategies to improve arachidonic acid:eicosapentaenoic acid (AA:EPA) ratios are of interest due to potential reductions in inflammation and oxidative stress following exercise. The aim of this study was to investigate the impact of a novel dietary intervention, that is, the ingestion of 30 g of dark chocolate, on blood lipid profiles and gut microbiota composition in elite male soccer players. Methods: Professional male soccer players were randomly assigned to the experimental group (DC) provided with 30 g of dark chocolate or to the control group (WC), provided with 30 g of white chocolate, for 30 days. Before and after intervention, blood, fecal sample, and anthropometry data were collected. For each outcome, two-way repeated-measure analysis of variance was used to identify differences between baseline and endpoint (Week 4), considering treatment (dark chocolate, white chocolate) as intersubjects’ factors. Metagenomic analysis was performed following the general guidelines, which relies on the bioBakery computational environment. Results: DC group showed increased plasma polyphenols (from 154.7 ± 18.6 μg gallic acid equivalents/ml to 185.11 ± 57.6 μg gallic acid equivalents/ml, Δ pre vs. post = +30.41 ± 21.50) and significant improvements in lipid profiles: total cholesterol (Δ −32.47 ± 17.18 mg/dl DC vs. Δ −2.84 ± 6.25 mg/dl WC, Time × Treatment interaction p < .001), triglycerides (Δ −6.32 ± 4.96 mg/dl DC vs. Δ −0.42 ± 6.47 mg/dl WC, Time × Treatment interaction p < .001), low-density lipoprotein (Δ −18.42 ± 17.13 mg/dl vs. Δ −2.05 ± 5.19 mg/dl WC, Time × Treatment interaction p < .001), AA/EPA ratio (Δ −5.26 ± 2.35; −54.1% DC vs. Δ −0.47 ± 0.73, −6.41% WC, Time × Treatment interaction p < .001) compared with WC group. In addition, 4 weeks of intervention showed a significant increase in high-density lipoprotein concentration in DC group (Δ + 3.26 ± 4.49 mg/dl DC vs. Δ −0.79 ± 5.12 mg/dl WC). Microbial communities in the DC group maintained a slightly higher microbial stability over time (exhibiting lower within-subject community dissimilarity). Conclusion: Ingesting 30 g of dark chocolate over 4 weeks positively improved AA:EPA ratio and maintained gut microbial stability. Dark chocolate ingestion represents an effective nutritional strategy to improve blood lipid profiles in professional soccer players. What Are the Findings? Ingesting 30 g of dark chocolate for 4 weeks positively influences blood lipid AA: EPA ratio while maintaining gut microbial stability. What This Study Adds? Dietary intake of specific foods such as dark chocolate represents an alternative strategy to support the health and recovery of elite soccer players. What Impact Might This Have on Clinical Practice in the Future? From a clinical and translational perspective, dark chocolate ingestion positively modulates favorable blood lipid profiles and polyunsaturated fatty acid metabolism while maintaining gut microbial stability. Dark chocolate ingestion may be considered as an effective nutritional strategy in elite sport environments during periods of high-intensity training and congested competitions. Further research is required to determine functional outcomes associated with the observed improvements in blood lipid profiles.