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Effects of chronic betaine supplementation on performance in professional young soccer players during a competitive season: a double blind, randomized, placebo-controlled trial.
Nobari, H, Cholewa, JM, Castillo-Rodríguez, A, Kargarfard, M, Pérez-Gómez, J
Journal of the International Society of Sports Nutrition. 2021;(1):67
Abstract
OBJECTIVE Various nutritional strategies are adopted for athletes to maintain and to improve performance during the competition season. Betaine may enhance performance during a competitive season by increasing the testosterone to cortisol ratio and reducing systemic inflammation. The aim of this study was to investigate the effect of betaine supplementation on the bio-motor abilities in young professional soccer players. METHODS Twenty-nine young professional soccer players (age, 15.5±0.3 years) were matched by position and randomly assigned to one of two groups for 14 weeks: betaine (BG, 2 g/day; n=14) or placebo (PG n=15). Diet was standardized by a nutritionist, and measures of muscular power (countermovement jump: CMJ), change of direction: modified 5-0-5), acceleration (10 m sprint), sprint performance (30 m sprint time: SpT), muscular strength (leg press and bench press one repetition maximum: 1-RM), repeated sprint ability (running-based anaerobic sprint test: RAST), and aerobic capacity (30-15 intermittent fitness test) were assessed in the pre (P1), mid (P2) and post (P3) season over the course of 5 days. All subjects participated in one soccer match and five training sessions per week. RESULTS Significant (p < 0.05) group x time interactions were found for maximal oxygen uptake (VO2max), anaerobic peak power, and muscular strength favoring BG at P2 and P3 compared to P1. There were meaningful (p < 0.05) group x time interactions for CMJ, SpT, and peak power during the RAST that favored the BG. CONCLUSIONS 14-week of betaine supplementation increased predicted 1-RM, VO2max, and repeated sprint ability performance in youth professional soccer players. Betaine supplementation seems to be a useful nutritional strategy to improve and to maintain performance during a competitive soccer season.
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Correlation between strength and skin temperature asymmetries in the lower limbs of Brazilian elite soccer players before and after a competitive season.
Rodrigues Júnior, JL, Duarte, W, Falqueto, H, Andrade, AGP, Morandi, RF, Albuquerque, MR, de Assis, MG, Serpa, TKF, Pimenta, EM
Journal of thermal biology. 2021;:102919
Abstract
This study aimed to investigate the correlation between strength and skin temperature (Tsk) asymmetries in the lower limbs of elite soccer players before and after a competitive season. The sample (n = 20) was composed of elite male soccer players. Strength asymmetry and Tsk asymmetry was measured through the countermovement jump (CMJ) test and infrared thermography, respectively. Asymmetries were quantified using the symmetry angle (SA) equation. A strong correlation was found between the SA of rate of force development (RFD) and the SA of Tsk before (baseline) (r = 0.7; r2 = 0.43; p = 0.03) and after (r = 0.6; r2 = 0.42; p = 0.04) the competitive season. Moreover, after the competitive season there were significant decreases in Peak force (p < 0.018), Impulse (p < 0.04), RFD (p = 0.0001) and CMJ height (p = 0.05), and significant increases in Tsk (p < 0.03), C-reactive protein (p = 0.03), Creatine kinase (p = 0.0001) and Cortisol (p = 0.04), even after a 3-day rest interval (no training). These results suggest that the CMJ test can be combined with infrared thermography for monitoring strength asymmetry and contribute to the prevention of muscle injuries.
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Effects of high-carbohydrate versus mixed-macronutrient meals on female soccer physiology and performance.
Wynne, JL, Ehlert, AM, Wilson, PB
European journal of applied physiology. 2021;(4):1125-1134
Abstract
PURPOSE Athletes are often told to minimize intakes of fiber, fat, and protein in pre-competition meals to avoid gut distress, but this guidance is based on scant direct evidence. This study evaluated the physiological and perceptual effects of pre-competition mixed-macronutrient (MM) and high-carbohydrate (HCHO) meals in collegiate female soccer players. METHODS Fifteen players participated in this randomized, investigator-blinded, crossover study involving two ~ 1000-kcal meals (HCHO and MM) consumed 4 h prior to 70-min scrimmages. Assessments included global positioning system (GPS) tracking, heart rate (HR), perceived exertion (RPE), ratings of fatigue (ROF), gut symptoms, and perceptions of satiety, hunger, and fullness. Differences between conditions for HR, RPE, ROF, and gut symptoms were evaluated with Wilcoxon signed-rank tests. GPS data and hunger, satiety, and fullness scores were compared using within-subjects repeated measures ANOVAs. RESULTS No statistically significant differences were found between the conditions at any time point for HR, RPE, ROF, or gut symptoms. Significant time effects were found for two GPS variables (total distance covered and high-speed running), indicating that participants covered less distance during the second half of the scrimmages in comparison to the first half. However, there were no significant condition or condition × time interactions for GPS data. Finally, there were no condition or condition × time interactions for hunger, fullness, and satiety, though significant time effects were observed. CONCLUSION A MM meal consumed 4 h prior to 70 min of soccer competition does not increase gut symptoms and can be similarly ergogenic as a HCHO meal.
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Effects of antioxidant supplementation on oxidative stress balance in young footballers- a randomized double-blind trial.
Stankiewicz, B, Cieślicka, M, Kujawski, S, Piskorska, E, Kowalik, T, Korycka, J, Skarpańska-Stejnborn, A
Journal of the International Society of Sports Nutrition. 2021;(1):44
Abstract
BACKGROUND Intensive physical exercise that competitive sports athletes participate in can negatively affect their pro-oxidative-antioxidant balance. Compounds with high antioxidant potential, such as those present in chokeberry (Aronia melanocarpa), can prevent these adverse changes. We here investigated the effect of antioxidant supplementation on oxidative stress balance in young footballers. METHODS The study was designed as a double-blind randomized trial. Diet of a group of young football players (male; n = 20; mean age, 15.8 years-old) was supplemented with 200 ml of chokeberry juice per day, for 7 weeks. The players were randomly assigned to the experimental (supplemented, FP-S; n = 12) and control (placebo, FB-C; n = 8) groups. Before and after the supplementation period, the participants performed a beep test. Venous blood was sampled for serum analysis before, immediately after, 3 h, and 24 h after the beep test. Serum levels of thiobarbituric acid reactive products, 8-hydroxy-2'-deoxyguanosine, total antioxidant capacity, iron, hepcidin, ferritin, myoglobin, and albumin, and morphological blood parameters (red blood cells, (RBC), haemoglobin (HGB), haematocrit (HCT) mean corpuscular volume (MCV) mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and lactic acid) were determined. RESULTS Chokeberry juice supplementation did not significantly affect the outcome of the beep test. The supplementation did not significantly affect any of the morphological, biochemical, or performance parameters analysed. CONCLUSIONS Chokeberry juice supplementation did not affect the measured parameters in the studied population, which may indicate insufficient antioxidant capacity of the juice.
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Effects of Caffeine Supplementation on Physical Performance of Soccer Players: Systematic Review and Meta-Analysis.
Ferreira, RES, Pacheco, RL, de Oliveira Cruz Latorraca, C, Riera, R, Eid, RG, Martimbianco, ALC
Sports health. 2021;(4):347-358
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Abstract
CONTEXT Caffeine is 1 of the most popular supplements consumed by athletes, and the evidence for improving soccer performance remains limited. OBJECTIVE To investigate and update the effects (benefits and harms) of caffeine to improve performance on soccer players. DATA SOURCES Electronic search in Medline (via PubMed), CENTRAL, Embase, SPORTDiscus, and LILACS, from inception to March 28, 2020. STUDY SELECTION Randomized clinical trials (RCTs) assessing the effects of caffeine on the performance of soccer players. STUDY DESIGN Systematic review with meta-analysis. LEVEL OF EVIDENCE Level 1. DATA EXTRACTION Data extraction was conducted independently by 2 authors using a piloted form. We assessed methodological quality (Cochrane risk-of-bias [RoB] table) and the certainty of the evidence (GRADE [Grading of Recommendations Assessment, Development and Evaluation] approach). RESULTS Sixteen RCTs were included. Overall methodological quality was classified as unclear to low risk of bias. When assessing aerobic endurance, meta-analyses did not demonstrate the differences between caffeine and placebo (mean difference [MD], 44.9 m; 95% confidence interval [CI], -77.7 to 167.6). Similarly, no difference was observed during time to fatigue test (MD, 169.8 seconds; 95% CI, -71.8 to 411.6). Considering anaerobic power, meta-analyses also did not find differences for vertical jump (MD, 1.01 cm; 95% CI, -0.68 to 2.69) and repeated sprint tests (MD, -0.02 seconds; 95% CI, -0.09 to 0.04), as well as reaction time agility test (MD, 0.02 seconds; 95% CI, -0.01 to 0.04) and rating of perceived exertion (MD, 0.16 points; 95% CI, -0.55 to 0.87). Regarding safety, a few minor adverse events were reported. Based on the GRADE approach, the certainty of this evidence was classified as very low to low. CONCLUSION We found no significant improvement in soccer-related performance with caffeine compared with placebo or no intervention. However, caffeine appears to be safe.
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Effect of acute football activity and physical fitness on glycaemic and insulinaemic responses in adolescents.
Williams, RA, Cooper, S, Dring, KJ, Hatch, L, Morris, JG, Sunderland, C, Nevill, ME
Journal of sports sciences. 2021;(10):1127-1135
Abstract
The present study examined the metabolic responses to an acute bout of football and the overall and moderating role of physical fitness on these responses, in adolescents. Thirty-six adolescents (16 girls, 20 boys; 12.6±0.5 y) completed two trials (60-min football and 60-min seated rest) separated by 7-d. Capillary blood samples were taken at baseline (60-min prior to exercise/rest), immediately, 30- and 60-min post-exercise and 30-, 60- and 120-min following a standardised lunch (1.5-, 2- and 3-h post-exercise), for the determination of blood glucose and plasma insulin concentrations. The median split of distance covered on the multi-stage fitness test was used to define high- and low-fit groups. Overall plasma insulin tAUC following lunch was lower in high-fit participants compared to low-fit (high-fit: 3784.2±1653.1 pmol·L-1x120min, low-fit: 6457.3±3290.7 pmol·L-1x120min; p<0.001), although there was no acute effect of the football session (p>0.05). Football reduced blood glucose concentration 1-h post-exercise compared to control (exercise: 3.8±0.6 mmol·L-1, rest: 4.6±0.8 mmol·L-1; p<0.001), but this was similar for the high- and low-fit participants (p>0.05). Blood glucose tAUC was not affected by exercise or physical fitness (p>0.05). These data emphasise the importance of physical fitness for metabolic health in adolescents, as well as the utility of football as a popular form of games-based activity for improving glucose regulation.
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Effect of whey vs. soy protein supplementation on recovery kinetics following speed endurance training in competitive male soccer players: a randomized controlled trial.
Kritikos, S, Papanikolaou, K, Draganidis, D, Poulios, A, Georgakouli, K, Tsimeas, P, Tzatzakis, T, Batsilas, D, Batrakoulis, A, Deli, CK, et al
Journal of the International Society of Sports Nutrition. 2021;(1):23
Abstract
BACKGROUND Soccer-specific speed-endurance training induces short-term neuromuscular fatigue and performance deterioration over a 72-h recovery period, associated with elevated markers of exercise-induced muscle damage. We compared the effects of whey vs. soy protein supplementation on field activity, performance, muscle damage and redox responses following speed-endurance training in soccer players. METHODS Ten well-trained, male soccer players completed three speed-endurance training trials, receiving whey protein (WP), soy protein (SP) or an isoenergetic placebo (PL; maltodextrin) according to a randomized, double-blind, crossover, repeated-measures design. A pre-loading period was applied in each trial during which protein supplementation was individually adjusted to reach a total protein intake of 1.5 g/kg/day, whereas in PL protein intake was adjusted at 0.8-1 g/kg/day. Following pre-loading, two speed-endurance training sessions (1 and 2) were performed 1 day apart, over a 3-day experimental period. During each session, field activity and heart rate were continuously monitored using global positioning system and heart rate monitors, respectively. Performance (isokinetic strength of knee extensors and flexors, maximal voluntary isometric contraction, speed, repeated sprint ability, countermovement jump), muscle damage (delayed-onset of muscle soreness, creatine kinase activity) and redox status (glutathione, total antioxidant capacity, protein carbonyls) were evaluated at baseline (pre), following pre-loading (post-load), and during recovery from speed-endurance training. RESULTS High-intensity and high-speed running decreased (P ≤ 0.05) during speed-endurance training in all trials, but WP and SP mitigated this response. Isokinetic strength, maximal voluntary isometric contraction, 30-m speed, repeated sprint ability and countermovement jump performance were similarly deteriorated during recovery following speed-endurance training in all trials (P ≤ 0.05). 10 m speed was impaired at 24 h only in PL. Delayed-onset of muscle soreness, creatine kinase, total antioxidant capacity and protein carbonyls increased and glutathione decreased equally among trials following speed-endurance training (P ≤ 0.05), with SP inducing a faster recovery of protein carbonyls only at 48 h (P ≤ 0.05) compared to WP and PL. CONCLUSIONS In conclusion, increasing daily protein intake to 1.5 g/kg through ingestion of either whey or soy protein supplements mitigates field performance deterioration during successive speed-endurance training sessions without affecting exercise-induced muscle damage and redox status markers. TRIAL REGISTRATION Name of the registry: clinicaltrials.gov. TRIAL REGISTRATION NCT03753321 . Date of registration: 12/10/2018.
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Does Recreational Soccer Change Metabolic Syndrome Status in Obese Adolescents? A Pilot Study.
Vasconcellos, F, Cunha, FA, Gonet, DT, Farinatti, PTV
Research quarterly for exercise and sport. 2021;(1):91-99
Abstract
Purpose: To evaluate whether a soccer program (RSP) might lower risk factors related to metabolic syndrome (MetS) in obese adolescents. Methods: A 12-week randomized controlled trial [RSP: n = 6 (2 girls), age = 13.9 ± 1.6 yr, body mass index = 30.5 ± 2.1 kg/m2; Control: n = 7 (2 girls); age = 14.7 ± 2.3 yr, body mass index: 30.8 ± 3.1 kg/m2] was conducted. Participants underwent anthropometric, body fractioning, blood pressure, lipid profile, and glucose tolerance assessments at baseline and post-intervention. MetS status was determined based on waist circumference and at least two additional criteria: high blood pressure, hypertriglyceridemia, dyslipidemia, and hyperglycemia. RSP included eutrophic and overweight adolescents and consisted of small-sided games (85 ± 4% maximal heart rate) performed three times/week. Results: High-density lipoprotein increased [(HDL) ∆15.5 ± 5.2 mg·dL-1; p = .01] and triglycerides lowered [(TG) ∆-34.7 ± 7.1 mg·dL-1; p = .02] after RSP intervention. Between-group differences were also detected for changes in HDL (∆13.0 ± 6.1 mg·dL-1; p = .04) and TG (∆-47.1 ± 7.7 mg·dL-1; p = .05). The presence of MetS lowered in RSP (5 in 6 participants; p = .02), but not Control (1 in 7 participants; p = .32). Conclusion: A 12-week RSP was effective to reduce MetS risk factors and status in obese adolescents.
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Importance of anthropometric features to predict physical performance in elite youth soccer: a machine learning approach.
Bongiovanni, T, Trecroci, A, Cavaggioni, L, Rossi, A, Perri, E, Pasta, G, Iaia, FM, Alberti, G
Research in sports medicine (Print). 2021;(3):213-224
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The present study aimed to determine the contribution of soccer players' anthropometric features to predict their physical performance. Sixteen players, from a professional youth soccer academy, were recruited. Several anthropometric features such as corrected arm muscle area (AMAcorr), arm muscle circumference (AMC) and right and left suprapatellar girths (RSPG and LSPG) were employed in this study. Players' physical performance was assessed by the change of direction (COD), sprint (10-m and 20-m), and vertical jump (CMJ) tests, and Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IRT1). Using an extra tree regression (ETR) model, the anthropometric features permitted to accurately predict 10-m sprint, 20-m sprint and Yo-Yo IRTL 1 performance (p < 0.05). ETR showed that upper-body features as AMAcorr, and AMC affected 10-m and 20-m sprint performances, while lower-body features as RSPG and LSPG influenced the Yo-Yo IRTL 1 (Overall Gini importance ≥ 0.22). The model predicting COD and CMJ presented a poor level of prediction, suggesting that other factors, rather than anthropometric features, may concur to predict their changes in performance. These findings demonstrated that the upper- and lower-body anthropometric features are strictly related to sprint and aerobic fitness performance in elite youth soccer.
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Effects of 14-weeks betaine supplementation on pro-inflammatory cytokines and hematology status in professional youth soccer players during a competition season: a double blind, randomized, placebo-controlled trial.
Nobari, H, Cholewa, JM, Pérez-Gómez, J, Castillo-Rodríguez, A
Journal of the International Society of Sports Nutrition. 2021;(1):42
Abstract
OBJECTIVE Systemic elevations in pro-inflammatory cytokines are a marker of non-functional over reaching, and betaine has been shown to reduce the secretion of pro-inflammatory cytokines in vitro. The aim of this study was to investigate the effects of betaine supplementation on tumor necrosis factor alpha (TNF-α), interleukins-1 beta (IL-1β), - 6 (IL-6) and the complete blood cell (CBC) count in professional youth soccer players during a competitive season. METHODS Twenty-nine soccer players (age, 15.5 ± 0.3 years) were randomly divided into two groups based on playing position: betaine group (BG, n = 14, 2 g/day) or placebo group (PG, n = 15). During the 14-week period, training load was matched and well-being indicators were monitored daily. The aforementioned cytokines and CBC were assessed at pre- (P1), mid- (P2), and post- (P3) season. RESULTS Significant (p < 0.05) group x time interactions were found for TNF-α, IL-1β, and IL-6. These variables were lower in the BG at P2 and P3 compared to P1, while IL-1β was greater in the PG at P3 compared to P1 (p = 0.033). The CBC count analysis showed there was significant group by time interactions for white blood cells (WBC), red blood cells (RBC), hemoglobin (Hb), and mean corpuscular hemoglobin concentration (MCHC). WBC demonstrated increases at P3 compared to P2 in PG (p = 0.034); RBC was less at P3 compared to P1 in BG (p = 0.020); Hb was greater at P2 compared to P1, whilst it was less at P3 compared to P3 for both groups. MCHC was greater at P3 and P2 compared to P1 in BG, whereas MCHC was significantly lower at P3 compared to P2 in the PG (p = 0.003). CONCLUSION The results confirmed that 14 weeks of betaine supplementation prevented an increase in pro-inflammatory cytokines and WBC counts. It seems that betaine supplementation may be a useful nutritional strategy to regulate the immune response during a fatiguing soccer season.