Association of trunk and lower limb factors with shoulder complaints and sport performance in overhead athletes: A systematic review including GRADE recommendations and meta-analysis.

OBJECTIVE: To identify the association of trunk and lower limb factors with shoulder complaints and sport performance in overhead athletes. METHODS: Search performed at PubMed/Medline, Embase, CINAHL, LILACS, Cochrane, Web of Science and SPORTDiscus for observational studies. Methodological quality and strength of the evidence was assessed with the Newcastle-Ottawa Scale and GRADE. Meta-analysis and effects sizes analysis were calculated when possible. RESULTS: Sixty-five studies were included. Low to very-low evidence suggests no association of trunk/lower limb strength, endurance, power, jump or balance with shoulder complaints and/or throwing performance. Athletes with shoulder complaints performed worse in trunk stability and endurance tests (mean difference: -6.83 (95%CI: -8.78, -4.88)). Athletes with high throwing performance presented better results in CMJ, horizontal jump, power measures and knee extension strength. For swimmers, there was no association of trunk/lower limb endurance with shoulder complaints (moderate evidence) and no association of balance and swimming performance (low evidence). Better trunk/lower limb strength, power and vertical jumps measures were associated with better swimming performance. CONCLUSIONS: In methodologically similar studies, some trunk/lower limb outcomes are associated with shoulder complaint or sport/swimming performance. Results should be considered with caution and future studies should use better methodologies.

Sodium bicarbonate ingestion increases glycolytic contribution and improves performance during simulated taekwondo combat.

PURPOSE: To investigate the effect of sodium bicarbonate (NaHCO3) on performance and estimated energy system contribution during simulated taekwondo combat. METHODS: Nine taekwondo athletes completed two experimental sessions separated by at least 48 h. Athletes consumed 300 mg/kg body mass of NaHCO3 or placebo (CaCO3) 90 min before the combat simulation (three rounds of 2 min separated by 1 min passive recovery), in a double-blind, randomized, repeated-measures crossover design. All simulated combat was filmed to quantify the time spent fighting in each round. Lactate concentration [La-] and rating of perceived exertion (RPE) were measured before and after each round, whereas heart rate (HR) and the estimated contribution of the oxidative (WOXI), ATP (adenosine triphosphate)-phosphocreatine (PCr) (WPCR), and glycolytic (W[La-]) systems were calculated during the combat simulation. RESULTS: [La-] increased significantly after NaHCO3 ingestion, when compared with the placebo condition (+14%, P = 0.04, d = 3.70). NaHCO3 ingestion resulted in greater estimated glycolytic energy contribution in the first round when compared with the placebo condition (+31%, P = 0.01, d = 3.48). Total attack time was significantly greater after NaHCO3 when compared with placebo (+13%, P = 0.05, d = 1.15). WOXI, WPCR, VO2, HR and RPE were not different between conditions (P > 0.05). CONCLUSION: NaHCO3 ingestion was able to increase the contribution of glycolytic metabolism and, therefore, improve performance during simulated taekwondo combat.

Weight loss practices in Taekwondo athletes of different competitive levels.

This study investigated the prevalence, magnitude, and methods of rap-id weight loss among male and female Taekwondo athletes from all competitive levels. A questionnaire was administered to 72 men (regional/state level, n=31; national/international level, n=41) and 44 women (regional/state level, n=9; national/international, n=35). Among the male athletes, 77.4% of the regional/state level and 75.6% of the national/international athletes declared to have reduced weight to compete in lighter weight categories. Among women, 88.9% of regional/state level and 88.6% of national/international level reported the use of rapid weight loss strategies. Athletes reported to usually lose ~3% of their body weight, with some athletes reaching ~7% of their body weight. The methods used to achieve weight loss are potentially dangerous to health and no difference between sexes was found. Four methods were more frequently used by men athletes in higher competitive levels as compared to lower levels, as follows: skipping meals (Z=2.28, P=0.023, η(2)=0.21), fasting (Z=2.337, P=0.019, η(2)=0.22), restricting fluids (Z=2.633, P=0.009, η(2)=0.24) and spitting (Z=2.363, P=0.018, η(2)=0.22). Taekwondo athletes lost ~3% of their body mass, using methods potentially dangerous for their health. Although no difference was found between sexes, lower level athletes more frequently used methods such as skipping meals, fasting, restricting fluids and spitting. Considering that these health-threating methods are more commonly used by lower level athletes, specific education programs should be directed to them.