The aim of this study was to investigate the effect of ingesting sodium bicarbonate (SB) and sodium citrate (SC) on 400 m high-intensity swimming performance and blood responses. Six nationally ranked male swimmers (20.7 ± 2.1 yrs; 184 ± 6 cm; 79.9 ± 3.9 kg; 10.6 ± 1% body fat) participated in a double blinded, placebo controlled crossover trial. Ninety minutes after consuming SB (0.3 g·kg-1), SC (0.3 g·kg-1) or a placebo (PL) participants completed a single 400-m freestyle maximal test on three consecutive days. The order of the supplementation was randomized. Capillary blood samples were collected on 4 occasions: at rest (baseline), 60 min post-ingestion, immediately post-trial and 15 min post-trial. Blood pH, HCO3- concentration and base excess (BE) were determined. Blood pH, HCO3-, BE were significantly elevated from before loading to the pre-test (60 min post-ingestion) (p < 0.05) after SB ingestion, but not after SC ingestion (p > 0.05). Performance times were improved by 0.6% (p > 0.05) after supplementation of SB over PL in 5 out of 6 participants (responders). In contrast, ingestion of SC decreased performance by 0.2% (p > 0.05). No side effects were observed in either trial. Delayed blood response was observed after SC ingestion compared to SB and this provided no or modest ergogenic effect, respectively, for single bout high-intensity swimming exercise. Monitoring the magnitude of the time-to-peak level rise in alkalosis may be recommended in order to individualize the loading time accordingly before commencement of exercise.

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The nutritional intake of elite open water swimmers during competition is not well established, and therefore this case study aims to provide new insights by describing the feeding strategies adopted by an elite female swimmer (28 yrs; height; 1.71 m; body mass: 60 kg; body fat: 16.0%) in the FINA open water Grand Prix 2014.Seven events of varying distances (15-88 km) and durations (3-12 hrs) were included. In all events, except one, feeds were provided from support boats. Swimmer and support staff were instructed to track in detail all foods and beverages consumed during the events. Nutritional information was gathered from the packaging and dietary supplements labels and analyzed by nutrition software. Mean carbohydrate (CHO) and protein intake reached 83 ± 5 g·h-1 and 12 ± 8 g·h-1, respectively. Fat intake was neglected (~1 g·h-1). Mean in-race energy intake reached 394 ± 26 kcal·h-1. Dietary supplements in the form of sport beverages and gels, containing multitransportable CHO, provided 40 ± 4 and 49 ± 6% of all CHO energy, respectively. Caffeine (3.6 ± 1.8 mg·kg-1 per event) and sodium (423 ± 16 mg·h-1) were additionally supplemented in all events. It was established that continuous intake of high doses of CHO and sodium and moderate dose of caffeine were an essential part of the feeding strategy for elite-level high intensity ultra-endurance open-water swimming races. A well scheduled and well-prepared nutrition strategy is believed to have ensured optimal individual performance during Grand Prix events.

Much research has been done in sports nutrition in recent years as the demand for performance-enhancing substances increases. Higher intake of nitrates from the diet can increase the bioavailability of nitric oxide (NO) via the nitrate–nitrite–NO pathway. Nevertheless, the increased availability of NO does not always lead to improved performance in some individuals. This review aims to evaluate the relationship between the athlete’s training status and the change in time trial performance after increased dietary nitrate intake. Articles indexed by Scopus and PubMed published from 2015 to 2019 were reviewed. Thirteen articles met the eligibility criteria: clinical trial studies on healthy participants with different training status (according to VO2max), conducting time trial tests after dietary nitrate supplementation. The PRISMA guidelines were followed to process the review. We found a statistically significant relationship between VO2max and ergogenicity in time trial performance using one-way ANOVA (p = 0.001) in less-trained athletes (VO2 < 55 mL/kg/min). A strong positive correlation was observed in experimental situations using a chronic supplementation protocol but not in acute protocol situations. In the context of our results and recent histological observations of muscle fibres, there might be a fibre-type specific role in nitric oxide production and, therefore, supplement of ergogenicity.

Limited practical recommendations related to wearing compression garments for athletes can be drawn from the literature at the present time. We aimed to identify the effects of compression garments on physiological and perceptual measures of performance and recovery after uphill running with different pressure and distributions of applied compression. In a random, double blinded study, 10 trained male runners undertook three 8 km treadmill runs at a 6% elevation rate, with the intensity of 75% VO2max while wearing low, medium grade compression garments and high reverse grade compression. In all the trials, compression garments were worn during 4 hours post run. Creatine kinase, measurements of muscle soreness, ankle strength of plantar/dorsal flexors and mean performance time were then measured. The best mean performance time was observed in the medium grade compression garments with the time difference being: medium grade compression garments vs. high reverse grade compression garments. A positive trend in increasing peak torque of plantar flexion (60º·s-1, 120º·s-1) was found in the medium grade compression garments: a difference between 24 and 48 hours post run. The highest pain tolerance shift in the gastrocnemius muscle was the medium grade compression garments, 24 hour post run, with the shift being +11.37% for the lateral head and 6.63% for the medial head. In conclusion, a beneficial trend in the promotion of running performance and decreasing muscle soreness within 24 hour post exercise was apparent in medium grade compression garments.

REGULI, Z.; BERNACIKOVÁ, M. & KUMSTÁT, M.Anthropometric characteristics and body composition in aikido practitioners. Int. J. Morphol., 34(2):417-423, 2016. SUMMARY:Although aikido is a non-competitive martial art, it is recognised by SportAccord as worldwide practiced combat sport. There is a lack of scientific research in aikido and the influence of aikido practice on the human body is not known. This is the first study that presents anthropometric characteristics and body composition data in aikido practitioners. 33 adult male aikido athletes (age 36.5±9.6 years, height 178±8 cm, weight 81.2±10.1 kg) were measured. All subjects were divided from beginner to intermediate and advanced group, and were recruited from the Czech Aikido Federation which is officially recognised by the centre of aikido in Japan. As main methods, bio impedance and skinfold measurements were realized. In aikido, body composition does not play an important role compared to other martial arts. Average values are similar to reference of non-athlete population (BMI 25.6±2.7 kg/m, BF 17.18±5.18 %, FFM 65.71±7.69 kg, BSA 1.98±0.15 m 2 ). Even though, aikido has positive effects on body composition, it does not have a high impact. Thus, aikido players should also gain benefits from other aspects of martial arts.

The aim of the study is to investigate the comparative effect of compression sleeves, rest and active recovery on performance and immediate recovery from high-intensity cycling performance (HICP). Eight recreationally trained male cyclists completed three trials, each separated by one week. Each trial consisted of two 10-min high intensity exercise task (30-20-10 s maximal HICP bouts with 3 min 1 W/kg recovery) separated by application one of the three 24-min recovery strategies (active -cycling 1W/kg, ACT; passive -supine position, PAS; passive -sitting with compression sleeves; PAS+CS). Applied recovery strategy effectiveness was assessed via changes in blood lactate clearance (LA), acid-base changes and performance parameters (fatigue index, FI; peak power, PP and relative peak power). Fatigue index was significantly improved by ACT for 30s and 20s HICP. There was a significant decrease in FI for PAS + CS (p = 0.041) and PAS (p = 0.026) showing a negative impact of PAS + CS and PAS for keeping PP during 10s task. The rate of decrease in plasma LA concentration over the 24-min recovery period was significantly higher in ACT (0.50 ± 0.1 mmol/min) compared to PAS and PAS+CS (0.31 ± 0.07 mmol/l, p = 0.001, 0.37 ± 0.09 mmol/min, p = 0.024, respectively). The passive recovery strategies decreased the ability of keeping repeated maximal intensity cycling performance in contrast to active recovery. The use of compression calf sleeves has no significant additional effect on plasma lactate clearance after high intensity anaerobic exercise above resting condition.

Purpose: Change of direction speed (CODS) and reactive agility (RAG) are important qual-ities in futsal, but studies rarely examined the predictors of these conditioning capacities in players of advanced level. This study aimed to evaluate predictive validity of certain an-thropometric and conditioning capacities in evaluation of futsal specific CODS and RAG in top-level players. Methods: The sample comprised 54 male players from Croatia and Bosnia and Herzegovina, members of teams competing at the highest national rank, including national champions for the 2017–2018 competitive season in both countries. The variables comprised set of pre-dictors (body mass, body height, triceps skinfold, reactive strength index [RSI], sprint 10 m [S10M], and broad jump [BJ]; and four criteria: futsal specific CODS and RAG, performed with and without dribbling (CODS_D, CODS_WD, RAG_D, RAG_WD). To identify the asso-ciation between variables Pearson’s correlation and multiple regressions were calculated. Results: Observed predictors explained statistically significant (p < 0.05) percentage of vari-ance for all four criteria (Rsq: 0.28, 0.30, 0.23 and 0.25, for CODS_WD, CODS_D, RAG_WD, RAG_D, respectively). Body mass was significant predictor for all criteria (Beta: 0.35–0.51), with poorer performances in heavier players. In both performances which involved dribbling, significant predictors was RSI (Beta: −0.27 and −0.31 for CODS_D and RAG_D, respective-ly), with superior performances in players with better RSI. The S10M and BJ were not identi-fied as being significantly correlated to studied RAG and CODS performances. Conclusion: Study confirmed specific influence of studied predictors of futsal specific CODS and RAG with consistent negative influence of body mass on studied performances. Almost certainly this can be explained by specifics of RAG and CODS execution. Specifically, tests are performed over relatively small distances, with several changes of direction, which clear-ly mimic the futsal specific performances. Although sprint performance is often observed as important determinant of CODS and RAG, herein we did not confirm its predictive validity in explanation of futsal specific CODS and RAG. Future studies should evaluate other poten-tially important predictors of these capacities in futsal.