Standardized astragalus extract for attenuation of the immunosuppression induced by strenuous physical exercise: randomized controlled trial.

BACKGROUND: This paper aimed to verify how a supplementation of rower's diet with Astragalus Membranaceus Root (AMR) modulated their immune system response to maximal physical exertion. METHODS: The double-blind study included 18 members of the Polish Rowing Team assigned to the supplemented group (n = 10), and the placebo group (n = 8). The participants performed a 2000 m test on a rowing ergometer at the beginning and at the end of the six-week of intensive training camp during which the supplemented group received 500 mg of AMR. Blood samples were obtained prior to, 1 min after completing, and 24 h after the exertion test. The levels of interleukin 2 (IL2), interleukin 4 (IL4), interleukin 10 (IL10), interferon ɤ (IFN-É£), and lactic acid were determined. Subpopulations of T regulatory lymphocytes [CD4+/CD25+/CD127-] (Treg), cytotoxic lymphocytes [CD8+/TCRαß+] (CTL), natural killer cells [CD3-/CD16+/CD56+] (NK), and TCRδγ-positive cells (Tδγ) were determined with flow cytometry. RESULTS: After the camp, the initial NK and Treg levels sustained at the baseline, while Tδγ counts increased relative to the levels in the placebo group. In the supplemented subgroup, a decrease in IL2 level in reaction to maximal exertion clearly deepened while the change in IL-2/IL-10 level induced by the recovery after this exertion clearly increased, relative to the changes in the placebo group. CONCLUSIONS: AMR restored the immunological balance in strenuously trained athlets through a stabilization of NK and Treg cells with a positive trend in Tδγ towards Th1 response during restitution by cytokine IL2 modulation.

Nutritional Strategies to Optimize Performanceand Recovery in Rowing Athletes.

Rowing is a high-intensity sport requiring a high level of aerobic and anaerobic capacity. Although good nutrition is essential for successful performance in a rowing competition, its significance is not sufficiently established. This review aimed to provide nutritional strategies to optimize performance and recovery in rowing athletes based on a literature review. Following the guidelines given in the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA), we performed web searches using online databases (Pubmed, Web of Science, Wiley Online Library, ACS Publications, and SciFinder). Typically, a rowing competition involves a 6-8-min high-intensity exercise on a 2000-m course. The energy required for the exercise is supplied by muscle-stored glycogens, which are derived from carbohydrates. Therefore, rowing athletes can plan their carbohydrate consumption based on the intensity, duration, and type of training they undergo. For effective and safe performance enhancement, rowing athletes can take supplements such as ß-alanine, caffeine, ß-hydroxy-ß-methylbutyric acid (HMB), and beetroot juice (nitrate). An athlete may consume carbohydrate-rich foods or use a carbohydrate mouth rinse. Recovery nutrition is also very important to minimize the risk of injury or unexplained underperformance syndrome (UUPS) from overuse. It must take into account refueling (carbohydrate), rehydration (fluid), and repair (protein). As lightweight rowing athletes often attempt acute weight loss by limiting food and fluid intake to qualify for a competition, they require personalized nutritional strategies and plans based on factors such as their goals and environment. Training and competition performance can be maximized by including nutritional strategies in training plans.

Timing and Modulation of Activity in the Lower Limb Muscles During Indoor Rowing: What Are the Key Muscles to Target in FES-Rowing Protocols?

The transcutaneous stimulation of lower limb muscles during indoor rowing (FES Rowing) has led to a new sport and recreation and significantly increased health benefits in paraplegia. Stimulation is often delivered to quadriceps and hamstrings; this muscle selection seems based on intuition and not biomechanics and is likely suboptimal. Here, we sample surface EMGs from 20 elite rowers to assess which, when, and how muscles are activated during indoor rowing. From EMG amplitude we specifically quantified the onset of activation and silencing, the duration of activity and how similarly soleus, gastrocnemius medialis, tibialis anterior, rectus femoris, vastus lateralis and medialis, semitendinosus, and biceps femoris muscles were activated between limbs. Current results revealed that the eight muscles tested were recruited during rowing, at different instants and for different durations. Rectus and biceps femoris were respectively active for the longest and briefest periods. Tibialis anterior was the only muscle recruited within the recovery phase. No side differences in the timing of muscle activity were observed. Regression analysis further revealed similar, bilateral modulation of activity. The relevance of these results in determining which muscles to target during FES Rowing is discussed. Here, we suggest a new strategy based on the stimulation of vasti and soleus during drive and of tibialis anterior during recovery.

Athletes Play Through Pain-What Does That Mean for Rehabilitation Specialists?

CONTEXT: Pain in sport has been normalized to the point where athletes are expected to ignore pain and remain in the game despite the possible detrimental consequences associated with playing through pain. While rehabilitation specialists may not have an influence on an athlete's competitive nature or the culture of risk they operate in, understanding the consequences of those factors on an athlete's physical well-being is definitely in their area of responsibility. OBJECTIVE: To explore the factors associated with the experiences of subelite athletes who play through pain in gymnastics, rowing, and speed skating. DESIGN: The authors conducted semistructured interviews with subelite athletes, coaches, and rehabilitation specialists. They recruited coach participants through their provincial sport organization. Athletes of the recruited coaches who were recovering from a musculoskeletal injury and training for a major competition were then recruited. They also recruited rehabilitation specialists who were known to treat subelite athletes independently by e-mail. SETTING: An observation session was conducted at the athlete's training facility. Interviews were then conducted either in a room at the university or at a preferred sound-attenuated location suggested by the participant. PARTICIPANTS: The authors studied 5 coaches, 4 subelite athletes, and 3 rehabilitation specialists. INTERVENTIONS: The authors photographed athletes during a practice shortly before an important competition, and we interviewed all the participants after that competition. Our photographs were used during the interview to stimulate discussion. RESULTS: The participant interviews revealed 3 main themes related to playing through pain. They are: Listening to your body, Decision making, and Who decides. CONCLUSION: When subelite athletes, striving to be the best in their sport continue to train with the pain of an injury, performance is affected in the short-term and long-term consequences are also possible. Our study provides some insight into the contrasting forces that athletes balance as they decide to continue or to stop.

Inspiratory muscle training effects on oxygen saturation and performance in hypoxemic rowers: Effect of sex.

Exercise-induced arterial hypoxemia (EIAH) has been consistently reported in elite endurance athletes. This study examined the effects of an inspiratory muscle training protocol (IMT) on resting pulmonary function, end-exercise arterial oxygen saturation and performance in hypoxemic rowers. Twenty male and sixteen female well-trained hypoxemic rowers were divided into four groups: IMT-male, control-male, IMT-female and control-female. The IMT groups, additionally to the regular training, performed IMT (30 min/day, 5 times/week, 6 weeks). Before and after training, groups underwent an incremental rowing test, a 2000-m time trial and a 5-min "all-out" race. IMT increased respiratory strength in the IMT-male (135 ± 31 vs. 180 ± 22 cmH2O) and IMT-female (93 ± 19 vs. 142 ± 22 cmH2O) (P < 0.05). The IMT-female group exhibited lower EIAH and improved rowing performance in the 2000-m time trial (487 ± 32 vs. 461 ± 34 sec) and in the 5-min "all-out" test (1,285 ± 28 vs. 1,310 ± 36m) (P < 0.05). IMT protocol improved performance in IMT-male only in the 5-min test (1,651 ± 31 vs. 1,746 ± 37m) (P < 0.05). IMT may be a useful tool for increasing respiratory strength and enhancing performance in hypoxemic rowers, especially for women. Abbreviations: EIAH: Exercise-induced arterial hypoxemia; IMT: inspiratory muscle training protocol; PaO2: partial pressure of arterial oxygen; SaO2: arterial oxyhemoglobin saturation; VO2max: maximal oxygen consumption; [(A-a)DO2]: alveolar-to-arterial oxygen difference; VA/Q: ventilation-perfusion inequality/mismatching; PImax: maximal inspiratory pressure; BMI: body mass index; BSA: body surface area; FVC: vital capacity; FEV1: forced expiratory volume in 1 sec; VCin: vital capacity; MVV12: maximal voluntary ventilation in 12 sec.

The Impact of Preconditioning Strategies Designed to Improve 2000-m Rowing Ergometer Performance in Trained Rowers: A Systematic Review and Meta-Analysis.

PURPOSE: The 2000-m rowing-ergometer test is the most common measure of rowing performance. Because athletes use different intervention strategies for enhancing performance, investigating the effect of preconditioning strategies on the 2000-m test is of great relevance. This study evaluated the effects of different preconditioning strategies on 2000-m rowing-ergometer performance in trained rowers. METHODS: A search of electronic databases (PubMed, Google Scholar, and Web of Science) identified 27 effects of different preconditioning strategies from 17 studies. Outcomes were calculated as percentage differences between control and experimental interventions, and data were presented as mean ± 90% confidence interval. Performance data were converted to the same metrics, that is, mean power. Meta-regression analyses were conducted to assess whether performance level or caffeine dose could affect the percentage change. RESULTS: The overall beneficial effect on 2000-m mean power was 2.1% (90% confidence limit [CL] ±0.6%). Training status affected the percentage change with interventions, with a -1.1% (90% CL ±1.2%) possible small decrease for 1.0-W·kg-1 increment in performance baseline. Caffeine consumption most likely improves performance, with superior effect in higher doses (≥6 mg·kg-1). Sodium bicarbonate and beta-alanine consumption resulted in likely (2.6% [90% CL ±1.5%]) and very likely (1.4% [90% CL ±1.2%]) performance improvements, respectively. However, some preconditioning strategies such as heat acclimation, rehydration, and creatine resulted in small to moderate enhancements in 2000-m performance. CONCLUSIONS: Supplementation of caffeine and beta-alanine is a popular and effective strategy to improve 2000-m ergometer performance in trained rowers. Additional research is warranted to confirm the benefit of other strategies to 2000-m rowing-ergometer performance.

A walk on water: comparing the influence of Ai Chi and Tai Chi on fall risk and verbal working memory in ageing people with intellectual disabilities - a randomised controlled trial.

BACKGROUND: Aquatic motor intervention has been found to be effective in reducing falls and improving verbal working memory among the general population. However, effects among older adults with intellectual disabilities (ID) have never been explored. The aim of this study was to examine the effects of aquatic motor intervention on fall risk and verbal working memory among older adults with ID. METHODS: Forty-one older adults with mild to moderate ID (age: 50-66 years) were randomly assigned to 14 weeks of aquatic motor intervention (Ai Chi: N = 19) or identical on-land motor intervention (Tai Chi: N = 22). Fall risk, measured with the Tinetti balance assessment tool (TBAT), and verbal working memory, measured with the digit span forward test, were assessed pre-intervention, after 7 weeks of intervention and post-intervention. RESULTS: Study results indicate positive effects of both aquatic and on-land motor intervention on TBAT fall risk score, while the aquatic motor intervention group improved TBAT fall risk score quicker as compared with the on-land motor intervention group. Moreover, the lower the pre-intervention TBAT score was, the higher the improvement. In addition, study findings support the positive effects of aquatic motor intervention on verbal working memory ability as measured with the digit span forward test. CONCLUSIONS: Motor intervention, and particularly in an aquatic environment, can potentially reduce fall risk. Aquatic motor intervention may help to improve verbal working memory among older adults with ID.

The effect of two ß-alanine dosing strategies on 30-minute rowing performance: a randomized, controlled trial.

BACKGROUND: ß-alanine (ßA) supplementation has been shown to increase intramuscular carnosine content and subsequent high-intensity performance in events lasting < 4 minutes (min), which may be dependent on total, as opposed to daily, dose. The ergogenic effect of ßA has also been demonstrated for 2000-m rowing performance prompting interest in whether ßA may be beneficial for sustained aerobic exercise. This study therefore investigated the effect of two ßA dosing strategies on 30-min rowing and subsequent sprint performance. METHODS: Following University Ethics approval, twenty-seven healthy, male rowers (age: 24 ± 2 years; body-height: 1.81 ± 0.02 m; body-mass: 82.3 ± 2.5 kg; body-fat: 14.2 ± 1.0%) were randomised in a double-blind manner to 4 weeks of: i) ßA (2.4 g·d- 1, ßA1); ii) matched total ßA (4.8 g on alternate days, ßA2); or iii) cornflour placebo (2.4 g·d- 1, PL). Participants completed a laboratory 30-min rowing time-trial, followed by 3x30-seconds (s) maximal sprint efforts at days 0, 14 and 28 (T1-T3). Total distance (m), average power (W), relative average power (W·kg- 1), cardio-respiratory measures and perceived exertion were assessed for each 10-min split. Blood lactate ([La-]b mmol·L- 1) was monitored pre-post time-trial and following maximal sprint efforts. A 3-way repeated measures ANOVA was employed for main analyses, with Bonferonni post-hoc assessment (P ≤ 0.05). RESULTS: Total 30-min time-trial distance significantly increased from T1-T3 within ßA1 only (7397 ± 195 m to 7580 ± 171 m, P = 0.002, ƞp2 = 0.196), including absolute average power (194.8 ± 18.3 W to 204.2 ± 15.5 W, P = 0.04, ƞp2 = 0.115) and relative average power output (2.28 ± 0.15 W·kg- 1 to 2.41 ± 0.12 W·kg- 1, P = 0.031, ƞp2 = 0.122). These findings were potentially explained by within-group significance for the same variables for the first 10 min split (P ≤ 0.01), and for distance covered (P = 0.01) in the second 10-min split. However, no condition x time interactions were observed. No significant effects were found for sprint variables (P > 0.05) with comparable values at T3 for mean distance (ßA1: 163.9 ± 3.8 m; ßA2: 161.2 ± 3.5 m; PL: 162.7 ± 3.6 m), average power (ßA1: 352.7 ± 14.5 W; ßA2: 342.2 ± 13.5 W; PL: 348.2 ± 13.9 W) and lactate (ßA1: 10.0 ± 0.9 mmol·L- 1; ßA2: 9.2 ± 1.1 mmol·L- 1; PL: 8.7 ± 0.9 mmol·L- 1). CONCLUSIONS: Whilst daily ßA may confer individual benefits, these results demonstrate limited impact of ßA (irrespective of dosing strategy) on 30-min rowing or subsequent sprint performance. Further investigation of ßA dosage > 2.4 g·d- 1 and/or chronic intervention periods (> 4-8 weeks) may be warranted based on within-group observations.

Effects of Vitamin D Supplementation on Haematological Values and Muscle Recovery in Elite Male Traditional Rowers.

INTRODUCTION: Deficient levels of 25-hydroxyvitamin D (25(OH)D) (<30 ng/mL) may compromise health and athletic performance. Supplementation with oral vitamin D can favor the state of iron metabolism, and testosterone and cortisol as an indicator of muscle recovery of the athlete with a deficiency. The main aim of this study was to evaluate the influence of eight weeks of supplementation with 3000 IU/day of vitamin D on the hematological and iron metabolism profile, as well as on the analytical values of testosterone and cortisol on elite male traditional rowers. The secondary aim was to examine if serum 25(OH)D is a predictor of testosterone and cortisol levels. MATERIAL AND METHODS: Thirty-six elite male rowers (27 ± 6 years) were assigned to one of the two groups randomly: 1) Control group (CG, n = 18, height: 181.05 ± 3.39 cm and body mass: 77.02 ± 7.55 kg), 2) Group treated with 3,000 IU of vitamin D3/day (VD3G, s = 18, height: 179.70 ± 9.07 cm and body mass: 76.19 ± 10.07 kg). The rowers were subjected to blood tests at the beginning of the study (T1) and after eight weeks of treatment (T2), for the analysis of hematological and hormonal values. Repeated-measures ANOVA with group factor (GC and GVD3) were used to examine if the interaction of the different values was the same or different between the groups throughout the study (time × group) after vitamin D3 treatment. To analyze if 25(OH)D was a good predictor of testosterone, cortisol, and testosterone/cortisol ratio a stepwise regression model was performed. RESULTS: Statistically significant and different increases were observed in the group-by-time interaction of 25(OH)D in VD3G in respect to CG during the study (p < 0.001; VD3G (T1: 26.24 ± 8.18 ng/mL vs. T2: 48.12 ± 10.88 ng/mL) vs CG (T1: 30.76 ± 6.95 ng/mL vs. T2: 35.14 ± 7.96 ng/mL). Likewise, significant differences between groups were observed throughout the study in the group-by-time interaction and changes of hemoglobin (GC: -2.89 ± 2.29% vs. VD3G: 0.71 ± 1.91%; p = 0.009), hematocrit (CG: -1.57 ± 2.49% vs. VD3G: 1.16 ± 1.81%; p = 0.019) and transferrin (CG: 0.67 ± 4.88% vs. VD3G: 6.51 ± 4.36%; p = 0.007). However, no differences between groups were observed in the group-by-time interaction of the hormonal parameters (p > 0.05). Regression multivariate analysis showed that cortisol and testosterone levels were associated with 25(OH)D levels (p < 0.05). CONCLUSION: Oral supplementation with 3000 IU/day of vitamin D3 during eight weeks showed to be sufficient to prevent a decline in hematological levels of hemoglobin and hematocrit, and improve transferrin of 25(OH)D levels. However, although it was not sufficient to enhance muscle recovery observed by testosterone and cortisol responses, it was observed that serum 25(OH)D levels could be a predictor of anabolic and catabolic hormones.

Effects of 4 weeks of ß-alanine supplementation on aerobic fitness in water polo players.

The purpose of the present study was to investigate the ergogenic effects of 4 weeks of ß-alanine supplementation on peak oxygen uptake ([Formula: see text]) and force associated with [Formula: see text] ([Formula: see text]) during a tethered swimming graded exercise test, and a three-minute all-out effort (3minALL-OUT) in water polo players. Twenty-two male national competitive level water polo players were randomly assigned to receive either 4 weeks of ß-alanine (n = 11) or a placebo (n = 11) (i.e., 4.8 g·day-1 for 10 days, then6.4 g·day-1 for 18 days, resulting in 163.2 g over 28 days). The participants performed the TSGET and 3minALL-OUT before and after the supplementation period. There were no significant interaction effects between-groups for any variable, however, the magnitude-based inferences analyses showed a possibly beneficial effect (74%) of ß-alanine supplementation on [Formula: see text] compared to placebo treatment (Δ% [post-pre] for Placebo group = -5.2%; Δ% [post-pre] for ß-alanine group = +0.7%). Only the ß-alanine group presented a significant reduction in [Formula: see text] expressed in absolute values (PRE = 3.3±0.6L·min-1; POST = 3.0±0.4L·min-1; p = .021). Similarly, only the ß-alanine group presented a significant increase in critical force (PRE = 51.2±10.4N; POST = 56.5±13.1N; p = .044) and a reduction in the curvature constant parameter (W'; PRE = 2998.0±1103.7N·s; POST = 2224.6±1058.9N·s; p = .049). Thus, we can conclude that 4 weeks of ß-alanine supplementation presented mixed results in water polo players, indicating that this nutritional strategy may not be effective in improving parameters of the TSGET and 3minALL-OUT .

ß-Alanine Supplementation's Improvement of High-Intensity Game Activities in Water Polo.

OBJECTIVES: To investigate whether 4 wk of ß-alanine supplementation improves total distance covered, distance covered and time spent in different speed zones, and sprint numbers during a simulated water polo game. DESIGN: Double-blind, parallel, and placebo controlled. A total of 11 male water polo players participated in the study, divided randomly into 2 homogeneous groups (placebo and ß-alanine). METHODS: The participants performed a simulated water polo game before and after the supplementation period (4 wk). They received 4.8 g·d-1 of dextrose or ß-alanine on the first 10 d and 6.4 g·d-1 on the final 18 d. RESULTS: Only the ß-alanine group presented a significant improvement in total sprint numbers compared with the presupplementation moment (PRE = 7.8 [5.2] arbitrary units [a.u.]; POST = 20.2 [7.8] a.u.; P = .002). Furthermore, ß-alanine supplementation presented a likely beneficial effect in improving total distance covered (83%) and total time spent (81%) in speed zone 4 (ie, speed ≥ 1.8 m·s-1). There was no significant interaction effect (group × time) for any variable. CONCLUSIONS: Four weeks of ß-alanine supplementation slightly improved sprint numbers and had a likely beneficial effect on improving distance covered and time spent in speed zone 4 in a simulated water polo game.

An attempt to induce an immunomodulatory effect in rowers with spirulina extract.

BACKGROUND: The aim of this study was to analyze the response of selected components of the immune system in rowers to maximal physical exercise, and to verify if this response can be modulated by supplementation with spirulina (cyanobacterium Spirulina platensis). METHOD: The double-blind study included 19 members of the Polish Rowing Team. The subjects were randomly assigned to the supplemented group (n = 10), receiving 1500 mg of spirulina extract for 6 weeks, or to the placebo group (n = 9). The participants performed a 2000-m test on a rowing ergometer at the beginning (1st examination) and at the end of the supplementation period (2nd examination). Blood samples were obtained from the antecubital vein prior to each exercise test, 1 min after completing the test, and after a 24-h recovery period. Subpopulations of T regulatory lymphocytes (Tregs) [CD4+/CD25+/CD127-], cytotoxic lymphocytes (CTLs) [CD8+/TCRαß+], natural killer (NK) cells [CD3-/CD16+/CD56+] and TCRδγ-positive (Tδγ) cells were determined by means of flow cytometry. RESULTS: On the 2nd examination, athletes from the supplemented group showed neither a post-exercise increase in Treg count nor a post-recovery decrease in Tδγ cell count (both observed in the placebo group), and presented with significantly lower values of Treg/CTL prior to and after the exercise. During the same examination, rowers from the placebo group showed a significant post-recovery increase in Treg/(NK + Tδγ + CTL) ratio, which was absent in the supplemented group. CONCLUSION: The results of this study imply that supplementation with spirulina extract may protect athletes against a deficit in immune function (especially, anti-infectious function) associated with strenuous exercise, and may cause a beneficial shift in "overtraining threshold" preventing a radical deterioration of immunity.

No Effect of ß-alanine on Muscle Function and Kayak Performance.

PURPOSE: If ß-alanine supplementation counteracts muscular fatigue development or improves athletic performance was investigated. METHODS: Elite kayak rowers (10 men and 7 women) were supplemented with either 80 mg·kg body mass·d of ß-alanine or placebo for 8 wk. Muscular fatigue development was investigated by applying a 2-min elbow flexor maximal voluntary contraction (MVC). EMG was recorded continuously, and voluntary activation was determined 30, 60, 90, and 115 s into the 2-min MVC. In addition, performance was evaluated as 1000-m and 5 × 250-m kayak ergometer rowing. RESULTS: Force reduction during the 2-min MVC was similar before and after supplementation with ß-alanine (30.9% ± 10.3% vs 36.0% ± 14.1%) and placebo (35.5% ± 7.7% vs 35.1% ± 8.0%). No time effect was apparent in voluntary activation during the 2-min MVC. In addition, there was no detectable effect of ß-alanine supplementation on 1000-m kayak ergometer performance (ß-alanine: 0.26% ± 0.02% vs placebo: -0.18% ± 0.02%) or accumulated 5 × 250-m time (ß-alanine: -1.0% ± 0.3% vs placebo: -1.0% ± 0.2%). In 5 × 250 m, mean power output was reduced to a similar extent from first to fifth interval before and after supplementation with ß-alanine (23% ± 11% vs 22% ± 10%) and placebo (26% ± 13% vs 20% ± 5%). CONCLUSIONS: Two-minute MVC characteristics are unaffected by ß-alanine supplementation in elite kayakers, and likewise, both a 1000-m kayak ergometer time trial lasting 4-5 min and a 5 × 250-m repeated sprint ability were unaltered by supplementation.

Effects of Creatine Supplementation on Muscle Strength and Optimal Individual Post-Activation Potentiation Time of the Upper Body in Canoeists.

Creatine supplementation reduces the impact of muscle fatigue on post-activation potentiation (PAP) of the lower body, but its effects on the upper body remain unknown. This study examined the effects of creatine supplementation on muscle strength, explosive power, and optimal individual PAP time of the upper body during a set of complex training bouts in canoeists. Seventeen male high school canoeists performed a bench row for one repetition at maximum strength and conducted complex training bouts to determine the optimal individual timing of PAP and distance of overhead medicine ball throw before and after the supplementation. Subjects were assigned to a creatine or placebo group, and later consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After supplementation, the maximal strength in the creatine group significantly increased (p < 0.05). The optimal individual PAP time in the creatine group was significantly earlier than the pre-supplementation times (p < 0.05). There was no significant change in explosive power for either group. Our findings support the notion that creatine supplementation increases maximal strength and shortens the optimal individual PAP time of the upper body in high school athletes, but has no effect on explosive power. Moreover, it was found that the recovery time between a bench row and an overhead medicine ball throw in a complex training bout is an individual phenomenon.

Beta-Alanine Supplementation Improves Throwing Velocities in Repeated Sprint Ability and 200-m Swimming Performance in Young Water Polo Players.

The purpose of this study was to investigate the effects of beta-alanine supplementation on specific tests for water polo. Fifteen young water polo players (16 ± 2 years) underwent a 200-m swimming performance, repeated-sprint ability test (RSA) with free throw (shooting), and 30-s maximal tethered eggbeater kicks. Participants were randomly allocated into two groups (placebo × beta-alanine) and supplemented with 6.4g∙day-1of beta-alanine or a placebo for six weeks. The mean and total RSA times, the magnitude based inference analysis showed a likely beneficial effect for beta-alanine supplementation (both). The ball velocity measured in the throwing performance after each sprint in the RSA presented a very like beneficial inference in the beta-alanine group for mean (96.4%) and percentage decrement of ball velocity (92.5%, likely beneficial). Furthermore, the percentage change for mean ball velocity was different between groups (beta-alanine=+2.5% and placebo=-3.5%; p = .034). In the 30-s maximal tethered eggbeater kicks the placebo group presented decreased peak force, mean force, and fatigue index, while the beta-alanine group maintained performance in mean force (44.1%, possibly beneficial), only presenting decreases in peak force. The 200-m swimming performance showed a possibly beneficial effect (68.7%). Six weeks of beta-alanine supplementation was effective for improving ball velocity shooting in the RSA, maintaining performance in the 30-s test, and providing possibly beneficial effects in the 200-m swimming performance.

Effects of 4 Weeks of ß-Alanine Supplementation on Swim-Performance Parameters in Water Polo Players.

In water polo, several high-intensity efforts are performed, leading to the fatigue process due to accumulation of hydrogen ions, and thus ß-alanine supplementation could be an efficient strategy to increase the intramuscular acid buffer. Purpose To investigate whether 4 wk of ß-alanine supplementation enhances parameters related to water polo performance. Methods Twenty-two highly trained male water polo players of national level were randomly assigned to receive 28 d of either ß-alanine or a placebo (4.8 g/d of the supplement in the first 10 d and 6.4 g/d in the final 18 d). The participants performed 30-s maximal tethered swimming (30TS), 200-m swimming (P200m), and 30-s crossbar jumps (30CJ) before and after the supplementation period. Results The ß-alanine group presented significant increases in 30TS for mean force (P = .04; Δ = 30.5% ± 40.4%) and integral of force (P = .05; Δ = 28.0% ± 38.0%), as well as P200m (P = .05; Δ = -2.2% ± 2.6%), while the placebo group did not significantly differ for mean force (P = .13; Δ = 24.1% ± 33.7%), integral of force (P = .12; Δ = 24.3% ± 35.1%), or P200m (P = .10; Δ = -1.6% ± 3.8%). However, there was no significant group effect for any variable, and the magnitude-based-inference analysis showed unclear outcomes between groups (Cohen d ± 95%CL mean force = 0.16 ± 0.83, integral of force = 0.12 ± 0.84, and P200m = 0.05 ± 0.30). For 30CJ the results were similar, with improvements in both groups (placebo, Δ = 14.9% ± 14.1%; ß-alanine, Δ = 16.9% ± 18.5%) but with no significant interaction effect between groups and an unclear effect (0.14 ± 0.75). Conclusion Four weeks of ß-alanine supplementation does not substantially improve performance of 30TS, P200m, or 30CJ in highly trained water polo athletes compared with a control group.