Influence of photobiomodulation therapy on the physical performance of women during the follicular phase of the menstrual cycle: A double-blind Sham-controlled randomized clinical trial.

To evaluate the effects of photobiomodulation on the physical performance of healthy women, considering the menstrual cycle. 27 physically active healthy women (age 25.68 ± 3.99 years; mass 63.76 ± 12.77 kg; height 1.65 ± 0.59 cm) during the initial follicular phase (FF1 and FF2) of the menstrual cycle underwent performance evaluations, through a supramaximal test, subjective perception of exertion, blood lactate, and evaluations in the isokinetic dynamometer. Photobiomodulation (PBM) (200J) and Sham (0J) therapy were applied 10 min before the performance evaluations on the quadriceps femoris, hamstrings, and triceps surae muscles. A significance level of 5% was adopted and the effect size was calculated by Cohen's d. It was not possible to observe a significant difference (p > 0.05) in any of the performance variables evaluated in the comparison between groups, only small effects for total distance, final subjective perception of exertion, lactate peak and lactate delta in the PBM group. PBM did not improve muscle performance, resistance to fatigue, perceived exertion, and blood lactate concentrations during a predominantly anaerobic test in healthy women during the FF of the menstrual cycle.

Effects of moderate-intensity intermittent hypoxic training on health outcomes of patients recovered from COVID-19: the AEROBICOVID study protocol for a randomized controlled trial.

BACKGROUND: Recent studies point to a lower number and reduced severity of cases in higher altitude cities with decreased oxygen concentration. Specific literature has shown several benefits of physical training, so, in this sense, physical training with hypoxic stimulus appears as an alternative that supports the conventional treatments of the COVID-19 patient's recovery. Thus, this study's primary aim is to analyze the effects of moderate-intensity intermittent hypoxic training on health outcomes in COVID-19 recovered patients. METHODS: A clinical trial controlled double-blind study was designed. Participants (30-69 years old) will be recruited among those with moderate to severe COVID-19 symptoms, approximately 30 days after recovery. They will be included in groups according to the training (T) and recovery (R) association with hypoxia (H) or normoxia (N): (a) TH:RH, (b) TN:RH, (c) TN:RN, and last (d) the control group. The 8-week exercise bike intervention will be carried out with a gradual load increase according to the established periods, three times a week in sets of 5 min, 90 to 100% of the anaerobic threshold (AT), and a 2.5-min break. Blood will be collected for genotyping. First, after 4 weeks (partial), after 8 weeks, and later, 4 weeks after the end of the physical training intervention, participants will perform assessments. The primary outcome is the maximum oxygen consumption (VO2peak). The secondary outcomes include lung function, inflammatory mediators, hematological, autonomic parameters, AT, body composition analysis, quality of life, mental health, anthropometric measurements, and physical fitness. The statistical analysis will be executed using the linear regression model with mixed effects at a 5% significance level. DISCUSSION: This study is designed to provide evidence to support the clinical benefits of moderate-intensity intermittent hypoxic training as a part of the treatment of patients recovered from COVID-19. It may also provide evidence on the efficacy and safety of intermittent hypoxic training in different health conditions. Lastly, this study presents an innovative strategy enabling up to 16 participants in the same training session. TRIAL REGISTRATION: ClinicalTrials.gov RBR-5d7hkv. Registered after the start of inclusion on 3 November 2020 with the Brazilian Clinical Trials Registry.

Beta-alanine fails to improve on 5000 m running time despite increasing PAT1 expression in long-distance runners.

BACKGROUND: Beta-alanine has become a dietary supplement widely used by athletes due to its ergogenic effect. However, there is still no consensus on the performance benefit of beta-alanine on exercise lasting longer than ten minutes. The present study aimed to evaluate the effect of beta-alanine supplementation on running performance and the expression of TauT and PAT1. METHODS: This double-blind, randomized study enrolled 16 long-distance runners (37±8 years) who were randomly allocated to two groups: placebo (PLA) and beta-alanine (BA) (4.8 g/day 1) for four weeks. Maximal oxygen consumption, anthropometry, body composition, and food intake were determined. Before and after the intervention, the athletes undertook a 5000 m running time trial. Venous blood (TauT and PAT1 expressions) and ear lobe capillary blood (lactate) collected before and after exercise. Between tests, we monitored the training variables. RESULTS: The results were analyzed by t-tests and an ANOVA of repeated measures, with Sidak's post hoc (P<0.05). PLA exhibited lower body fat than BA (8.7±2.2 vs. 11.5±2.8%, P=0.04). After supplementation, there was an increase in PAT1 expression in BA when compared to PLA (1.17±0.47 vs. 0.77±0.18, P=0.04). No significant differences were shown for the 5000 m running time in PLA (PRE: 1128±72; POST: 1123±72s) and BA (PRE: 1107±95; POST: 1093±86s). CONCLUSIONS: Although beta-alanine supplementation increased PAT1 expression, there was no statistically significant improvement in 5000 m running performance. However, individual responses should be considered as the BA showed a higher delta than the PLA.

Beta alanine supplementation effects on metabolic contribution and swimming performance.

BACKGROUND: Investigations of ß-alanine supplementation shows effects on metabolic (aerobic and anaerobic) participation and performance on swimming by a possible blood acidosis buffering. Considering this background, the objective of the present study was to analyze the effects of ß-alanine supplementation on metabolic contribution and performance during 400-m swim. METHODS: Thirteen competitive swimmers underwent a 6-week, double-blind placebo-controlled study, ingesting 4.8 g.day- 1 of ß-alanine or placebo. Before and after the supplementation period, the total anaerobic contribution (TAn) and 30-s all-out tethered swimming effort (30TS) were assessed. Anaerobic alactic (AnAl) and lactic energy (AnLa) was assumed as the fast component of excess post-exercise oxygen consumption and net blood lactate accumulation during exercise (∆[La-]), respectively. Aerobic contribution (Aer) was determined by the difference between total energy demand and TAn. In addition to conventional statistical analysis (Repeated measures ANOVA; p > 0.05), a Bayesian repeated measures ANOVA was used to evidence the effect probability (BFincl). RESULTS: No differences and effects were found between groups, indicating no supplementation effects. Repeated measures ANOVA, with confirmation of effect, was indicate reduce in ∆Lactate (p: 0.001; BFincl: 25.02); absolute AnLa (p: 0.002; BFincl: 12.61), fatigue index (p > 0.001; BFincl: 63.25) and total anaerobic participation (p: 0.008; BFincl: 4.89). CONCLUSIONS: Thus, the results demonstrated that all changes presented were evidenced as a result of exposure to the training period and ß-alanine supplementation doesn't affect metabolic contribution and performance during 400-m freestyle.

Photobiomodulation by light emitting diode applied sequentially does not alter performance in cycling athletes.

Analyze the effects of sequential application of photobiomodulation therapy (PBMT) at different wavelengths on the performance of cycling athletes. Cyclists (48 male, mean age 33.77 years) underwent a performance evaluation through an incremental test, VO2max, blood lactate analysis, perception of effort, infrared thermography, and isokinetic evaluations. Photobiomodulation (180 J) with infrared (IR 940 ± 10 nm), red (RED 620 ± 10 nm), mixed Red, and IR (RED/IR 620 + 940 nm) or Sham (disabled device) intervention occurred on three consecutive days and was applied to the quadriceps femoris bilaterally. Reevaluations were performed 24 h after the last application, with 1 week of follow-up. A significance level of 5% was adopted, and the effect size (ES) was calculated by Cohen's d. Results: There were no significant differences in the analyzed variables under any experimental condition (p > 0.005), but a moderate effect size was observed for torque peak at 60°/s on left lower limb (LLL) (ES = 0.67), average power at 60°/s of the right lower limb (RLL) (0.73), and LLL (ES = 0.65) and a considerable effect size in torque peak at 60°/s of the RLL (ES = 0.98) in the IR/RED group compared with sham 24 h after the last application. Moreover, a large effect size was observed for total time to exhaustion (ES = 1.98) and for VO2max (ES = 6.96), and a moderate effect size was seen for anaerobic threshold (ES = 0.62) in the IR/RED group compared with sham. Photobiomodulation, when not associated with training, was not able to produce a cumulative effect on the performance of cycling athletes. However, the association of two wavelengths seems to be better for increased performance. ClinicalTrials.gov Identifier: NCT03225976.

Açai pulp supplementation as a nutritional strategy to prevent oxidative damage, improve oxidative status, and modulate blood lactate of male cyclists.

PURPOSE: Açai pulp is a source of phytochemicals and has been associated with antioxidant, anti-inflammatory, and antigenotoxic effects. This study aimed to assess the effects of açai pulp consumption on oxidative, inflammatory, and aerobic capacity markers of cyclist athletes. RESEARCH METHODS AND PROCEDURES: A crossover, randomized, placebo-controlled, single-blind study was developed with ten male cyclists (33.5 ± 4.7 years old, body mass index of 23.9 ± 1.38 kg/m2, and training load around 1875 ± 238 AU/week). The athletes consumed 400 g/day of pasteurized açai pulp (AP) or placebo (PL) for 15 days, with a 30-day wash-out period between trials. Lipid peroxidation, serum antioxidant capacity, DNA damage in peripheral blood (Comet assay), IL-6 and TNF-alpha, blood lactate concentration during effort, anaerobic threshold intensity (ATi), maximum workload reached (Wmax), rating of perceived exertion threshold (RPET), and heart rate threshold (HRT) were evaluated before and after each intervention. Data were analyzed using a linear regression model with mixed effects (p ≤ 0.05). RESULTS: Increased serum antioxidant capacity (p = 0.006) and decreased lipid peroxidation (p = 0.01) were observed in subjects after intervention with AP. Blood lactate levels during effort significantly decreased (by 29%, p = 0.025) and ATi increased (p = 0.006) after AP. No significant effect on DNA damage was attributed to AP consumption. CONCLUSION: We found notable effects of AP intervention on antioxidant status in athletes. Both the reduction in blood lactate concentration and increase in ATi during the effort suggest an overall improvement in the aerobic capacity of the cyclists, confirming that AP consumption may influence variables associated with performance in endurance athletes.

Taurine supplementation increases irisin levels after high intensity physical training in obese women.

BACKGROUND: Irisin is a myokine/adipokine that under stimulus of physical exercise is able to improve thermogenic capacity in adipose tissue. Likewise, taurine supplementation has demonstrated similar effects on energy metabolism. Therefore, we hypothesized that taurine supplementation combined with physical training may induce an increase in irisin concentrations, optimizing energy metabolism in obese individuals. OBJECTIVE: To evaluate if taurine supplementation associated with a high intensity physical training program increases irisin levels in obese women. METHODS: double-blind study with 22 obese women (BMI 32.4 ±â€¯2.0 kg/m2, 36.6 ±â€¯6.4 years and sedentary) who were randomly divided into two groups, control group (GC, n = 14), exercised and supplemented with placebo (3 g of starch), and taurine group (GTAU, n = 8), exercised and supplemented with taurine (3 g). The subjects performed high intensity physical training, Deep Water Running (DWR), for 8 weeks, 3 times/week, for 50 min per training session, at 70-85% maximum heart rate. Resting metabolic rate (RMR) was evaluated by indirect calorimetry, body composition by deuterium oxide, plasma taurine by HPLC, plasma irisin by Multiplex Kit, and food consumption by food records. The results were analyzed by an ANOVA two way repeated measures mixed model, with the Sidak post hoc (p < 0.05). RESULTS: No changes were observed in body composition. DWR increased RMR independent of supplementation (p < 0.001) and irisin levels (pg/mL) showed a significant difference only in the GTAU in 1 h after exercise (p < 0.001). CONCLUSION: DWR associated with taurine supplementation resulted in increased plasma irisin concentrations after physical training in obese adult women.

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 .

Effect of concurrent training and supplementation with ß-hydroxy- ß-methylbutyirate (hmb) on the prostate: alterations in the androgen receptor and inflammation / Efecto del entrenamiento concomitante y suplementación con ß-hidroxi-ß-metilbutirato (hmb) en la próstata: alteraciones en el receptor de andrógenos y la inflamación

SUMMARY: Supplementation is a strategy to potentiate physical training through hypertrophy of skeletal muscles, but other tissues such as the prostate may also be affected. Changes in prostate size and function are associated with the behavior of individuals, but evidence for an association with supplementation is scarce. Therefore, the aim of our study was to evaluate the effect of b-hydroxy bmethylbutyrate (HMB) supplementation and concurrent training on the prostate. Wistar rats were divided randomly into four groups with 10 animals each: control group (C), supplemented group (S), training group (T), and supplemented plus training group (TS). The supplemented groups (S and TS) received 76 mg·kg/day of HMB and the concurrent training groups (T and TS) performed exercise three times per week for eight weeks. HMB increased body composition, total weight of the prostate, and altered the histology of prostatic compartments. The lateral prostate of animals in the supplemented group had an increase in mast cells per mm2 (28.0 ± 3.9) compared to the control and exercise group (6.1 ± 3.0; 2.3 ± 0.9) There was also an increase in inflammation in the stroma and lumen of the prostate, and increased expression of androgen receptor (AR) in the supplemented and trained supplemented group (79.8 ± 2.1; 76.8 ± 11.4) in relation to the trained group (61.5 ± 7.0). We concluded that HMB alters hormone receptors that induce morphological changes and inflammation, and animals in the concurrent training group had normal inflammatory and hormonal profiles, and favorable prostatic histology.

RESUMEN: La suplementación con β-hidroxi β-metilbutirato (HMB) es una estrategia para potenciar el entrenamiento físico a través de la hipertrofia de los músculos esqueléticos, pero otros tejidos como la próstata también pueden verse afectados. Los cambios en el tamaño y la función de la próstata están asociados con el comportamiento de las personas, pero la evidencia de una asociación con la suplementación es escasa. Por lo tanto, el objetivo de nuestro estudio fue evaluar el efecto de la suplementación con β-hidroxi βmetilbutirato (HMB) y el entrenamiento concurrente en la próstata. Las ratas Wistar se dividieron aleatoriamente en cuatro grupos con 10 animales cada uno: grupo de control (C), grupo suplementado (S), grupo de entrenamiento (T) y grupo de entrenamiento suplementado (TS). Los grupos suplementados (S y TS) recibieron 76 mg•kg / día de HMB y los grupos de entrenamiento concurrentes (T y TS) realizaron ejercicio tres veces por semana durante ocho semanas. HMB aumentó la composición corporal, el peso total de la próstata y alteró la histología de los compartimentos prostáticos. La próstata lateral de los animales en el grupo suplementado tuvo un aumento en los mastocitos por mm2 (28,0 ± 3,9) en comparación con el grupo de control y ejercicio (6,1 ± 3,0; 2,3 ± 0,9) También hubo un aumento de la inflamación en el estroma y la luz de la próstata, y aumento de la expresión del receptor de andrógenos (AR) en el grupo suplementado y entrenado (79,8 ± 2,1; 76,8 ± 11,4) en relación con el grupo entrenado (61,5 ± 7,0). Concluimos que el HMB altera los receptores de hormonas que inducen cambios morfológicos e inflamación, y los animales en el grupo de entrenamiento concurrente tenían perfiles inflamatorios y hormonales normales y una histología prostática favorable.

Taurine supplementation can increase lipolysis and affect the contribution of energy systems during front crawl maximal effort.

Taurine can affect the energy system metabolism, specifically the lipid metabolism, since an increase in lipid oxidation may promote carbohydrate savings. We hypothesized that taurine supplementation associated with high-intensity exercise could increase levels of lipolysis, benefiting swimmer performance. Nine male competitive swimmers performed two 400-m front crawl maximal efforts with a 1-week washout, and the athletes received 6 g of taurine (TAU) or placebo (PLA) supplementation 120 min before performing the effort. Oxygen consumption and the contribution of the energy systems were analyzed post effort using a Quark CPET gas analyzer. Blood samples were collected before, and 5 min post the effort for taurine and glycerol analysis. Immediately before and 3, 5, and 7 min post the effort, blood samples from the earlobe were collected to determine lactate levels. An increase of 159% was observed in taurine plasma levels 120 min post ingestion. Glycerol levels were higher in both groups post effort; however, the TAU condition promoted an 8% higher increase than the PLA. No changes were observed in swimmer performance or lactate levels; however, the percentage change in lactate levels (∆[La-]) was different (TAU: 9.36 ± 2.78 mmol L-1; PLA: 11.52 ± 2.19 mmol L-1, p = 0.04). Acute taurine supplementation 120 min before performing a maximal effort did not improve swimmer performance; however, it increased glycerol plasma levels and reduced both the ∆[La-] and lactic anaerobic system contribution.

Effects of taurine on markers of muscle damage, inflammatory response and physical performance in triathletes.

BACKGROUND: The practice of prolonged exercise with high intensity, as seen in triathlon training, can cause physiological imbalances that might result in muscle fatigue, muscle damage and changes in systemic inflammatory response, thus reduce the athletes' physical performance, therefore, both adequate total caloric and macronutrient intake also the use of a specific ergogenic aid, as taurine supplementation would be an alternative to prevent inflammation and muscle damage. In order to verify the effects of 8 weeks of taurine and chocolate milk supplementation, markers of muscle damage, inflammation, and aerobic capacity were quantified in triathletes. METHODS: A double-blind, crossover, randomized study was conducted with 9 male long-distance triathletes, aged 25-35 years. Supplementation of 3 g of taurine (TAU) or placebo (PLA) associated with 400 mL low fat chocolate milk was performed during an 8-week period. In order to verify the effects of the supplementation protocol markers of muscle damage as lactate dehydrogenase (LDH) and creatine kinase (CK), and inflammatory markers tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were quantified, also triathletes' performance was evaluated by exhaust test on a treadmill. RESULTS: It was observed a significant increase in taurine and CK plasma levels after TAU supplementation (P=0.02 and P=0.01, respectively). However, LDH concentrations did not differ significantly after the supplementations performed, and there were no changes in physical performance parameters; anaerobic threshold, perceived exertion, heart rate, and the concentrations of IL-6 and TNF-α. CONCLUSIONS: Taurine supplementation did not provide benefits on performance and muscle damage in triathletes.

Effects of taurine supplementation in elite swimmers performance

AIM: Taurine is considered a semi-essential amino acid characterized by having various physiological functions in the body that modulate mechanisms of action involved in the muscle contraction process, increased energy expenditure, insulin signaling pathway, carbohydrate metabolism, and scavenging free radicals. These functions are crucial for aerobic exercise performance; thus, taurine supplementation may benefit athletes' performance. The objective of this study was to evaluate the effects of taurine supplementation on the resting energy expenditure and physical performance of swimming athletes. METHODS: In a double-blind study, 14 male swimmers were randomized into two groups: the taurine group (n = 7) and the placebo group (n = 7), which received 3 g per day of taurine or placebo in capsules during 8 weeks. Resting energy expenditure, plasma taurine, physical performance, anthropometry, dietary consumption were measured and an incremental test was performed to determine their maximal front crawl swimming performances before and after the 8-week period. RESULTS: The levels of serum taurine (p < 0.0001) and lactate (p = 0.0130) showed a significant increase in the taurine group; however, the other variables were not different. No changes were observed in the resting energy expenditure, mean speed performed, and the anaerobic threshold of the swimmers post-supplementation period. CONCLUSION: Supplementation of taurine increased plasma concentrations of this amino acid, but did not lead to significant changes in food intake, rest energy expenditure, and athletes' performance. However, the supplemented group presented a higher lactate production, suggesting a possible positive effect of taurine on the anaerobic lactic metabolism.(AU)

Taurine: A Potential Ergogenic Aid for Preventing Muscle Damage and Protein Catabolism and Decreasing Oxidative Stress Produced by Endurance Exercise.

The aim of this study was to evaluate the effects of taurine and chocolate milk supplementation on oxidative stress and protein metabolism markers, and aerobic parameters in triathletes. Methods: A double-blind, crossover study was conducted with 10 male triathletes, aged 30.9 ± 1.3 year, height 1.79 ± 0.01 m and body weight 77.45 ± 2.4 kg. Three grams of taurine and 400 ml of chocolate milk (TAUchoc), or a placebo (chocolate milk) (CHOC) was ingested post exercise for 8 weeks. Oxidative stress marker levels, and 24 h urinary nitrogen, creatinine, and urea excretion were measured before and after 8 weeks of training and supplementation with TAUchoc or CHOC. A maximal incremental running test on a treadmill was performed in order to evaluate aerobic parameters: Vmax, heart rate (HR) and rate of perceived exertion (RPE). Results: TAUchoc treatment during the 8 weeks resulted in increased taurine plasma levels (PRE 201.32 ± 29.03 µmol/L and POST 234.36 ± 35.51 µmol/L, p = 0.01), decreased malondialdehyde levels (19.4%, p = 0.03) and urinary nitrogen excretion (-33%, p = 0.03), and promoted positive nitrogen balance (p = 0.01). There were no changes in reduced glutathione (TAUchoc PRE 0.72 ± 0.08 mmol/L and POST 0.83 ± 0.08 mmol/L; CHOC PRE 0.69 ± 0.08 mmol/L and POST 0.81 ± 0.06 mmol/L), vitamin E plasma levels (TAUchoc PRE 33.99 ± 2.52 µmol/L and 35.95 ± 2.80 µmol/L and CHOC PRE 31.48 ± 2.12 µmol/L and POST 33.77 ± 3.64 µmol/L), or aerobic parameters, which were obtained in the last phase of the maximal incremental running test (Vmax TAUchoc PRE 13 ± 1.4 km/h and POST 13.22 ± 1.34 km/h; CHOC PRE 13.11 ± 2.34 km/h and POST 13.11 ± 2.72 km/h), the heart rate values were TAUchoc PRE 181.89 ± 24.18 bpm and POST 168.89 ± 46.56 bpm; CHOC PRE 181.56 ± 2.14 bpm and POST 179.78 ± 3.4 bpm, and the RPE were TAUchoc PRE 8.33 ± 2.4 AU and POST 9.1 ± 2.1 AU; CHOC PRE 8.11 ± 4.94 AU and POST 8.78 ± 2.78 AU). Conclusion: Taurine supplementation did not improve aerobic parameters, but was effective in increasing taurine plasma levels and decreasing oxidative stress markers, which suggests that taurine may prevent oxidative stress in triathletes.

Effects of HMB supplementation on body composition of rats / Efectos de la suplementación con HMB sobre la composición corporal en ratas

The aim was to investigate the effects of HMB supplementation on the physical performance and anthropometric parameters of Wistar rats that underwent eight weeks of concurrent training. We used 22 male Wistar rats of approximately 60 days of age, And were divided into four groups: control (C), supplemented control (SC), exercise (E) and supplemented exercise (SE). The training consisted of 30 minutes of swimming with an overload corresponding to 70 % of the anaerobic threshold, a one-minute interval, and four sets of ten jumps in water with a one minute interval between sets and a load of 50 % of body weight. After the tests, the tLIM and tTESTE were obtained and used to evaluate the performance of the animals, and anthropometric indices evaluated. The weight increases during the treatment in the SC animals was significantly higher than the animals in groups C and E. The absolute weight of the muscles, kidney and epididymal fat showed higher values for the SC and SE groups in relation to the others.

Se investigaron los efectos de la suplementación con HMB en el rendimiento físico y los parámetros antropométricos de ratas Wistar sometidas a ocho semanas de entrenamiento concurrente. La muestra consistió en 22 ratas Wistar machos, aproximadamente de 60 días de edad, los que fueron divididos en cuatro grupos: control (C), control suplementado (CS), ejercicio (E) y ejercicio suplementado (ES). El entrenamiento consistió en 30 minutos de natación correspondiente a 70 % de la sobrecarga del umbral anaeróbico, un intervalo de un minuto y cuatro series de diez saltos en el agua con intervalo de un minuto entre series y una carga del 50 % del peso del cuerpo. El tLIM y tTESTE se utilizaron para evaluar el rendimiento de los animales, y los índices antropométricos. El aumento de peso durante el tratamiento CS fue significativamente más alto que las de los grupos C y E. El peso absoluto de los músculos, los riñones y la grasa del epidídimo mostraron valores más altos en los grupos CS y ES en relación con los demás.

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.

Effects of Four Weeks of ß-Alanine Supplementation on Repeated Sprint Ability in Water Polo Players.

The purpose of this study was to investigate the effect of four weeks of ß-alanine supplementation on repeated sprint ability in water polo players. Twenty-two male water polo players participated in the study, divided randomly into two homogeneous groups (placebo and ß-alanine groups). The study design was double-blind, parallel and placebo controlled. Before and after the supplementation period (28 days), the athletes performed two specific repeated sprint ability tests interspaced by a 30-minute swimming test. Participants received 4.8g∙day-1 of the supplement (dextrose or ß-alanine) on the first 10 days and 6.4g∙day-1 on the final 18 days. There was no significant group-time interaction for any variable. The qualitative inference for substantial changes demonstrated a likely beneficial effect in the ß-alanine group (ß-alanine vs placebo) for mean time (6.6±0.4s vs 6.7±0.4s; 81% likely beneficial), worst time (6.9±0.5s vs 7.1±0.5s; 78% likely beneficial) and total time (39.3±2.5s vs 40.4±2.5s; 81% likely beneficial) in the first repeated sprint ability set and for worst time (7.2±0.6s vs 7.5±0.6s; 57% possible beneficial) in the second repeated sprint ability set. Further, was found substantial change for total time for both repeated sprint ability tests (80.8±5.7s vs 83.4±5.6s; 52% possible beneficial). To conclude, four weeks of ß-alanine supplementation had a likely beneficial effect in the first set of repeated sprint ability tests and a possible beneficial effect for worst time in the second set performed in a specific protocol in water polo players.