Effect of brain endurance training on maximal oxygen uptake, time-to-exhaustion, and inhibitory control in runners.

We aimed to analyze the effect of brain endurance training on maximum oxygen consumption (VO2máx ), time-to-exhaustion, and inhibitory control in amateur trained runners. We employed a mixed experimental design, with the group as the between-participant factor and time as the within-participant factor. 45 participants attended 36 training sessions over 12 weeks. The cognitive training group (CT) performed the Stroop word-color task [trials of each type (congruent, incongruent, and neutral) were randomly presented during each training session], the endurance training group (ET) participated in a running training program (intensity was 60%Δ of maximal aerobic velocity and performed on a motor-driven treadmill), and the brain endurance training group (BET) make cognitive and endurance training simultaneously over 12 weeks. The total time of each session (i.e., 20-40 min) was identical in the experimental groups. VO2máx , time-to-exhaustion, and inhibitory control tests were measured before (baseline) and after (post-experiment) the 12-week intervention. A significant effect of interaction (group × time) for VO2máx (p < 0.05) was found. A post-hoc test showed an increase in VO2máx from baseline to post-experiment only for ET (Δ% = 2.98) and BET (Δ% = 3.78) groups (p < 0.05). Also, the analyses showed a significant interaction (group × time) for time-to-exhaustion (p < 0.05), and a post-hoc test revealed an improvement in time-to-exhaustion for ET (Δ% = 8.81) and BET (Δ% = 11.01) (p < 0.05). No group × time interaction was found for accuracy and response time in the inhibitory control task (p > 0.05). The results conclude that BET was not superior to ET for improving VO2máx and time-to-exhaustion. Also, the findings conclude that BET improved inhibitory control similar to CT.

Head-to-head opponent mitigates mental fatigue effects during a 20-km time trial in well-trained cyclists.

We aimed to analyze the effect of a head-to-head virtual race on 20-km time trial performance in well-trained mentally fatigued cyclists. A total of 24 male professional cyclists participated in the present study, which was conducted in a within-factors design [four experimental conditions × four times (throughout 20-km time trial cycling)]. An avatar representing the participant on the racecourse was visible during the time trials. Then, a second virtual avatar representing the opponent was projected onto the screen in the mental fatigue head-to-head and control head-to-head experimental conditions. Measurements [rating of perceived exertion, heart rate, and eye-tracking measures (i.e., pupil diameter)] were performed every 5-km throughout the 20-km time trial. As a result, impaired total time, power output, and cadence throughout the 20-km cycling time trial were found for mental fatigue compared to mental fatigue head-to-head, control head-to-head, and control conditions (p < 0.05). Also, impaired 20-km time trial performance (total time, power output, and cadence) was found for mental fatigue head-to-head compared to control head-to-head (p < 0.05). Moreover, lower RPE was found for the control and control head-to-head conditions than mental fatigue head-to-head and mental fatigue experimental conditions (p < 0.05). Higher pupil diameter was also found for mental fatigue head-to-head, control head-to-head, and control than the mental fatigue experimental condition (p < 0.05). In summary, the overall performance throughout the 20-km cycling time trial was improved by the presence of a virtual opponent for the mentally fatigued cyclists.

The effect of tyrosine supplementation on whole-body endurance performance in physically active population: A systematic review and meta-analysis including GRADE qualification.

Although tyrosine supplementation is well recognized to improve cognitive function, its impact on endurance performance is debatable and needs to be clarified further. The purpose of this systematic review and meta-analysis was to evaluate the effects of tyrosine supplementation on whole-body endurance performance in physically active population. The search strategy follow the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), using four databases (Cochrane Library, Web of Science, Scopus, PsycINFO, and PubMed) until 3 August 2023. The effect of tyrosine (experimental condition) was compared against placebo (control condition). The methodological quality of the included studies was evaluated using the Physiotherapy Evidence Database (PEDro) scale. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE Pro software) System was also used to assess the quality of evidence. A total of 10 interventions from 8 studies were included. The sub-group analysis revealed no significant differences between tyrosine and placebo conditions for time to exhaustion (SMD = 0.02; p = 0.94) and time trial performance (SMD = -0.04; p = 0.85). The level of evidence as qualified with GRADE was moderate. In conclusion, moderate-quality evidence suggests that tyrosine supplementation is ineffective on endurance performance in the physically active population, independently of the endurance task (TTE or ETT).

Analysis of stress tolerance, competitive-anxiety, heart rate variability and salivary cortisol during successive matches in male futsal players.

BACKGROUND: This study aimed to compare the stress tolerance, competitive anxiety, heart rate variability and salivary cortisol before and during successive futsal competitive matches (3 matches in 4 days) in young male futsal players. METHODS: 10 young male futsal players (16.9 ± 0.7 age; 71.0 ± 5.1 kg; 174.9 ± 4.3 cm) were monitored during one training session and across a competitive period with 3 successive matches. External load was determined by the PlayerLoad method, while session rating of perceived exertion was used to calculate the internal training and competitive load. The stress tolerance was examined using Daily Analysis of Life Demand in Athletes questionnaire and the Competitive State Anxiety Inventory was used to analyze the competitive anxiety. The Time and frequency monitoring parameters were used to analyze the vagal cardiac autonomic marker. sC was analyzed using enzyme-linked immunosorbent assay. RESULTS: A generalized estimating equation showed a significant difference for PlayerLoad from M1 to TS, M2 and M3, from M2 to M3 (p < 0.05), and for session rating of perceived exertion from M1 to Ts and M3 (p < 0.05). A difference for sources [χ2 (3) = 1.481, p = 0.68] or symptoms [χ2 (3) = 3.893, p = 0.27] was not found. There was no significant difference in any of the competitive anxiety [cognitive anxiety (F (1.644; 14.799) = 4.6, p = 0.73, ŋ2 p = 0.28), somatic anxiety (F (2,09; 18,85) = 26.07 p = 0.057; ŋ2p = 0.27) or self-confidence (F(2.07; 18.85) = 15.875 p = 0.152; ŋ2p = 0.18)] domains. The HRV parameters (time domain and frequency) and Salivary Cortisol (sC) (χ2 (3) = 4.320 p = 0.229) did not significantly change during the successive matches. CONCLUSION: The competitive scenario in which the players were evaluated did not significantly modify the stress tolerance, or the athletes' state of anxiety, which in turn was not able to promote changes in the cardiac vagal modulation or in the sC levels before the matches.

Are COMT Val158Met (rs4680), DRD2 TaqIA (rs1800497), and BDNF Val66Met (rs6265) polymorphisms associated with executive functions performance at rest and during physical exercise?

Executive functions (EFs) encompass a wide array of cognitive processes, which appear to be influenced by genetic variants of the COMT, DRD2/ANKK1, and BDNF polymorphisms. The present study aimed to investigate whether COMT Val158Met (rs4680), DRD2/ANKK1 (rs1800497), and BDNF Val66Met (rs6265) polymorphisms were associated with EFs assessed at rest and during moderate acute physical exercise. Sixty physically active individuals underwent four laboratory visits. First, they filled out the pre-exercise survey, researchers collected their anthropometric data, and then performed a maximal cardiopulmonary exercise test. In the second and third sessions, participants performed EFs test in a randomized order: while the individual was seated on a cycle ergometer without pedaling (i.e., rest condition); and during physical exercise (pedaling for 30 minutes at moderate intensity before starting the EFs test during exercising). On the fourth day, blood samples were drawn. Our results showed that the response time of the COMT Val homozygotes group was significantly shorter than the COMT Met-carrier group [t(39.78) = 2.13, p = .039,d = 0.56] at rest condition. No significant association was found for the other analyses (DRD2/ANKK1 and BDNF). In conclusion, the present study suggests that COMT Val158Met (rs4680) polymorphisms may be associated with EFs at rest condition. However, further studies are needed to validate this association.

Short-Term Effects of Repeated-Sprint Training on Vertical Jump Ability and Aerobic Fitness in Collegiate Volleyball Players During Pre-Season.

The aim of this study was to assess the effect of repeated-sprint training (RST) on vertical jump ability and aerobic power in college volleyball players. Nineteen male volleyball players, aged between 18-24 years, were randomized into the RST group (RST; n = 10) and control group (CG; n = 9). The RST included 2-3 sets of 6×30m all-out sprints, twice per week, in addition to the regular training routine. The control group performed only the regular volleyball training sessions (i.e. mainly of technical-tactical drills). All players performed a maximal graded treadmill test, vertical countermovement jump (CMJ), and repeated-vertical jump ability (RVJA) test before and after 6-weeks of the training program. The following variables were determined from the RVJA: peak (RVJApeak), average (RVJAmean), and rate of decrement (RVJADec). A two-way ANOVA with repeated measures showed an interaction effect on CMJ (F (1,17) = 6.92; p = 0.018; η 2 = 0.289), RVJApeak (F (1,17) = 4.92; p = 0.040; η 2 = 0.225), maximal oxygen uptake (F (1,17) = 9.29; p = 0.007; η 2 = 0.353) and maximal speed attained in the treadmill test (F (1,17) = 8.66; p = 0.009; η 2 = 0.337), with significant improvements only on the RST group. In conclusion, RST, twice per week, improved RVJA and aerobic power in comparison to regular skill-based volleyball training.

Acute Effects of Parallel Back Squat Performed in Different Set Configurations on Neuromuscular Performance.

We compared the acute effects of parallel back squat performed from different resistance training configurations on neuromuscular performance. Twenty-eight young adults underwent 4 experimental conditions: inter-repetition rest, traditional, traditional to failure, and rest-pause in the parallel back squat in a randomized, counterbalanced, and cross-over design. The neuromuscular performance was assessed through peak torque of knee extensors and flexors at two angular velocities (90 and 120 º/s) in three moments (before, post, and post-30 min). The peak torque of the knee extensors and flexors at 90 and 120 º/s decreased immediately after training for traditional, traditional to failure, and rest-pause (-8.1% to -17.7%, P<0.001). A greater reduction in the extensor peak torque was found at 120 º/s (P<0.05) in the rest-pause (-17.7%) when compared to traditional (-10.8%). The peak torque returned to baseline values only at post-30 min for the traditional configuration for the knee flexion action at 120 º/s. The peak torque remained similar for the muscular actions and angular velocities for the inter-repetition rest (P>0.05). Our results suggest the inter-repetition rest configuration seems to be a more appropriate strategy for maintaining the lower limb neuromuscular performance after a resistance training session.

Frequência semanal de treino como um fator associado a dependência ao exercício em atletas recreacionais / La frecuencia de entrenamiento semanal como factor asociado a la dependencia del ejercicio en atletas recreativos / Weekly training frequency as a predictor of exercise dependence in recreational athletes

Este estudo transversal tevecomo objetivo investigar a associação da idade, frequência de treino e tempo de prática com o grau de dependência ao exercício (DE) de atletas recreacionais. Participaram 159 atletas recreacionais de corrida, musculação e crossfit, com média de idade de 31,59 ± 7,98 anos, do estado de Pernambuco. Os instrumentos utilizados foram um questionário sociodemográfico para caracterizar a amostra e a Exercise Dependence Scale-Revised para medir a DE. A análise dos dados foi conduzida por meio da Correlação de Spearman e a Regressão Múltipla (p < 0,05). Os resultados evidenciaram correlação significativa e positiva (p<0.05) da Frequência de treino com as dimensões de DE continuidade (r=0,16), redução de outras atividades (r=0,27), falta de controle (r=0,24), tempo (r=0,25) e escore geral de DE (r=0,25). A análise de regressão múltipla revelou que apenas a frequência de treino apresentou associação significativa e positiva com as dimensões de DE. Especificamente, a frequência semanal de treino explicou 1% da variânciada continuidade, 6% da redução de outras atividades, 5% da falta de controle, 5% do tempo e 7% do escore geral de DE. Concluiu-se que a frequência semanal de treino parece ser um fator interveniente no grau de DE em atletas recreacionais. (AU)

Este estudio transversal tuvo como objetivo investigar el papel predictivo de la edad, la frecuencia de entrenamiento y el tiempo de práctica en el grado dedependencia del ejercicio (DE) de los atletas recreativos. Participaron 159 atletas recreativos de atletismo, musculación y crossfit, con una edad media de 31.59 ± 7.98 años, del estado de Pernambuco. Los instrumentos utilizados fueron un cuestionario socio demográfico y la Exercise Dependence Scale-Revised. El análisis de los datos se realizó utilizando la correlación de Spearman y la Regresión Múltiple (p <0.05). Los resultados mostraron una correlación significativa y positiva (p <0.05) de la Frecuencia de entrenamiento con continuidad (r = 0.16), reducción en otras actividades (r = 0.27), falta de control (r = 0.24), tiempo (r = 0.25) y puntaje general de DE (r = 0.25). El análisis de regresión múltiple reveló que solo la frecuencia de entrenamiento tenía una predicción significativa y directa sobre las dimensiones de la DE. Específicamente, la frecuencia de entrenamiento semanal explica el 1% de la variación de continuidad, el 6% de la reducción en otras actividades, el 5% de la falta de control, el 5%del tiempo y el 57% de la puntuación general de DE. se concluye que la frecuencia semanal de entrenamiento parece ser un factor interviniente en el grado de DE en los atletas recreativos. (AU)

This cross-sectional study aimed to investigate the association of age, frequency of training and time of practice with the degree of dependence on exercise (DE) of recreational athletes. 159 recreational running, bodybuilding and crossfit athletes participated, with an average age of 31.59 ± 7.98 years, from the state of Pernambuco. The instruments used were a sociodemographic questionnaire to characterize the sample and the Exercise Dependence Scale-Revised to measure ED. Data analysis was conducted usingSpearman's Correlation and Multiple Regression (p <0.05). The results showed a significant and positive correlation (p <0.05) of the training frequency with the dimensions of DE continuity (r = 0.16), reduction in other activities (r = 0.27), lack of control (r = 0, 24), time (r = 0.25) and general DE score (r = 0.25). The multiple regression analysis revealed that only the training frequency had a significant and positive prediction on the dimensions of ED. Specifically, the weekly training frequency explains 1% of the continuity variance, 6% of the reduction in other activities, 5% of the lack of control, 5% of the time and 57% of the general ED score. It is concluded that the weekly frequency of training seems to be an intervening factor in the degree ofED in recreational athletes. (AU)

Parasympathetic Nervous Activity Responses to Different Resistance Training Systems.

The assessment of parasympathetic nervous activity and psychophysiological responses infers the stress imposed by different resistance training systems. Therefore, we compare the effects of different sets configurations, with similar volume (~60 repetitions), on heart rate variability indices and internal training load. Twenty-nine resistance-trained adults completed the following conditions: traditional without and with muscle failure, inter-repetition rest, and rest-pause in the parallel squat. The heart rate variability indices (time-domain) were measured before and 30 min after each condition. The internal training load was obtained through the session-rating of perceived exertion method. Except for inter-repetition rest, all conditions reduced the heart rate variability indices after the session (P<0.05), and the rest-pause triggered the higher reductions (≤-46.7%). The internal training load was higher in the rest-pause (≤68.9%). Our results suggest that rest-pause configuration leads to more considerable disruption of the parasympathetic nervous activity and higher internal training load in trained adults. In contrast, inter-repetition rest allows lower autonomic and psychophysiological stress.

Does rest interval between sets affect resistance training volume, density, and rating of perceived exertion when adopting the crescent pyramid system in young women?

BACKGROUND: The rest interval between sets can affect the responses to resistance training. Thus, the purpose of this study was to compare the effects of different rest intervals (RI) on volume, density, and rating of perceived exertion (RPE) when adopting a crescent pyramid (CP) system. METHODS: Twenty young women (21.1±2.6 years, 1.59±0.06 m, 58.5±9.3 kg) participated in this study. All participants performed three experimental sessions of the leg press exercise in 5 sets until voluntary muscular failure at 60%, 65%, 70%, 75%, and 80% of one-repetition maximum (1RM). A randomized and crossover design was used so that in each session one of three RI (RI-1 = 1 min, RI-2 = 2 min, and RI-3 = 3 min) was tested. RESULTS: The participants performed a significantly larger volume in the RI-3 (12820±3134 kg) when compared to RI-1 (10367±3053 kg) condition (P<0.05). The volume did not differ between RI-2 and RI-3 (P>0.05). The density was higher (P<0.05) in RI-1 (43.1±12.7 kg/s) when compared RI-2 (25.6±5.8 kg/s) and RI-3 (17.7±4.3 kg/s). The RI-2 presented higher density compared to RI-3 condition (P<0.05). The RPE was not different between the three conditions (P>0.05). CONCLUSIONS: The use of 2 minutes of rest between sets allowed the performance of a high volume-load and density of the session in young women. In addition, the three experimental sessions provided a high perception of effort.

Effect of 10% weight loss on simulated taekwondo match performance: a randomized trial.

The objective of the present study was to analyze the effect of 10% body mass reduction on simulated taekwondo match performance. Thirty-one male taekwondo athletes were randomly distributed in two groups: weight loss group (n= 15) - athletes in this group reduced 5% body mass per week during two successive weeks, totaling 10% body mass reduction; control group (n= 16) - athletes in this group kept their body mass constant during the 2-week period. Twenty-four hours before and after this period, athletes performed a simulated 3-round taekwondo match (6 min). Athletes wore body protectors to validate the scores during the match according to the official taekwondo rules. Match was filmed and actions were categorized using the Game Performance Assessment Instrument. There was a group and time interaction (P< 0.001) for body mass, with decrease only for the weight loss group (P= 0.001). A group and time interaction was also observed for the taekwondo match performance (P< 0.001), with performance increase being found only for the control group (P= 0.01). Thus, the 10% weight loss was not a good strategy to improve taekwondo skills' performance.