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.

Young Basketball Players' Multiple Object Tracking Skills Were Unaffected by Stroop-Induced Mental Fatigue.

We aimed to examine the acute effect of mental fatigue on young basketball players' three-dimensional multiple object tracking (3D-MOT) skills. Our participants were 12 adolescent basketball players (M age = 16.66, SD = 1.87 years; M years of practice = 2.66, SD = 1.07 years). In nine lab visits, we used visits 1 to 7 to familiarize participants with 3D-MOT, a subjective scale of mental fatigue, and a Stroop task involving mental set shifting. In the last two visits, participants performed in both experimental (EXP) and control (CON) conditions that were presented in randomized order. In the EXP condition, participants performed 3D-MOT pre- and post-60 minutes of induced mental fatigue; in the CON condition, they watched a documentary. After each condition, B participants performed the National Aeronautics and Space Administration Task Load Index (NASA-TLX). 3D-MOT performance measures were the "score" and "fastest trial score success." The response time on the Stroop tasks increased throughout the mental fatigue inducement in the experimental condition (p = .0037). The NASA-TLX responses were higher following the EXP condition than following the CON condition for mental demand, temporal demand, and performance (all ps < .05). Still, there were no significant EXP versus CON differences on the 3D-MOT performance indicators.

Rapid weight gain predicts fight success in mixed martial arts - evidence from 1,400 weigh-ins.

We aimed to analyze whether rapid weight gain (RWG) between the official weigh-in and the time of the fight was associated with fight success in MMA. A total of 700 professional MMA fights involving 1,400 weigh-ins from 21 MMA promotions regulated by the California State Athletic Commission were analyzed. Multilevel logistic regression accounting for individual (i.e. athlete) and cluster levels (i.e. fights) was used to analyze the association of all measures with a theoretical relationship with the dependent variable and without interdependency with one another (i.e. %RWG, sex, body mass division, competition level) with the fight outcome (i.e. win or loss). The odds ratios (OR) with 95% confidence intervals (95%CI) were calculated. The highest mean %RWG was found for the flyweight, bantamweight, featherweight, and lightweight divisions. The %RWG significantly predicted the fight outcome (ß = 0.044; OR = 1.045; 95%CI = 1.014-1.078; p = 0.005) so that for each 1% of additional RWG, the chance of winning increased by 4.5%. With the largest sample to date and in a "real-world" scenario, the present results suggest that the magnitude of RWG is linked to the chance of winning in MMA combats. It is suggested that regulatory commissions, confederations, and event organisers should consider regulating RWG, considering that, despite its detrimental impact on the athletes' health and performance, the potential advantage might stimulate athletes to invest in rapid weight loss, followed by gain after the official weigh-in to increase their chance of winning.

Playing videogames or using social media applications on smartphones causes mental fatigue and impairs decision-making performance in amateur boxers.

This study aimed to analyze the effect of playing videogames and using social media applications on smartphones on decision-making and countermovement jump (CMJ) performance in amateur boxers. Twenty one boxers were enrolled in the study and were randomly assigned to all three experimental conditions [smartphone (30SMA), videogame (30VID), and control (CON)]. CMJ was measured before and 30-min after each experimental condition. The athletes ran simulated combat recorded for decision-making analysis. The boxers watched coaching videos (CON), used social media applications on smartphones (30SMA), and played video games (30VID) for 30 min just before the combat simulation. Both attack and defense decision-making performance were worse in both 30SMA and 30VID conditions compared to the CON condition (p = 0.001). Regarding CMJ, despite no condition effect (p = 0.96) been obtained, a time effect (p = 0.001) was observed; So, it was found a decrease in CMJ performance after all experimental conditions (p = 0.001), with no difference between them. Using social media applications on smartphones and playing video game impairs decision-making performance in amateur boxers, with no harms for CMJ performance.

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).

Non-invasive brain stimulation over the orbital prefrontal cortex maintains endurance performance in mentally fatigued swimmers.

BACKGROUND: Using anodal transcranial direct current stimulation (a-tDCS) on frontal brain areas might be a promising strategy to mitigates mental fatigue and maintain endurance performance swimmers. OBJECTIVE: The objective was to analyze the effect of a-tDCS over the orbital prefrontal cortex (oPFC) on endurance performance of mentally fatigued female amateur swimmer. METHODS: Nineteen female amateur swimmers participated in this study. In two experimental visits, the swimmers completed the 3-min all-out tethered swimming after performing a 30-min Stroop test with a-tDCS or placebo (Sham) stimulation over the left-oPFC. The brain stimulation conditions (i.e., a-tDCS and Sham) were performed in a double-blinded and counterbalanced order. RESULTS: It was found lower critical force, mean force, force minimum, fatigue index, and aerobic impulse for Sham than a-tDCS (p < 0.05). There was no main effect of condition for peak force (p >  0.05). CONCLUSION: We concluded that a-tDCS applied over the left-oPFC in female amateur swimmers mentally fatigued maintained endurance performance. From a practical point of view, the use of a-tDCS should be considered to counteract harmful cognitive effects and maintain endurance performance during competitive race events.

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.

Effect of mental fatigue on mean propulsive velocity, countermovement jump, and 100-m and 200-m dash performance in male college sprinters.

The objective of this study was to analyze the effect of mental fatigue on mean propulsive velocity (MPV), countermovement jump (CMJ), 100, and 200-m dash performance in college sprinters. A total of 16 male athletes of sprint events (100 and 200-m dash) participated in this study. Each participant underwent two baseline visits and then running under the three experimental conditions. Assessments (MPV and CMJ) occurred both before and after either smartphone use (SMA) or Stroop task (ST), or watching a documentary TV show about the Olympic Games (CON). Then, the athletes ran the simulated race (i.e. the 100 and 200-m dash). There was no condition (p > 0.05) or time effect (p > 0.05) for MPV, CMJ, 100-m, or 200-m dash performance. In conclusion, the present study results revealed no mental fatigue effect induced by SMA or ST on neuromuscular, 100-m or 200-m dash performance in male college sprinters.

Effects of Mental Fatigue Induced by Social Media Use on Volleyball Decision-Making, Endurance, and Countermovement Jump Performance.

We studied the effects of repeated inducements of mental fatigue (MF) from using social media on smartphones immediately before training sessions by young male volleyball athletes, focusing specifically on their decision-making, endurance, and countermovement jump performance (CMJ). We pair-matched 24 participants according to their decision-making abilities and then, randomly assigned them to one of two 4-week block training groups: control (CON) and smartphone use (SMA). For a 30-minute period before each training session, the CON group watched TV and the SMA group used social media apps on smartphones. We found a significant group x time interaction effect for decision making (attack, p = 0.03; passing, p = 0.02) during training blocks. More specifically, only the CON group improved their decision making (attack, p = 0.03; passing, p = 0.02). Both groups significantly improved their CMJ performance (p = .01), with no significant group x time interaction effect for CMJ (p = 0.91). Neither group significantly improved their endurance (p = 0.56). We concluded that 30-minutes of repetitive social media app use on a smartphone immediately before 4-weeks of volleyball training sessions negatively affected decision-making in young male volleyball athletes.

Performing Repetitions to Failure in Lower-Limb Single-Joint Exercise Does Not Reduce Countermovement Jump Performance in Trained Male Adults.

Performing repetitions to failure (RF) is a strategy that might acutely reduce neuromuscular performance, as well as increase the rating of perceived exertion (RPE) and the internal training load (ITL) during and after a resistance training (RT) session. Thus, this study aimed to analyze the acute effects of RF or repetitions not to failure (RNF) on countermovement jump (CMJ) performance and the ITL in trained male adults. Eleven men performed two experimental protocols in randomized order (RF vs. RNF). Under the RF condition, participants performed three sets of the leg extension exercise using 100% of the 10RM load and rest intervals of 180-s between sets. Under the RNF condition, participants were submitted to six sets of five repetitions with the same intensity and an 80-s rest interval between sets in the same exercise. The CMJ test was analyzed before and following (15-s and 30-min, respectively) each experimental session. The ITL was evaluated by multiplying the RPE and the total session time, 30-min after the protocol. No main effect or interaction time vs. condition was found for CMJ performance (p > 0.05). In contrast, the ITL showed higher values under the RF condition (p = 0.003). Therefore, even though RF-induced a greater ITL, our results suggest that adopting this strategy in one single-joint exercise for the lower limbs does not seem sufficient to reduce CMJ height.

Acute Effect of Drop-Set, Traditional, and Pyramidal Systems in Resistance Training on Neuromuscular Performance in Trained Adults.

ABSTRACT: Costa, BDV, Ferreira, MEC, Gantois, P, Kassiano, W, Paes, ST, de Lima-Júnior, D, Cyrino, ES, and Fortes, LS. Acute effect of drop-set, traditional, and pyramidal systems in resistance training on neuromuscular performance in trained adults. J Strength Cond Res 35(4): 991-996, 2021-The aim of this study was to analyze the acute effects of resistance training (RT) systems on lower- and upper-limb performance in trained adults. Eighteen male young adults with experience in RT aged from 18 to 26 years underwent the 3 experimental conditions (drop-set [DS], decrescent pyramid [DP], and traditional [TR]). The subjects performed 2 exercises (bench press and leg press 45°). In the DS condition, they underwent 2 sets of 10 repetitions at 12RM, followed by 5 additional repetitions with an intensity of 15RM with 6-minute interval rest between sets. In the DP, it was performed 3 sets of 10 repetitions at 10RM, 12RM, and 15RM, respectively, and the rest interval was 3 minutes between sets. In the TR, the subjects performed 3 sets of 10 repetitions at 12RM with 3 minutes of rest between sets. Countermovement jump, peak power (Wpeak), and force (Fpeak) in the bench press were evaluated in the baseline, before, and 30 minutes after the experimental sessions. Countermovement jump performance decreased significantly only after the DS and DP conditions (-6.7 and -1.9%, respectively). The groups were significantly different in the post-intervention; the DS condition presented lower values when compared with the DP (p = 0.01) and TR (p = 0.001). According to Fpeak and Wpeak, only DS condition significantly decreased the performance (-3.8 and -4.1%, respectively). The results indicate the DS and DP conditions impair the neuromuscular performance of the lower limbs, whereas for upper limbs, only DS condition negatively affect upper-limb performance.

Acute effects of equated volume-load resistance training leading to muscular failure versus non-failure on neuromuscular performance.

BACKGROUND/OBJECTIVE: The aim of this study was to compare the acute effects of resistance training to failure (TF) and non-failure (TNF) with volume-load equalization on neuromuscular performance in recreationally resistance-trained adults. METHODS: Twenty-two trained men (age 21.4 ± 2.3 years) were included in a controlled, randomized, and design cross-over investigation with two experimental conditions and one-week of washout interval between them. The participants performed parallel back-squat adopting TF or TNF with volume, intensity, and rest between sets equalized. Countermovement jump (CMJ) height and peak power (PP) were used as mechanical indicators of neuromuscular performance. The mechanical variables were assessed in five moments (pre-experiment, post 15-s, 10-min, 20-min, and 30-min). RESULTS: When compared with the TNF condition, TF presented greater decrement on CMJ height (P < 0.001) and PP (P < 0.001) performance. The CMJ height and PP performance in parallel back-squat exercise following the TNF condition returned to the pre-experiment values 10-min after (P > 0.05). On the other hand, the TF condition promoted greater decrement in CMJ and PP performance compared with the pre-experiment and TNF protocol even 20-30 min later (P < 0.05). CONCLUSION: These findings suggest that TF promotes greater acute impairment on neuromuscular performance even when volume-load is equalized.

The effect of smartphones and playing video games on decision-making in soccer players: A crossover and randomised study.

The objective of this study was to analyse the effect of the use of social networks in smartphones or playing video games on the passing decision-making performance in professional soccer athletes. Participants were 25 male professional soccer athletes (mean ± SD: age 23.4 ± 2.8 years). The participants performed three randomised conditions divided into three groups: control (CON), smartphone (SMA), and video game (VID). Before and after each experimental condition, the Stroop Task assessed the level of induced mental fatigue. Then, the athletes performed a simulated soccer match. A CANON® camera recorded the matches for further analysis on passing decision-making performance. A group effect was identified (p < .01) with impairment on passing decision-making performance for the SMA (p = .01, ES = 0.5) and VID (p = .01, ES = 0.5) conditions. We concluded that the use of social networks on smartphones and/or playing video games right before official soccer matches might impair the passing decision-making performance in professional soccer athletes.

Relative Age Effect is Modulated by Playing Position but is Not Related to Competitive Success in Elite Under-19 Handball Athletes.

This study aimed to verify the occurrence of the relative age effect (RAE) in male elite young handball athletes according to the playing position and its association with team performance in a World Championship. Data from 383 handball athletes from 24 countries who participated in the 7th World Men's Championship in the under-19 category were analyzed. RAE was investigated from the birth trimester of the athletes, their playing position, and final ranking in the Championship. The results showed an overrepresentation of athletes born in the first two trimesters (Q1 and Q2) (χ2(3) = 32.97; p < 0.001, ω = 0.29). The analysis of the athlete's position showed that most wings (χ2(3) = 18.37; p < 0.001, ω = 0.32) and backs (χ2(3) = 12.51; p = 0.006, ω = 0.34) were born in the first trimesters (Q1 and Q2). The ranking in the Championship presented no significant association with the date of the birth (p > 0.05). The results showed the existence of the RAE in youth handball elite athletes, especially for the back and wing positions. However, the strategy of selecting is questionable once the presence of RAE was not associated with competitive success.

Effect of Volume in Resistance Training on Inhibitory Control in Young Adults: A Randomized and Crossover Investigation.

Purpose: The aim of the study is to compare the effect of resistance training volume on inhibitory control in young adults with previous experience in resistance training. Method: All the 27 participants underwent 40-week experiment, divided in three training phases of 8-week duration. A washout period of 8 weeks between each of the training phases was carried out. The participants performed 1, 3, or 5 sets of the same exercises with equalized intensity (loading zones) and rest. Inhibitory control was assessed by the Stroop Test. Results: Interaction effect was found for inhibitory control accuracy [F (5,22) = 56.88, p < 0.01] and mean response time [F (5,22) = 83.02, p < 0.01] for 3 sets (p = 0.01; ES = 0.6) and 5 sets (p = 0.01; ES = 0.8) when compared to 1 set. Conclusion: In conclusion, 1 set of resistance training may provide insufficient volume stimulus for positive adaptation in inhibitory control when compared to 3 or 5 sets.