Carbohydrate mouth rinse improves performance of mentally fatigued cyclists despite null effects on psychological responses

Mental fatigue reduces exercise performance through an impaired psychological response such as increased perceived exertion. Carbohydrate (CHO) mouth rinses improve exercise performance and perceived exertion likely due to an improved activation in cerebral reward areas, then we investigated if the CHO mouth rinse-improved exercise performance in mentally fatigued individuals was associated with ameliorated reward-related psychological responses. We hypothesised that CHO mouth rinse would be beneficial for mentally fatigued cyclists mainly in high-metabolic disturbance intensities. After familiarization and baseline sessions, well trained cyclists (n = 20) performed a maximal incremental test (MIT) after mental fatigue induction. They completed the MIT either without mouth rinse (MF) or rinsing their mouth with CHO (MF+CHO) or placebo (FM+PLA) solutions at every 25 % of the MIT. Psychological responses such as ratings of perceived exertion (RPE), affective valence, emotional arousal, and motivation were assessed throughout the MIT, while performance was assessed as peak power output and time of exercise. Mental fatigue reduced MIT performance (P < 0.05), but CHO mouth rinse was effective to counteract this deleterious mental fatigue effect (P < 0.05). However, we found null effects of CHO mouth rinses in psychological responses above the VT2 (P > 0.05) such as RPE, affective valence, emotional arousal, and motivation. Correlational analysis showed a significant, but moderate negative correlation between motivation and time of exercise above the VT2 when participants used CHO mouth rinse. In conclusion, the ergogenic CHO mouth rinse effects on MIT performance of mentally fatigued cyclists were irrespective of ameliorated psychological responses to exercise.

No Evidence of Postactivation Performance Enhancement on Endurance Exercises: A Comprehensive Systematic Review and Meta-analysis

PURPOSE

Narrative reviews have suggested that postactivation induced by warm-up routines is effective to increase endurance exercise performance in real-world scenarios. However, systematic reviews with meta-analysis rather than narrative ones are required to provide an up-to-date summary of the evidence and provide directions for practical decisions. Therefore, we systematically reviewed peer-reviewed and gray literature to determine the certainty of evidence and the relative effects of postactivation performance enhancement (PAPE) in endurance exercises.

METHODS

The effects of PAPE on endurance performance were meta-analyzed as a standardized mean difference (SMD) from control conditions within a random-effects model considering polled data and subgroups (PAPE strategies, endurance test modalities, and V̇O 2max -based endurance level).

RESULTS

Eligible studies ( n = 35) showed a high risk of bias due to methodological flaws in randomization and blinding procedures. A meta-analysis including 57 comparisons (432 participants) revealed a significant but very small PAPE effect on endurance performance ( Z = 2.49, SMD = 0.15-very small, 95% confidence interval = 0.03 to 0.28) due to exceptional effect sizes reported by two studies (SMD of 2.85 and 2.14). We also observed that neither PAPE strategies nor endurance test modalities or V̇O 2max -based endurance levels influenced the PAPE effects on endurance performance. Meta-regression showed that PAPE effects were correlated neither with the time interval between conditioning routines and endurance exercise nor with endurance exercise duration. We found a very low certainty of evidence that PAPE potentiates endurance performance.

CONCLUSIONS

Based on the analyses of bias and certainty of evidence, we found no support to recommend PAPE strategies to improve endurance exercise performance. Significant but very small PAPE effects on endurance performance were due to two exceptional effect sizes.

Comportamentos de risco para os transtornos alimentares podem reduzir o consumo máximo de oxigênio em ciclistas de estrada?

The aim of this study was to compare the maximum oxygen consumption (VO2max) between road cyclists with and without risk for eating disorders. he sample was composed of 43 cyclists aged 18-25 years, participants of the road cycling championship of the State of Pernambuco. VO2max was measured by a computerized metabolic analyzer during an incremental test in cycleergometer. he initial test load was 50 W, with increments of 25 W every minute until volitional exhaustion or inability to maintain the current load. To evaluate disordered eating behaviors (DEB), the Eating Attitudes Test was used (EAT-26). Univariate analysis of covariance (ANCOVA) was used to compare the VO2max between cyclists with (EAT-26 ≥ 21) and without (EAT-26 < 21) risk for eating disorders. he indings showed statistically signiicant VO2max diference between cyclists with and without risk to eating disorders (F(2, 41)=28.44; p=0.01), indicating moderate effect size (d = 0.6). It was concluded that DEB was related to cyclists with lower VO2max.

Efeito de um período de polimento na potência e capacidade anaeróbia de atletas de tae-kwon-do

DOI: http://dx.doi.org/10.5007/1980-0037.2017v19n2p224 The aim of the study was to analyze the effect of a tapering period on anaerobic power and capacity of tae-kwon-do athletes. Thirty-one male tae-kwon-do participants of the Brazilian Championship were selected in a non-probabilistic way. Subjects were randomly divided into two groups, namely: experimental group (EG, n = 15) and control group (CG, n = 17). Both groups followed the same training protocol up to the tapering stage. CG was submitted to training loads contained in the last two weeks of the macrocycle. Only EG was submitted to tapering. Tapering had 2 weeks duration, adopting the linear tapering method. Taekwondo Anaerobic Test was performed by athletes before the start of the season, which was named as pre-intervention, and the last week of each mesocycle [Prep I, Prep II and Tapering (only EG)]. Group vs. time effect interaction (p < 0.01) was identified for alactic anaerobic power, with an increase only in EG in tapering (p = 0.01). A significant group vs. time interaction (p <0.01) was revealed to fatigue index, improved anaerobic capacity being checked in EG only after the tapering period (p = 0.01). It was concluded that two weeks of linear type tapering optimized the anaerobic power and capacity of male tae-kwon-do athletes.

The effect of fragmentation on phlebotomine communities (Diptera: Psychodidae) in areas of ombrophilous forest in São Luís, state of Maranhão, Brazil

The aim of this study was to determine whether an edge effect could be observed in the structure and composition of phlebotomine assemblages in five forest fragments on São Luís Island. The study also investigated whether there were any differences in species along the forest edge-to-interior gradient and in species richness and abundance between the fragments studied. To capture the insects a transect was defined in each fragment, and eight light traps were set up at 15 m intervals from the edge. Phlebotomines were found in all fragments, and a total of 2972 specimens (1188 males and 1784 females) belonging to 24 species were collected. Of these, the most abundant was Lutzomyia antunesi (Coutinho), followed by Brumptomyia avellari (Costa Lima), L. infraspinosa (Mangabeira), L. flaviscutellata (Mangabeira), L. claustrei Abonnenc, Léger & Fauran, L. wellcomei (Fraiha, Shaw & Lainson), L. sordellii (Shannon & Del Ponte) and L. paraensis (Costa Lima). No significant differences were observed in the number of individuals or species along the edge-to-interior gradient. However, a higher distribution of some species in certain regions of the forest could be observed graphically. There was no correlation between fragment size and the number of species or individuals.