Three Simulated Goalball Games in the Same Day Cause Central Fatigue and Can Impair Game Technical Performance.

The purpose of this study was to investigate the effects of three simulated goalball games on neuromuscular, physiological, perceptual, and technical parameters. Ten male players underwent assessments before and immediately after each game. Heart rate was recorded at rest and during all games that were entirely filmed for further technical performance analysis. Exercise significantly decreased knee extensor muscles peak force and percentage of voluntary activation after the second and third games, indicating the presence of central fatigue. Heart rate responses remained predominantly in a range equivalent to moderate activity intensity in all games. In addition, perceptual parameters were associated with reduced frequency of throws and density of actions. These findings suggest significant implications for the management of physical training, game strategy during a competition, and fixture change from three to two games per day.

Effect of COVID-19 Quarantine on Voice Handicap Index in Female Classical Singers.

OBJECTIVE: This study aimed to verify the impact of vocal deviation in the quality of life of classical female singers over the quarantine imposed by the COVID-19 pandemic through self-assessments. METHODS: Fifty five professional classical female singers filled out an online questionnaire including general questions such as identification, age, professional experience time, vocal classification, time of singing, and rehearsal studies. They all answered the protocol Classical Singing Handicap Index, adapted for this research, which analyses three subscales: Disability, Handicap, and Impairment. RESULTS: There was no significant difference in the perceived total handicap index score (40% of 120 points). Regarding the three domains analyzed, Disability was significantly higher than Impairment (P = 0.012). In addition, the correlation with the variables identified that Impairment subscale showed a negative correlation with the variable hours of rehearsal (r = -0.335, P = 0.040). CONCLUSIONS: The COVID-19 quarantine does not seem to cause a significant impact on the voice of professional classical female singers probably due to their degree of experience and vocal preparation.

Metformin anticipates peak of lactate during high-intensity interval training but no changes performance or neuromuscular response in amateur swimmers.

BACKGROUND & AIMS: Metformin demonstrated potential to improve metabolic efficiency in short-intense and prolonged-continuous efforts. The present study investigates the acute effects of metformin intake on performance, rating of perceived exertion (RPE), blood lactate, blood glucose and neuromuscular parameters related to swimming high-intensity interval series. METHODS: A double-blind, crossover, randomized and placebo-controlled study was carried out. Seven healthy swimmers ingested metformin (500 mg) or placebo capsules on different days and performed a typical high-intensity training series (10 bouts of 50 m with a 3-min interval). Performance, RPE, neuromuscular parameters (lower and upper limbs), blood lactate and glucose were analyzed by the Wilcoxon Signed-Rank and Friedman's tests between supplementation situations and moments, respectively (p > 0.05), the moment where glucose and blood lactate peak were found were analyzed by a Student t-test (p > 0.05) and a Bayesian repeated-measures ANOVA for effects analysis (BFincl). RESULTS: The anticipation of blood glucose and peak lactate was signaling by the interaction effect (metformin increased and placebo decreased) between the eighth and the last bout (BFincl: 4.230 and 5.188 respectively). The second interaction effect of blood glucose and lactate (metformin maintained and placebo increased) during recoveries between 5 min and 7 min (BFincl: 3.825 and 3.806 respectively) also signaling the anticipatory behavior of both physiological parameters. The anticipation of blood lactate peak concentration after metformin intake confirms the anticipatory behavior of blood lactate (p: 0.015). CONCLUSIONS: The anticipatory behavior of glucose was not confirmed. Although the anticipatory peak of blood lactate, metformin does not affect neuromuscular responses, RPE and performance. REGISTRATION OF CLINICAL TRIAL: RBR-67wxdw8 Effects of metformin during swimmer training performance.

Corrigendum: Proposal of a Conditioning Activity Model on Sprint Swimming Performance.

[This corrects the article DOI: 10.3389/fphys.2020.580711.].

Proposal of a Conditioning Activity Model on Sprint Swimming Performance.

This study aimed to propose a conditioning activity (CA) model to stimulate improvement on neuromuscular responses, mechanical parameters and for the 50-m freestyle swimming. Thirteen male swimmers (19 ± 3 years and performances of 77% in relation to World Championship records) performed four CA protocols followed by a maximum performance in the 50-m freestyle. In the first protocol (P1) swimmers performed a standard warm-up (∼15 min); in the second protocol (P2) lunges (3 × 85% of the one-repetition maximum); in the third (P3) pull-ups (3 maximum repetitions) and box jumps 40 cm high and 60 cm deep (1 × 5 with 10% of the corporal weight); and in the fourth protocol (P4) a combination of exercises from the second and third protocols. CA protocols had no effect on the standard warm-up. However, P2 performance (27.01 ± 1.25 s) was similar to P1 (27.01 ± 1.18 s) and presented higher positive effects in mechanical parameters for the swim start performance in comparison to other protocols, contributing to improvements in the 50-m freestyle. In addition, turnaround time also had a negative effect, mainly in P3 (3.12 ± 0.28 s), signaling the improvement of this variable in all protocols (P1: 3.30 ± 0.38 s; P2: 3.17 ± 0.30 s; P4: 3.17 ± 0.34 s). P2 (after: 80 ± 11%; before: 82.7 ± 9.9%) and P3 (after: 82.7 ± 9.9%; before: 85.1 ± 9.7%) presented a possible positive effect on the percentage of voluntary activation in relation to P1 (after: 79.3 ± 10.7%; before: 76.3 ± 12%). In conclusion, the proposed conditioning activity protocols were not efficient for performance improvement in the 50-m freestyle compared to the standard model and seem to specifically influence each phase of the event.

The experience of athletes with disabilities in mainstream sports: an interpretative phenomenological analysis

Abstract Aim: Through reports of the athletes with disabilities interviewed, this study aimed to understand how the experiences lived in mainstream sports occur among people without disabilities. Methods: Husserl's classic phenomenology was the methodological framework adopted. The phenomenological interview was carried out with an intentional sample that included six athletes with some type of physical disability and later its recording was transcribed for the procedures of phenomenological reduction and intentional crossing to explain the meaning of what is experienced by these athletes in mainstream sport. Results: Five categories essentially describe how these experiences occur: operational body barred in the world; shaping the movement; the invisibility of disability; determination stimulus; and normalization of social relations in mainstream sports. These experiences correspond to a dynamic process in which each part does not necessarily follow the other. Conclusion: The experience in mainstream sports allowed the interviewees to improve their experience of capacity, self-efficacy, and recognition through the mutuality between self-perception and the expectation of acceptance by society.