Can the inner eye canthus temperature be used as an alternative method to measure core temperature in sleep-deprived individuals?

Core temperature is used in several situations, including studies on biological rhythms and circadian markers of physical performance. Measuring the inner eye canthus (Tco) temperature is a method proposed to identify core temperature, but it has shown little concordance in physical exercise situations and has not yet been used in studies with measurements taken throughout the day. The objective of this study was to compare the measurements and daily behavior of Tco obtained by infrared thermography with rectal temperature (Tre) during a prolonged waking protocol. Eleven male individuals participated in the study, who remained in the laboratory for at least 38 h using an actigraph to determine the wakefulness time and were monitored during the entire period. The Tre and Tco measurements were performed every 3 h. The ANOVA was used for repeated measurements followed by Bonferroni's post-hoc test to find the limits of concordance/proximity, while the Bland and Altman method and the Intraclass Correlation Coefficient were used to establish the reliability between the pairs. The significance level adopted was p < 0.05. The results demonstrate significant differences, low levels of concordance and unsatisfactory reliability levels between Tco and Tre at all 13 analyzed moments, in addition to not showing measurement reliability when all data are used together with the 143 temperature measurements. Daily behavior analysis shows moments with similar behavior with an increase in Tco and Tre, but at other times the behavior was the opposite, with a decrease in one measurement and an increase in the other. Based on the results presented, it is not recommended to use the inner eye canthus temperature as a substitute for rectal temperature for measuring core temperature at different times of the day or in sleep-deprived individuals.

Head pre-cooling improves 5-km time-trial performance in male amateur runners in the heat.

This study aimed to evaluate the effect of head pre-cooling on the 5-km time-trial performance of amateur runners in the heat. In a counterbalanced design, 15 male amateur runners (22.6 ± 3.5 y; VO2 max in heat 42.3 ± 4.4 mLO2 /kg/min) completed two 5-km time trials performed in the heat (35°C, 50% relative humidity). In one trial (HCOOL), participants underwent 20 min of head cooling in a temperate environment (23°C, 70% relative humidity) prior to exercise. In another trial (CON), exercise was preceded by 20 min of rest under the same temperature conditions. Exercise time was shorter in HCOOL (25 min and 36 s ± 3 min) compared to CON (27 ± 3 min; p = 0.02). Rectal temperature was reduced during the pre-exercise intervention in HCOOL (p < 0.001), but not in CON (p = 0.55). Relative changes in rectal temperature and mean head temperature were lower throughout HCOOL when compared with CON condition (p = 0.005 and p = 0.022, respectively). Mean skin temperature, heart rate, and rating of perceived exertion did not differ between HCOOL and CON conditions throughout exercise (p = 0.20, p = 0.52 and 0.31, respectively). Thermal comfort was lower in HCOOL condition in pre-exercise (p = 0.014) with no differences observed throughout exercise (p = 0.61). 5-km running performance in a hot environment was improved after a 20-min head cooling intervention, suggesting that this method may be practical as pre-cooling strategy and easily administered to both professional and amateur runners alike.

Effects of Static and Dynamic Stretching Performed Before Resistance Training on Muscle Adaptations in Untrained Men.

ABSTRACT: Ferreira-Júnior, JB, Benine, RPC, Chaves, SFN, Borba, DA, Martins-Costa, HC, Freitas, EDS, Bemben, MG, Vieira, CA, and Bottaro, M. Effects of static and dynamic stretching performed before resistance training on muscle adaptations in untrained men. J Strength Cond Res 35(11): 3050-3055, 2021-This study evaluated the effects of dynamic and static stretching (SS) performed before resistance training on biceps femoris hypertrophy and knee flexor strength gains in untrained young men. Forty-five untrained young men (age, 21.2 ± 0.5 years; mass, 72.2 ± 5.6 kg; height, 178 ± 1 cm) were randomly assigned to 1 of the 3 groups: (a) 80 seconds of SS (n = 14); (b) 80 seconds of dynamic stretching (DS, n = 13); or (c) control group (CON, n = 18) in which subjects performed no stretching before exercise. Both SS and DS were performed before resistance exercise. Resistance training consisted of 4 sets of 8-12 repetition maximum of seated leg curl exercise 2 days per week for 8 weeks, with a period of at least 48 hours between sessions. Unilateral biceps femoris muscle thickness (MT) and maximal isometric strength (MIS) of the knee flexors were measured 1 week before training and 1 week after the last training session. There were significant increases in MIS (SS = 13.9 ± 10.3 kgf; DS = 10.2 ± 13.1 kgf; CON = 12.7 ± 7.6 kgf; p < 0.05) and MT (SS = 6.0 ± 3.5 mm; DS = 6.7 ± 4.1 mm; CON = 5.7 ± 3.0 mm; p < 0.05) with no significant differences across groups (p > 0.05). Additionally, all groups demonstrated moderate effect sizes for MIS (1.27-1.4), and DS was the only group that had a large effect size for MT increases (DS = 2.18; SS = 1.35; CON = 0.92). In conclusion, 80 seconds of SS and DS did not induce any additional muscular adaptations to resistance training in untrained young men.

Could a Habitual Sleep Restriction of One-two Hours Be Detrimental to the Benefits of Resistance Training?

The absence or decrease in sleep time can affect different mechanisms associated with changes in body composition and physical exercise performance. However, it is unclear in the literature how chronically sleep-restricted individuals respond to strength training. Thus, this study aimed to evaluate the effects of reducing between one and two hours of recommended sleep time (7 hours) on the response to resistance training. The study included 12 subjects who slept on average 2 hours less than the recommended 7 hours per day (42 ± 8 years; 84.9 ± 11.6 kg; 27.9 ± 3.5 kg/m 2 ; 6:17 ± 22 total sleep time/day and 5: 47 ± 29 sleep time/night) and 12 subjects with recommended sleep time (38 ± 11 years; 78.3 ± 9.5 kg; 25.1 ± 3.5 kg/m 2 ; 7:47 ± 38 total sleep time/day and 7:16 ± 54 sleep time/night) and a control group (42 ± 7 years; 81 ± 12.2 kg; 26.2 ± 4.0 kg/m 2 ; 7:30 ± 40 total sleep time/day and 7: 17 ± 51 sleep time/night) that did not perform resistance training. A total of 16 resistance training sessions were performed, 3 times a week (Sessions= 4 exercises; 2 sets; maximum repetitions to failure). The maximum number of repetitions, arm circumference, and arm muscle area increased, while triceps skinfold decreased after training in the experimental groups ( p < 0.05), with no changes for the control group. There was no difference in muscle mass, body mass index, or sleep variables (sleep time, latency, efficiency) after the training period in either group (p> 0.05). Thus, the chronic 1-2-hour reduction in average recommended sleep time was not able to affect the positive effects of resistance training.

Sphingolipid and Trimethylamine-N-Oxide (TMAO) Levels in Women with Obesity after Combined Physical Training.

Obesity causes metabolic changes, such as the development of cardiovascular diseases. Moreover, physical exercise promotes protection against these diseases. Thus, the objective of the present study was to evaluate whether combined physical training can improve the metabolic system of women with obesity, reducing plasma concentrations of trimethylamine N-oxide (TMAO) and sphingolipids, regardless of weight loss. Fourteen obese women (BMI 30-40 kg/m2), aged 20-40 years, sedentary, were submitted to 8 weeks of combined physical training (strength and aerobic exercises). The training was performed three times/week, 55 min/session, at 75-90% maximum heart rate. All participants were evaluated pre- and post-exercise intervention, and their body composition, plasma TMAO, creatinine, lipid profile, and sphingolipid concentrations were recorded. Maximum oxygen consumption (VO2max), Speed lactate threshold 1 (SpeedLT1), and Speed lactate threshold 2 (SpeedLT2) evaluated physical performance. Results: After combined exercise, it did not change body composition, but TMAO, total cholesterol, and sphingolipid concentrations significantly decreased (p < 0.05). There was an increase in physical performance by improving VO2max, SpeedLT1, and SpeedLT2 (p < 0.05). The combined physical exercise could induce cardiovascular risk protection by decreasing TMAO in obese women, parallel to physical performance improvement, independent of weight loss.

Lower head temperature does not affect children's self-paced running velocity.

To test if the use of a peaked cap protects children against sun radiation, allowing increased exercise performance, nineteen healthy children (10.3 ± 0.8 years old, 146.2 ± 6.9 cm, 36.8 ± 5.5 kg, 1.2 ± 0.1 m2 and 44.1 ± 2.8 mL.kg-1.min-1) took part in 4 experimental situations: 2 initial familiarization runs and 2 self-paced 6km runs (4 × 1.5 km exercise bouts with 3min rest intervals) one of them wearing a peaked cap (CAP) and another situation without the cap (NOCAP). The CAP and NOCAP situations were randomized. Exercise was performed outdoors 3-7 days apart. Environmental variables were measured every 10min, and physiological variables were measured before and after each run and during the rest intervals. Running velocity did not differ between CAP and NOCAP situations. The mean head temperature was reduced by 1.1 °C in the CAP situation (p < .05). Average skin temperature, mean heart rate, rate of perceived exertion and wet bulb and globe temperature did not differ between CAP and NOCAP. The decrease in the mean head temperature was not sufficient to alter running velocity.

Sleep extension in athletes: what we know so far - A systematic review.

OBJECTIVE: This study reviewed systematically the effects of sleep extension on sports performance. DESIGN: Systematic review. METHOD: The systematic review was conducted in November 2020. Articles published in English were searched in PubMed, Virtual Health Library, SPORTDiscus, and Web of Science and Scopus databases. The search terms used were "sleep extension" AND athlete. The measures of interest were sports performance. Studies were included if they were a) original articles, b) published in English and peer-reviewed article, c) had only athletes as participants, d) experimental protocol whose objective was to investigate the effects of sleep extension on sports performance, including randomized (RCT) and non-randomized controlled trial (nRCT), and e) at least a sports performance measure as a dependent variable. RESULTS: The primary search revealed that a total of 5 out of 74 articles were considered eligible and 2 studies were subsequently included. The studies used different strategies to extend time in bed or total sleep time (extending 26-106 min). From fifteen sports measures, six presented a large effect size, and the others ranged from trivial to medium. Overall, the risk of bias was high to RCT and low to nRCT and the quality of evidence ranged from very low quality to moderate quality in ten outcomes. CONCLUSIONS: The limited evidence suggests that sleep extension interventions may be beneficial to improve sports performance in athletes where the magnitude is dependent on the variable assessed, although such conclusions are tentative because of the quality of the evidence and risk of bias.

Can IGF-1 Serum Levels Really be Changed by Acute Physical Exercise? A Systematic Review and Meta-Analysis.

BACKGROUND: Physical exercise plays an important role in metabolic health, especially in the insulin-like growth factor-1 (IGF-1) system. The objective of this study was to perform a systematic review and meta-analysis to evaluate the effects of a single endurance and resistance exercise session on IGF-1 serum. METHODS: The systematic review was performed in SPORTDiscus, MEDLINE, PubMed, and Google Scholar databases. All analyses are based on random-effect models. The study identified 249 records of which 21 were included. RESULTS: There was an effect of endurance exercise on total IGF-1 (P = .01), but not for free IGF-1 (P = .36). Resistance exercise similarly only affected total IGF-1 (P = .003) and not free IGF-1 (P = .37). The effect size indicated that total IGF-1 is more affected (ES = 0.81) by endurance than by resistance exercise (ES = 0.46). The present study showed that IGF-1 serum concentrations are altered by exercise type, but in conditions which are not well-defined. CONCLUSIONS: The systematic review and meta-analysis suggest that there is no determinant in serum IGF-1 changes for the exercise load characteristic. Therefore, physical exercise may be an alternative treatment to control changes in IGF-1 metabolism and blood concentration.

How many days are needed for a reliable assessment by the Sleep Diary?

INTRODUCTION: Population sleep registration is important for the epidemiological investigation of possible disorders and diseases associated with sleep deprivation and restriction. The aim of the current study was to verify how many days and weeks are required for a reliable sleep diary application. METHODS: 53 subjects of both genders participated in the study (Age: 25±9 years). The volunteers answered the morning-evening questionnaire for later identification of their chronotype (21 mornings; 22 undetermined; 10 evenings). They then received the sleep diary to fill in for a period of 28 consecutive days (or 4 weeks) of their nighttime sleep. The participant was instructed to describe the time at which they started sleeping and woke up within one hour after waking up. RESULTS: There was no difference in participants' sleep time between weeks. The participants had longer sleep times on Sunday and Saturday compared to other days of the week. The sleep diary reliability values increased with the increasing number of nights, reaching adequate reliability (≥ 0.70) with seven consecutive days recorded. CONCLUSION: A sleep diary seems to be a reliable tool for assessing adult sleep time, especially when used for a period of at least seven consecutive days including weekends.

Which parameters to use for sleep quality monitoring in team sport athletes? A systematic review and meta-analysis.

BACKGROUND: Sleep quality is an essential component of athlete's recovery. However, a better understanding of the parameters to adequately quantify sleep quality in team sport athletes is clearly warranted. OBJECTIVE: To identify which parameters to use for sleep quality monitoring in team sport athletes. METHODS: Systematic searches for articles reporting the qualitative markers related to sleep in team sport athletes were conducted in PubMed, Scopus, SPORTDiscus and Web of Science online databases. The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. For the meta-analysis, effect sizes with 95% CI were calculated and heterogeneity was assessed using a random-effects model. The coefficient of variation (CV) with 95% CI was also calculated to assess the level of instability of each parameter. RESULTS: In general, 30 measuring instruments were used for monitoring sleep quality. A meta-analysis was undertaken on 15 of these parameters. Four objective parameters inferred by actigraphy had significant results (sleep efficiency with small CV and sleep latency, wake episodes and total wake episode duration with large CV). Six subjective parameters obtained from questionnaires and scales also had meaningful results (Pittsburgh Sleep Quality Index (sleep efficiency), Likert scale (Hooper), Likert scale (no reference), Liverpool Jet-Lag Questionnaire, Liverpool Jet-Lag Questionnaire (sleep rating) and RESTQ (sleep quality)). CONCLUSIONS: These data suggest that sleep efficiency using actigraphy, Pittsburgh Sleep Quality Index, Likert scale, Liverpool Jet-Lag Questionnaire and RESTQ are indicated to monitor sleep quality in team sport athletes. PROSPERO REGISTRATION NUMBER: CRD42018083941.

Effects of Different Conditioning Activities on 100-m Dash Performance in High School Track and Field Athletes.

This study compared the effects of different conditioning activities on the 100-m dash performance of 11 male, high school track and field athletes (mean age = 16.3; SD = 1.2 years). Participants performed a 100-m dash seven minutes after each of four randomized conditioning protocols, with each condition and 100-m dash separated by 3-10 days. The conditioning protocols were (a) control, no conditioning activity; (b) weighted plyometric, three sets of 10 repetitions of alternate leg bounding with additional load of 10% of the body mass; (c) free sprint, two 20-m sprints; and (d) resisted sprint (RS), two 20-m resisted sprints using an elastic tubing tool. We obtained session ratings of perceived exertion (SRPE) immediately after each conditioning protocol. There were no significant differences between any of the three experimental conditioning activities on 100-m sprint time, but the RS protocol improved 100-m sprint time compared with the control (no conditioning) protocol ( p < .001). The RS also led to greater sprint velocity and higher SRPE compared with the control condition ( p < .01). There was no significant association between SRPE and 100-m performance ( p = .77, r = .05). These results suggest a benefit for young male track and field athletes to the elastic tubing warm-up activities prior to the 100-m dash.

Effects of different strength training protocols on sarcopenia influencing parameters in older adults: a systematic review / Efeitos de diferentes protocolos de treinamento de força sobre parâmetros influenciadores da sarcopenia em idosos: uma revisão sistemática

INTRODUCTION: Sarcopenia is characterized by the reduction of skeletal muscle mass and its functionality. Several of the parameters that influence sarcopenia are modified by strength training. OBJECTIVE: To review the effects of different strength training protocols (frequency, duration, and intensity) on parameters that influence sarcopenia. METHODS: This is a systematic review of original, quantitative, observational studies, published between 2010 in 2020, in English, Spanish and Portuguese, and indexed in the SciELO, PubMed, and CAPES databases. The terms used search were: "muscle strenght" ("força muscular", "fuerza muscular"), "sarcopenia" ("sarcopenia"), "aging" ("envelhecimento", "envejecimiento"), "olders" ("idosos", "ancianos"), "strength training" ("treinamento de força/resistência", "entrenamiento de fuerza"). 215 articles were retrieved and 11 met the inclusion criteria, being included in the review. RESULTS: Among the 11 studies analyzed, it is observed that strength training applied in different protocols was efficient in improving parameters such as muscle mass and strength, body balance, and performance in diagnostic tests of sarcopenia. CONCLUSION: This review highlights the benefits of the practice of strength exercise in different protocols on parameters that influence the onset of sarcopenia in older adults. The exercise of strength is presented as an applicable, practical, and non-pharmacological means of preventing sarcopenia.

INTRODUÇÃO: A sarcopenia é considerada uma patologia caracterizada pela redução da massa muscular esquelética e da sua funcionalidade, sendo que vários dos parâmetros que influenciam sobre a sarcopenia sofrem interferência do treinamento de força. OBJETIVO: Revisar os efeitos dos diferentes protocolos de treinamento de força (frequência, duração e intensidade) sobre parâmetros influenciadores da sarcopenia. MÉTODOS: Trata-se de uma revisão sistemática de estudos originais, quantitativos, observacionais, publicados entre 2010 a 2020, em inglês, espanhol e português, e indexados nas bases de dados SciELO, PubMed e periódico CAPES. Os descritores utilizados foram: "força muscular" ("muscle strenght", "fuerza muscular"), "sarcopenia" ("sarcopenia"), "envelhecimento" ("aging", "envejecimiento"), "idosos" ("olders, "ancianos"), "treinamento de força/resistência" ("strength training", "entrenamiento de fuerza"). Foram recuperados 215 artigos, entre eles 11 atenderam aos critérios de inclusão, sendo incluídos na revisão. RESULTADOS: Dentre os 11 estudos analisados, observa-se que o treinamento de força aplicado em diferentes protocolos foi eficiente em aperfeiçoar parâmetros como massa e força musculares, equilíbrio corporal e desempenho em testes diagnósticos de sarcopenia. CONCLUSÃO: Esta revisão evidencia os benefícios da prática de exercício de força em diferentes protocolos sobre parâmetros que influenciam na instalação do quadro de sarcopenia em idosos. O exercício de força se apresenta como meio aplicável, prático e não farmacológico da prevenção de sarcopenia.

The sex differences in the 10,000 m race strategy

Abstract Aim: This study aimed to compare the running strategy between men and women in the 10,000 m race. Methods: Data from one-hundred and twenty-nine athletes who competed the 10,000 m final of the 2015, 2017 and 2019 world championship were grouped according to gender: 1) male group (n= 63; age= 25.9±4.4), and 2) female group (n= 66; age= 27.3±4.8). The running strategy was determined by assessing velocity over each kilometer. The velocity was calculated from the times available on the official website of the International Athletics Federation. Results: Men decreased running velocity after the first kilometer and kept the speed stable until km 9 and the kilometer 10 was greater when compared with 6-9 kilometer, while women increase running velocity until km 2 and kept the speed stable until km 9. The kilometer 10 velocity was greater when compared with 1-9 kilometer. (p< 0.001). In addition, women showed a greater average velocity variation when compared to men (p< 0.001). Conclusion: Our findings show a sex differences in the 10,000 m race strategy between world-class.

T-Shirt fabric and color affect the physiological strain but not 10 km outdoor running performance.

BACKGROUND: The aim of the present study was to evaluate the effects of T-Shirt fabric and color on the 10 km outdoor running performance. METHODS: Six men and six women (mean±SD: age: 27±5 years; height: 1.70±0.13 m; weight: 64.0±12.7 kg; body surface area: 1.73±0.29 m2; Σskinfolds: 107±24 mm; VO2max: 40.2±8.4 mL.kg-1.min-1) took part in five experimental trials, during each of which they wore: 1) no T-shirt (CON); 2) white polyester T-shirt (WP); 3) black polyester T-shirt (BP); 4) white cotton T-shirt (WC); and 5) black cotton T-shirt (BC). Average running velocity (pace) was calculated from each 2 km running time. Rectal, skin and T-shirt temperatures, heart rates and Physiological Strain Index (PSI) were measured before and after the 10 km runs and at the end of each 2 km. RESULTS: There were no differences in pace, heart rate, rectal and skin temperatures among conditions (P>0.05). PSI was higher in BC and WC conditions when compared to BP and WP conditions. T-shirt temperature was higher for the BC when compared to WP, BP and WC conditions. Rectal temperature and heart rate increased simultaneously with reduced pace throughout self-paced running (P<0.05). CONCLUSIONS: Despite fabric type T-shirt altered PSI, running performance in the 10 km run was not affected by T-shirt type or color.

Effects of cumulative school soccer matches separated by 24-h or 48-h intervals on physical recovery status of U-19 players / Efeitos de partidas consecutivas de futebol escolar com intervalos de 24 e 48 horas no estado de recuperação física de jogadores Sub-19

Abstract This study aimed to evaluate the effects of cumulative school soccer matches separated by 24-h or 48-h intervals on the recovery status of U-19 players. Thirty-four school athletes (17.6 ± 1.1 years) who played in an U-19 school soccer competition (composed of one group with four teams and another group with three teams, followed by semifinals and final) were examined before three matches, which lasted 70 min. Seventeen athletes had a 24-h rest interval between each match (GGG group), while 18 athletes had a 48-h rest interval between the second and third matches (GG48hG group). Total Quality Recovery, countermovement jump, 10-m sprint, and maximum lumbar isometric strength were measured. The internal load of each match was calculated by the product of the session Rating of Perceived Exertion and match time. There was a 22% reduction in Total Quality Recovery (p< 0.001) and 12% in 10-m sprint performance (p< 0.001) before the third match in the GGG group, while the GG48hG group showed no changes for the same variables (p> 0.05). The countermovement jump decreased before the second match in both groups (GGG= 12% and GG48hG= 10%; p< 0.001), with no difference between groups (p> 0.05). In addition, both groups showed no changes in the isometric strength or the internal load match over the games (p> 0.05). Despite not providing complete muscle recovery, a 48-h interval between the second and third matches seems to have minimized the reduction of muscle performance due to consecutive matches.

Resumo Este estudo teve como objetivo avaliar os efeitos de partidas consecutivas de futebol escolar com intervalos de 24 e 48 horas no estado de recuperação física de jogadores Sub-19. Foram avaliados 35 homens (17,6±1,1 anos) atletas escolares sub-19. Durante a competição, foram realizados três jogos de 70-min de duração. Dezessete atletas tiveram intervalo de 24h entre cada jogo (grupo GGG). Dezoito atletas tiveram intervalo de 48 h entre o 2º e o 3º jogo (grupo GG48hG). Antes de cada jogo foram medidas a Qualidade Total de Recuperação, altura do salto com contra movimento, velocidade no sprint de 10-m, e força máxima isométrica lombar máxima. A carga interna do jogo foi calculada pelo produto da percepção subjetiva do esforço da sessão e tempo de cada jogo. Houve uma redução de 22% na qualidade total de recuperação (p <0,001) e de 12% no desempenho de sprint de 10 m (p <0,001) antes da terceira partida no grupo GGG, enquanto o grupo GG48hG não apresentou alterações para as mesmas variáveis (p> 0,05). O salto com contra movimento diminuiu antes da segunda partida em ambos os grupos (GGG = 12% e GG48hG = 10%; p <0,001), sem diferença entre os grupos (p> 0,05). Em adição, ambos os grupos não apresentaram alterações na força isométrica e na carga interna ao longo dos jogos (p> 0,05). Apesar de não proporcionar uma completa recuperação muscular, 48 h de intervalo entre o segundo e o terceiro jogo parece ter minimizado o efeito de jogos consecutivos na redução do desempenho.

Efeitos cognitivos do teste de esforço progressivo em eletricistas com equipamentos de proteção individual / Cognitive effects of the progressive exercise test in electricians wearing personal protective equipment

Resumo Objetivo: verificar o efeito do esforço físico sobre as funções cognitivas de trabalhadores eletricistas utilizando equipamento de proteção individual (EPI). Métodos: participaram 28 eletricistas que trabalhavam na construção, manutenção e operação de redes de distribuição de energia. Todos do sexo masculino, sadios e aptos para a prática de exercícios físicos. As funções cognitivas foram representadas pelo teste de reação simples (TRS) e pelo nível de vigilância mental (NVM). O TRS e o NVM foram mensurados pré e pós-teste máximo progressivo, em esteira rolante, a 27 °C de temperatura seca e umidade relativa do ar de 64%. O teste consistiu em aumentos progressivos na velocidade e na inclinação da esteira até a fadiga, com utilização de EPI. Resultados: a média (desvio padrão) do TRS não foi significativamente diferente antes, 227,8 (35,1) ms, e após o exercício, 220,6 (24,6) ms. O NVM foi significativamente maior após o exercício em todas as situações: frequência crescente - 36,5 (5,1) Hz vs 39,5 (2,7) Hz, frequência decrescente - 36,0 (5,2) vs 39,0 (3,88) Hz, e frequência geral - 36,2 (4,9) vs 39,2 (3,1) Hz. Conclusão: o exercício progressivo máximo realizado com EPI não modificou o tempo de reação simples e aumentou o nível de vigilância mental de eletricistas.

Abstract Objective: to verify the effects of physical effort on the cognitive functions of electricians wearing personal protective equipment (PPE). Methods: 28 electricians participated. They worked on the construction, maintenance and operation of electrical power distribution networks. All were male, healthy and able to practice physical exercises. The cognitive functions were checked by measuring simple reaction time (SRT) and mental alertness level (MAL). SRT and MAL were measured before and after progressive maximal exercise, on a treadmill, at 27 °C dry temperature and 64% relative humidity, wearing PPE. The test consisted of progressive increases in treadmill speed and incline, until fatigue. Results: SRT mean difference was not significantly different before - 227.8 (35.1) ms - and after exercising -220.6 (24.6) ms. MAL was significantly higher after exercise in all situations: increasing frequency - 36.5 (5.1) Hz vs. 39.5 (2.7) Hz; decreasing frequency-36.0 (5.2) Hz vs. 39.0 (3.88) Hz; and general frequency 36.2 (4.9) Hz vs. 39.2 (3.1) Hz. Conclusion: progressive maximal exercise performed while wearing PPE caused no change in simple reaction time, and increased electricians' mental alertness level.

Effect of a school soccer competition with consecutive day games on the recovery status of U-19 players / Efeito de uma competição escolar de futebol com jogos em dias consecutivos no estado de recuperação de jogadores sub-19

Abstract The present study aimed to evaluate the effect of a school soccer competition with consecutive day games on the recovery status of U-19 players. Thirty-one school athletes (17.1±1.1 years) who played a U-19 school soccer competition (composed of two groups of four soccer teams each, followed by semifinals and final) were randomly evaluated. Games lasted 70 min (two periods of 35 min with 15 min rest interval), and they were played on consecutive days with 24 h between each game. Delayed onset muscle soreness (DOMS) and Total Quality Recovery (TQR) were measured before group phase games (n= 31) and semifinals games (n= 18). The internal game load was measured by the session rate of perceived exertion (session-RPE) method. TQR was higher before the first game when compared to the other games (p< 0.001). DOMS increased after the first game and did not return to baseline before the fourth game. Both session-RPE and internal load of the fourth game were higher than in the other games (p< 0.001). In addition, there was no correlation between internal game load and TQR (p> 0.05). The monotony observed during the evaluated period was 3.1±2.0 AU. The results indicate that the 24 h rest period seems to be insufficient for complete recovery of U-19 soccer school athletes, suggesting the organization of U-19 school soccer competitions with higher rest interval between games and search for methods to increase the recovery rate.

Resumo O presente estudo objetivou analisar o efeito de uma competição escolar de futebol com jogos em dias consecutivos no estado de recuperação física de jogadores sub-19. Foram avaliados, de forma aleatória, 31 atletas escolares (17,1±1,1 anos) participantes de uma competição escolar de futebol de campo sub-19, composta de duas chaves com quatro equipes cada, seguido de semifinais e final. Os jogos tiveram 70 min de duração (dois tempos de 35 min com 15 min de intervalo), e foram realizados em dias consecutivos com intervalo de 24h entre cada jogo. Foi medida a dor muscular de início tardio (DOMS) e Qualidade Total de Recuperação (QTR) antes de cada jogo da primeira fase (n= 31) e da semifinal (n=18). A carga interna dos jogos foi medida a pelo método da percepção subjetiva do esforço da sessão (PSE-sessão). A QTR foi maior antes do primeiro jogo em comparação com os demais jogos (p< 0.001). A DOMS aumentou após o primeiro jogo e não retornou aos valores basais antes do quarto jogo (p< 0.001). A PSE-sessão e a carga interna do quarto jogo foram maiores que as dos demais jogos (p< 0,001). Em adição, não houve correlação entre a carga interna do jogo e a QTR (p> 0,05). A monotonia encontrada no período avaliado foi de 3,1±2.0 UA. Os resultados indicam que o período de 24h parece ser insuficiente para a completa recuperação de atletas escolares de futebol sub-19, sugerindo a organização de competições escolares de futebol sub-19 com maior intervalo entre os jogos e busca por métodos que acelerem a recuperação.

Bench press exercise performed as conditioning activity improves shot put performance in untrained subjects

The aim of the present study was to evaluate the effect of bench press exercise performed as conditioning activity on the shot put performance in untrained subjects. Methods: Twelve healthy men (26 ± 6 years; 1.8 ± 0.1 m; 73.5 ± 10.4 kg; 13.2 ± 5.2% body fat), with no experience in shot put, were randomly assigned into two conditions: 1) Control: subjects performed six shot put attempts, and 2) Bench press exercise: subjects performed six shot put attempts 7 min post 2 sets of 5 repetitions maximum (RM) of bench press exercise. A metal ball of 4 kg was used for shot put attempts, and subjects were instructed to perform each shot put according to the static shot put technique. Results: Shot put performance was greater after bench press condition when compared with control condition (8.2 ± 1.2 m vs. 7.8 ± 0.8 m, respectively, p < 0.05). In addition, eight out of 12 volunteers positively responded to the conditioning activity. Conclusion: The results suggest that bench press exercise performed as a conditioning activity improves shot put performance in untrained subjects. Moreover, the conditioning activity should be individually set.(AU)

Effect of post-activation potentiation in Athletics: a systematic review / Efeito da potencialização pós-ativação no Atletismo: uma revisão sistemática

Abstract Post-activation potentiation is a physiological phenomenon reported to increase muscle performance during high-intensity exercise. To induce post-activation potentiation, maximal strength or power short-duration activities are performed minutes prior the main activity in an attempt to enhance performance. The aim of this study was to evaluate previous publications on the effects of post-activation potentiation on athletic performance. This systematic review used Scielo, Pubmed and SporDiscus database with the following search terms either alone or grouped together: post-activation potentiation, exercise, athletics, track and field, sprint, long jump, triple jump, high jump, shot put, javelin throw, hammer throw e discus throw. The review provided evidence that performing squat, jump and sprint exercises prior to the main activity elicited a state of potentiation that would improve sprint and throw performances and that preparatory activities that can cause post-activation potentiation should be used to improve athletic performance.

Resumo A potencialização pós-ativação é um fenômeno fisiológico capaz de aumentar o desempenho muscular durante exercícios de alta intensidade. Para induzir a potencialização pós-ativação, atividades de curta duração com força máxima ou potência muscular são realizadas minutos antes da atividade principal na tentativa de aumentar o desempenho. O objetivo deste estudo foi avaliar as publicações anteriores sobre os efeitos da potencialização pós-ativação sobre o desempenho no atletismo. Esta revisão sistemática utilizou os bancos de dados Scielo, Pubmed e SportDiscus com os seguintes termos de pesquisa juntos ou separados: post-activation potentiation, exercise, athletics, track and field, sprint, long jump, triple jump, high jump, shot put, javelin throw, hammer throw e discus throw. A revisão evidenciou que a realização de agachamentos, saltos e sprints, antes da atividade principal, desencadeia o estado de potencialização, que então aumenta o desempenho de sprints e lançamentos, e que atividades preparatórias que causam potencialização pós-ativação podem ser utilizadas para aumentar o desempenho no atletismo.

Qual a contribuição das características antropométricas na velocidade de corrida de curta distância? / What is the contribution of anthropometric characteristics on sprint run? / Qué es la contribución la características antropométricas en la carrera de velocidad

O estudo buscou avaliar os efeitos das características antropométricas na velocidade de corrida. Foram avaliados a estatura, massa corporal (MC), índice de massa corporal (IMC), dobra cutânea panturrilha (DCpa), comprimento da tíbia (Ctíbia) e velocidade da corrida (50m) de 235 estudantes. A análise de regressão múltipla explicou 62% do desempenho na corrida (p<0,05). A análise de regressão linear simples mostrou que a DCpa correspondeu a 45%, estatura 33%, Ctíbia 24% e MC 3%, do desempenho na corrida (p<0,05). A análise de cluster mostrou que o grupo de baixa velocidade apresentava maior MC, IMC e DCpa (p<0,05), e o grupo de alta velocidade apresentava maior estatura, Ctíbia e menor DCpa (p<0,05). Conclui-se que as medidas antropométricas podem predizer o desempenho da corrida.

The aim of this study was to determine the effects of anthropometric characteristics on sprint. It was measured the height, body mass (BM), body mass index (BMI), calf skin fold (CKF), tibia's length (TL) and running velocity (50m) of 235 students. The multiple regression explain 62% of 50 m running performance (p<0.05). The simple linear regression showed that CKF represented 45%, height 33%, TL 24%, and BM 3% of 50m running performance (p<0.05). The cluster analyze showed that the low velocity group presented highest BM, BMI and CKF (p< 0,05), while the high velocity group presented the highest stature, TL and the lowest CKF (p< 0,05). The results suggest that anthropometric variables used in the current study can significantly predict the 50 m sprint in young people.

El estudio trata de evaluar los efectos de las características antropométricas en la carrera de velocidad. Fue evaluado la altura, masa corporal (MC), índice de masa corporal (IMC), pliegue cutáneo del pantorrilla (DCpa), longitud de la tibia (Ctíbia) y la carrera de velocidad (50m) de 235 estudiantes. El analisis de regresión múltiple explica el 62% del rendimiento en la carrera (p <0,05). El análisis de regresión lineal simple mostró que correspondía a 45% DCpa, 33% altura, 24% Ctíbia y 3% MC, el rendimiento en la carrera (p <0,05). El análisis de conglomerados mostró que el grupo de baja velocidad tuvo un mayor MC, DCpa y el IMC (p <0,05), y el grupo de alta velocidad mostró una mayor altura, Ctíbia, e inferior DCpa (p <0,05). Se concluye que las medidas antropométricas puede predecir el rendimiento de la carrera.