BackgroundPost-activation potentiation (PAP) is the phenomenon by which muscular performance is enhanced in response to a conditioning stimulus. PAP has typically been evidenced via improved counter movement jump (CMJ) performance. This study examined the effects of PAP, with and without prior caffeine ingestion, on CMJ performance.MethodsTwelve male professional soccer players (23 ± 5 years) performed two trials of plyometric exercises and sled towing 60 min after placebo or caffeine ingestion (5 mg.kg− 1) in a randomized, counterbalanced and double-blinded design. CMJ performance was assessed at baseline and 1, 3 and 5 min after the conditioning stimulus (T1, T3 and T5, respectively).ResultsTwo way ANOVA main effects indicated a significant difference in jump height after the PAP protocol (F[3, 11] = 14.99, P < 0.001, partial η2 = 0.577). Analysis also indicated a significant difference in CMJ performance across conditions, with caffeine eliciting a greater response (F[1, 11] = 10.12, P = 0.009, partial η2 = 0.479). CMJ height was increased at T1, T3 and T5 in caffeine condition (5.07%, 5.75% and 5.40%, respectively; P < 0.01) compared to baseline. In the placebo condition, jump performance was increased at T3 (4.94%; P < 0.01) only. Jump height was higher in caffeine condition on T1, T3 and T5 (P < 0.05) but not on baseline (P > 0.05) compared to placebo.ConclusionsThe results of this study suggest that acute plyometric and sled towing stimuli enhances jump performance and that this potentiation is augmented by caffeine ingestion in male soccer players.

The aim of this study was to evaluate the acute effects of high-intensity eccentric exercise (HI-ECC) combined with blood flow restriction (BFR) on muscle damage markers, and perceptual and cardiovascular responses. Nine healthy men (26 ± 1 years, BMI 24 ± 1 kg m ²) underwent unilateral elbow extension in two conditions: without (HI-ECC) and with BFR (HI-ECC+BFR). The HI-ECC protocol corresponded to three sets of 10 repetitions with 130% of maximal strength (1RM). The ratings of perceived exertion (RPE) and pain (RPP) were measured after each set. Muscle damage was evaluated by range of motion (ROM), upper arm circumference (CIR) and muscle soreness using a visual analogue scale at different moments (pre-exercise, immediately after, 24 and 48 h postexercise). Systolic (SBP), diastolic (DBP), mean blood pressure (MBP) and heart rate (HR) were measured before exercise and after each set. RPP was higher in HI-ECC+BFR than in HI-ECC after each set. Range of motion decreased postexercise in both conditions; however, in HI-ECC+BFR group, it returned to pre-exercise condition earlier (post-24 h) than HI-ECC (post-48 h). CIR increased only in HI-ECC, while no difference was observed in HI-ECC+BFR condition. Regarding cardiovascular responses, MBP and SBP did not change at any moment. HR showed similar increases in both conditions during exercise while DBP decreased only in HI-ECC condition. Thus, BFR attenuated HI-ECC-induced muscle damage and there was no increase in cardiovascular responses.

The main purpose was to investigate whether the perception of effort during the two first repetitions of strength exercises could be an adequate strategy for estimating the strength-training zone. The sample comprised 11 women (18 to 35 years-old). In the first week, the volunteers performed a 1-RM test in seven exercises on strength machines, and the load was calculated to reach 50%, 70% and 90% of the 1-RM. Over the next three weeks, the volunteers were required to perform randomly the exercises at these three intensities. After the two first repetitions, the volunteers were questioned about how many repetitions they believed they could achieve until failure (self-estimated). Additionally, volunteers were asked to indicate their exertion according Borg scale. After volunteers performed every exercise until concentric failure to complete the repetition maximum test (RMs test). The data were analyzed using linear regression, Pearson correlation and paired t-test. The results showed that the self-estimated number of repetitions underestimated 44% and 30% of the mean values of repetition maximum obtained directly at intensities of 50% and 70% (p < 0.05), respectively. Although repetition maximum were correlated with Borg scale (r = -0.23 to -0.41; p < 0.05) and self-estimated number of repetitions (r = 0.25 to 0.41; p < 0.05), the standard errors of estimate obtained by linear regression were very high (40% to 49%), which prevented any estimation equations. In conclusion, the perception of effort during the two first repetitions is not a satisfactory strategy for estimating the strengthtraining zone.

Mixed martial arts (MMA) is a combat sport where competitors utilize strikes (punches, kicks, knees, and elbows) and submission techniques to defeat opponents in a cage or ring. The aim of this study was to investigate the effect of acute caffeine ingestion on punching performance by professional MMA athletes. The study used a double-blind, counterbalanced, crossover design. Eleven professional MMA competitors (27.6 ± 4.3 years and 83.5 ± 7.8 kg of body weight) ingested a dose of caffeine (5 mg·kg−1) or placebo 60 min prior to three sets of punching. Each set consisted of 15 s, at which participants were asked to perform straight punches with maximum strength and frequency with his dominant arm. After each set, a 45 s recovery time was applied. Using a force transducer attached to a cushioned plate, the punch frequency, and mean and maximal punch force was measured. The readiness to invest in both physical (RTIPE) and mental (RTIME) effort was assessed prior to the protocol, and the rating of perceived exertion (RPE) was recorded after. Caffeine ingestion did not result in increased punching frequency, mean and maximum punch force, RTIPE, RTIME, and RPE when compared to the placebo condition. Based on these results, acute caffeine ingestion did not improve punching performance in professional MMA athletes.

To investigate the relationship of the response to postactivation potentiation (PAP) with scores of physical fitness. Twenty-four professional male soccer players undertook tests of agility, muscular power, aerobic capacity, and body composition. Conditioning activities (CAs) were performed consisting of plyometrics exercises and sprints with sled towing. In the first and second sessions, body composition, agility, power, and aerobic capacity were assessed. At the third session, countermovement jumps (CMJ) were performed with 1, 3, and 5 minutes after the execution of the CA. Significant differences were found for CMJ height 1, 3, and 5 minutes after the CA compared with baseline values (3.58, 5.10, 5.48%, respectively). There was a significant positive correlation between the level of general physical fitness and PAP (CMJ height increase) 5 minutes after (r 5 0.73). When the athletes were divided into groups with higher and lower physical fitness, the CA caused a significant increase in CMJ height in both groups, but a significant difference (p , 0.05) was observed at all times after PAP induction, with better performance in higher versus lower fitness level. The results suggest that plyometrics exercises associated with sled towing sprints as a CA result in an increase in CMJ performance in athletes and that physical fitness directly influences the PAP occurrence, with higher fit players demonstrating an enhanced PAP response.

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Resumo Dentre as categorias que fazem parte da força de trabalho do SUS está a Educação Física. Por meio de estudo ecológico de séries temporais, com base no Cadastro Nacional de Estabelecimentos de Saúde, os objetivos do artigo foram analisar a inserção de Profissionais de Educação Física (PEF) e residentes no SUS entre 2009 e 2021 com vistas a traçar um panorama da inserção da Educação Física e analisar a distribuição de PEF e residentes entre as diferentes regiões. Foi revelado um aumento de 476,01% no número de PEF e de 10.366,67% entre os residentes. A taxa de PEF por 100.000 habitantes aumentou 13,7% ao ano entre 2009 e 2021, com aumento de 28,1% entre 2009 e 2014 e de 7,8% entre 2014 e 2019, e redução de 3,4% entre 2019 e 2021. A taxa de residentes aumentou 36,2% ao ano entre 2009 a 2021, com aumento de 45,9% entre 2009 e 2017 e de 18,7% entre 2017 e 2021. Foram reveladas desigualdades regionais na distribuição de PEF e residentes, com maior concentração, em 2021, respectivamente nas regiões Nordeste e Sul. O aumento de PEF e residentes no SUS pode ser relacionado com políticas e programas de práticas corporais e atividades físicas, enquanto o decréscimo, possivelmente, se relaciona com o Programa Previne Brasil e à pandemia de COVID-19.

Resumo Considerando a inserção de Profissionais de Educação Física como força de trabalho no Sistema Único de Saúde, este estudo teve como objetivo analisar os tipos de vínculos e a carga horária de trabalho desses profissionais nos diferentes níveis de atenção à saúde e regiões do Brasil entre 2007 e 2021. Trata-se de um estudo descritivo de abordagem quantitativa com base em pesquisa no Cadastro Nacional de Estabelecimentos de Saúde. Foi observado que a atenção primária à saúde constitui o principal nível de atuação, seguida da atenção secundária e terciária. Na atenção primária, o número de cadastros de Profissionais de Educação Física com vínculo de trabalho precário é maior do que os com vínculo protegido, mas o inverso ocorre na atenção secundária e terciária. Nas regiões Sul e Sudeste, foi revelado maior número de cadastro desses profissionais com vínculo de trabalho protegido, e nas demais regiões prevaleceu o vínculo de trabalho precário. Foi identificado que 44,7% dos cadastros de Profissionais de Educação Física possuem carga horária maior ou igual a 40 horas por semana. Em conclusão, a atenção à saúde pode ser prejudicada pelo tipo de vínculo de trabalho do profissional por causar rotatividade e dificuldade na continuidade do cuidado.