Lucas Tulio Lacerda

The present study evaluated the level of physical activity and physical fitness of users of Family Health Strategy programs in the city of Divinópolis-Minas Gerais, which does not have Physical Education professionals. The 390 users of Family Health Strategy programs participated (145 men and 245 women), aged between 18 and 60 years. They were evaluated regarding their level of physical activity and health aspects, anthropometric measurements, body composition, and physical fitness tests: flexibility (sitting and reaching), muscular resistance (abdominal and arm flexion), and cardiorespiratory fitness. Of the participants, 71% practiced physical activity, good flexibility levels, and muscular strength resistance but had low cardiorespiratory fitness. Regarding body composition, men had a higher fat-free mass and lower body fat compared to women. Besides, 25% are classified as obese, 46% have chronic diseases, 29% are sedentary or irregularly active, 63% have already received instructions to perform physical exercise at health centers, and 99% understand the importance and need for Physical Education Professional in programs. Users practice physical activity but have low cardiorespiratory fitness and body composition due to a lack of targeted physical exercise. Although users receive guidance on practicing physical activity, they understand the need for the presence of a Physical Education professional in programs to perform physical exercise.

Objective: This study analyzed the activation of pectoralis major and triceps brachii muscles in strength tests in bench press after 10 weeks of training. Methods: Thirty-three untrained individuals were divided into two experimental and one-control groups. Protocols were matched by intensity (50-55% of one repetition maximum - 1RM), frequency (3 times a week), pause between sets (3 minutes), number of sets (3 to 4 sets), and time under tension in each set (36 seconds), but with different repetition number and duration (12 repetitions vs. 3seconds / 6repetitions vs. 6seconds). Results: In strength endurance test both experimental groups increased amplitude of Electromyography (EMG) signal in comparison to control group, but with no difference between them. Activation was higher for triceps brachii than for pectoralis major and thus the pectoralis major/triceps brachii activation ratio significantly decreased for both groups, but with no difference between them. In the 1RM and maximum voluntary isometric contraction tests, EMG signal amplitude, activation ratio and analysis of cross-correlation did not exhibited any changes when comparing the experimental and control groups. Conclusion: The results showed that the fact that the protocols used dynamic actions, as well as the same time under tension (TUT), and the differences between single and multiple repetition tests, determined the responses verified.

Tendo em vista os benefícios acerca da prática de atividade física e as problemáticas relacionadas à redução dos níveis dessa prática, faz-se necessário compreender como os fatores motivacionais dos praticantes influenciam nos níveis de adesão e manutenção dessa prática. Esses níveis foram analisados na modalidade CrossFit. O objetivo do estudo foi analisar os aspectos motivacionais que influenciam na prática e permanência no CrossFit, comparando diferentes faixas etárias e frequências de treinamento. Foi realizada uma revisão narrativa qualitativa com objetivo explicativo utilizando as bases de dados Scopus e Web of Science. Foram incluídos 19 artigos, publicados na língua inglesa, considerando o período de publicação delimitado entre os anos de 2000 a 2020. Os resultados demonstram que indivíduos mais jovens sofrem maiores influências de fatores como: afiliação, reconhecimento social e competição, enquanto os mais velhos se motivam mais por motivos de saúde e relacionados ao corpo como controle de peso e aparência. Além disso, a comparação entre as frequências de treino, mostrou que indivíduos independentemente da faixa etária que treinam mais de 5 dias por semana, apresentaram índices mais altos nos fatores intrínsecos, enquanto os que treinam 5 ou menos dias semanais apresentaram maior relação com fatores extrínsecos. Portanto, fatores intrínsecos associados à motivação podem levar a uma maior assiduidade no treinamento de Crossfit.

Objective: The effects of ROM manipulation on muscle strength and hypertrophy response remain understudied in long-term interventions. Thus, we compared the changes in strength and regional muscle hypertrophy after training in protocols with different ranges of motion (ROM) in the seated dumbbell preacher curl exercise using a within-participant experimental design. Design and methods: Nineteen young women had one arm randomly assigned to train in the initial ROM (INITIAL_ROM: 0°–68°; 0° = extended elbow) while the contralateral arm trained in the final ROM (FINAL_ROM: 68°–135°), three times per week over an eight-week study period. Pre- and post-training assessments included one repetition maximum (1RM) testing in the full ROM (0°–135°), and measurement of biceps brachii cross-sectional area (CSA) at 50% and 70% of humerus length. Paired t-tests were used to compare regional CSA changes between groups, the sum of CSA changes at 50% and 70% (CSA_summed), and the strength response between the training protocols. Results: The INITIAL_ROM protocol displayed a greater CSA increase than FINAL_ROM protocol at 70% of biceps length (p = 0.001). Alternatively, we observed similar increases between the protocols for CSA at 50% (p = 0.311) and for CSA_summed (p = 0.111). Moreover, the INITIAL_ROM protocol displayed a greater 1RM increase than FINAL_ROM (p < 0.001). Conclusions: We conclude that training in the initial angles of elbow flexion exercise promotes greater distal hypertrophy of the biceps brachii muscle in untrained young women. Moreover, the INITIAL_ROM condition promotes a greater dynamic strength increase when tested at a full ROM compared to the FINAL_ROM.

Introduction: Neuromuscular performance can be directly affected by a conditioning activity through post-activation potentiation mechanisms. Thus, the conditioning activities are exercises that temporarily improve the organic conditions for the performance in a subsequent physical activity. Objective: To evaluate the effects of post-activation potentiation (PPA) resulting from the own attempts on high-performance performance in horizontal jumps and athletics throws. Methods: This is a quantitative study with retrospective data. The results of 398 finalist athletes from the World Athletics Championships (2018 and 2019) and the Olympic Games (2004 to 2020) were extracted in the male and female modalities of the long jump, triple jump, shot put, discus throw, javelin, and hammer. Only the results of athletes who achieved at least three valid attempts out of a total of six were computed. The information was collected from the official website of the International Athletics Federation (IAAF). The frequencies of the best and worst results between trials were used to assess the effects of trials on the outcome. The significance level for statistical analysis was p<0.05. Results: The best outcome occurred more frequently on trial 3 compared to trials 1, 2, and 4. Better outcomes also occurred more frequently on trial 5 compared to trial 4. The worst trial occurred more frequently on trial 1. Conclusion: The results suggest that the accumulated initial attempts acted as a conditioning activity, which can trigger post-activation potentiation. Introdução: O rendimento neuromuscular pode ser diretamente afetado por uma atividade condicionante através dos mecanismos de potencialização pós-ativação. Dessa forma, as atividades condicionantes são exercícios que melhoram passageiramente as condições orgânicas para o desempenho em uma atividade física posterior. Objetivo: Avaliar os efeitos da potencialização pós-ativação (PPA) decorrentes das próprias tentativas no desempenho de alto rendimento em saltos horizontais e lançamentos do atletismo. Métodos: Trata-se de um estudo quantitativo com dados retrospectivos. Foram extraídos os resultados de 398 atletas finalistas dos campeonatos mundiais de atletismo (2018 e 2019) e dos jogos olímpicos (2004 a 2020) nas modalidades masculina e feminina do salto em distância, salto triplo, arremesso de peso, lançamento do disco, dardo e martelo. Foram computados apenas os resultados dos atletas que conseguiram pelo menos três tentativas válidas de um total de seis. As informações foram coletadas no site oficial da Federação Internacional de Atletismo (IAAF). Foi utilizada as frequências do melhor e pior resultado entre as tentativas para avaliar os efeitos das tentativas sobre o resultado. O nível de significância para diferença estatística foi de p< 0,05. Resultados: O melhor resultado ocorreu com maior frequência na tentativa 3 comparado às tentativas 1, 2 e 4. Melhores resultados também ocorreram com mais frequência na tentativa 5 comparado à tentativa 4. A pior tentativa ocorreu com mais frequência na tentativa 1. Conclusão: Os resultados sugerem que as tentativas iniciais acumuladas atuaram como atividade condicionante, sendo estas capazes de desencadear potencialização pós-ativação.

Objective: To compare the acute effect of two training protocols until concentric failure (CF) with different intra-set interval (ISI) configurations (20 s and 40 s) on total weight, the total number of repetitions, and time under tension in trained subjects. Methods: Ten men participated in the study (age = 25.1 ± 4.4 years; body mass = 76.5 ± 10.4 kg; height = 175.8 ± 9.3 cm). Two protocols were performed with 4 sets of bench press exercises and differentiated by the ISI: i) Protocol ISI-40 (40 s) - each set consisted of 6 repetitions followed by an ISI of 40 s and completed with repetitions up to CF; ii) Protocol ISI-20 (20 s) - each set consisted of 6 repetitions with ISI of 20 s every 3 repetitions followed by repetitions to CF. The intensity was 10 repetitions maximum, and the rest interval between sets of 80 s. A minimum interval of 48 h was adopted between protocols. Results: There was no significant difference in the number of repetitions (p = 0.074), in the time under tension (p = 0.353) and in the total volume (p = 0.083) between the protocols. Conclusion: The results indicate that the different ISI configurations did not distinctly influence the number of repetitions, time under tension, and total volume.

The present study investigated the effect of 10-week matched (range of motion, volume, intensity, rest, and repetition duration) training protocols with varying muscle action duration (MAD) on maximal voluntary isometric contraction (MVIC) test at eight different knee angles and one-repetition maximum (1RM) test after in seated knee extensor machine. Forty women were allocated into one control and three training groups with varying MAD: 5C1E (5s concentric action [CON] and 1s eccentric action [ECC]), 3C3E (3s CON and 3s ECC), and 1C5E (1s CON and 5s ECC). All training groups (5C1E, 3C3E, and 1C5E) showed a greater relative response in 1RM performance than the control group (0.1 ± 3.5%, p ≤ 0.05). The 1C5E group presented greater relative increases in the 1RM performance (22.1 ± 11.6%) compared to 5C1E (13.6 ± 9.2%; p ≤ 0.05) and 3C3E (14.1 ± 5.5%, p ≤ 0.05) groups. The training groups increased the MVIC performance more than the control group (p ≤ 0.05), although there were no significant differences between the training groups. This study demonstrated that isoinertial resistance training protocols with shorter CON MAD showed greater maximum dynamic strength performance response than matched training protocols with other MAD configurations. However, the configuration of MAD did not induce angle-specificity to increase the maximum isometric strength.

The study compared changes in strength and regional muscle hypertrophy between different ranges of motion (ROM) in the knee extension exercise. Forty‐five untrained women were randomized to either a control group or to perform the exercise in one of the following 4 groups (0°=extended knee): Full ROM (FULL_ROM: 100°−30° of knee flexion); Initial Partial ROM (INITIAL_ROM: 100°−65°); Final Partial ROM (FINAL_ROM: 65°−30°); Varied ROM (VAR_ROM: daily alternation between the ROM of INITIAL_ROM and FINAL_ROM). Pre‐ and post‐training assessments included one repetition maximum (1RM) testing in the ROM corresponding to the initial, final and full ROM, and measurement of cross‐sectional areas of the rectus femoris and vastus lateralis muscles at 40%, 50%, 60% and 70% of femur length in regard to regional muscle hypertrophy. Results showed that the INITIAL_ROM group presented a greater relative increase than all groups at 70%, and at 50% and 60% the increases were greater than FINAL_ROM, FULL_ROM, and non‐training control (CON) groups. Moreover, FINAL_ROM group presented similar changes compared to the CON group at 60% and 70%. In regard to 1RM, FINAL_ROM and INITIAL_ROM groups presented greater relative increases at the ROM trained, and no group showed greater increases than VAR_ROM or INITIAL_ROM, regardless the ROM tested. In conclusion, partial ROM training in the initial phase of the knee extension exercise promoted greater relative hypertrophy in certain muscle regions than training in other ROM configurations, and no group promoted a greater 1RM increase than VAR_ROM group, which showed similar 1RM increases in the different ROMs tested.