Guilherme Eckhardt Molina

Heart rate variability (HRV) is a non-invasive tool used to assess autonomic modulation and consequently, welfare of horses under different management conditions. Considering the essential role of horses in equine-assisted therapy, the HRV of seven horses, subjected to a four-month conditioning program was evaluated, using surface electrocardiography. An increase in RMSSD values was noticed, from month 1 (48.83 ms) to month 3 (78.34 ms). In addition, the sympathovagal balance indicated amphotonia in month 1 (SNS: 50.19% and PNS: 49.81%) and vagotonia in month 4 (SNS: 43.56% and PNS: 56.44%), indicating greater vagal predominance over time. These findings may suggest a progressive adaptation of the horses to the environment and conditioning program.

Objectives: To determine whether caffeine supplementation and its expectancy influence muscle strength (ST) and muscle endurance (ME) using a balanced-placebo design. Methods: Using a randomized, double-blind, balanced-placebo design, resistance-trained men (18–30 years; n = 16) participated in two assessment/familiarization visits (demographics; one repetition maximum (1RM) followed by four counterbalanced sessions: C/C (informed caffeine/used caffeine), P/C (informed placebo/used caffeine), C/P (informed caffeine/used placebo), P/P (informed placebo/used placebo). Caffeine dose was 5 mg/kg. Peak torque (PT) and maximum work (MW) were measured in the knee extensors at 0, 60, 180, and 300°/s, which was followed by ME testing (three sets of maximal repetitions using 60%1RM). Capillary blood lactate was measured after ME testing. Results: Caffeine increased PT only during static and 60°/s contractions (4%; p ≤ 0.003; d = 0.3 for both speeds), while MW increased across all speeds (4%; p < 0.001; d = 0.2). Caffeine did not increase ME (3%; p = 0.184; d = 0.1), but it did increase blood lactate levels (1.2 mmol/L; p < 0.001; d = 0.7). Caffeine expectation did not improve ST or ME, but increased blood lactate levels (0.7 mmol/L; p = 0.003; d = 0.4). Across ST and ME, responses to caffeine were markedly heterogeneous, with 50–88% of individuals considered responders (∆ > 0), and improvements in responders ranged from 1–16%. Conclusions: Caffeine significantly increased ST, despite ME increasing in 50% of participants, this was not significant. No placebo effect was observed in ST or ME, but it significantly increased lactate. Further research is necessary to elucidate the mechanisms behind this variability in the ME response, especially the role of fiber-type predominance.

Introduction: The present study sought to expand upon prior investigations of the effect of different training modalities on post-exercise heart rate recovery (HRR) and heart rate variability (HRV). Objective: To compare the HRR and HRV in physically active men with endurance and fitness functional training recreational athletes following maximal treadmill exercise testing. Method: We conducted a cross-sectional study with 53 healthy men split into a control group (CG: n = 15; physically active men), endurance group (EG: n = 16; recreational triathlon athletes), and fitness functional training group (FFG: n = 15; recreational fitness functional training athletes). Short-term (5 min) HRR and HRV indexes (SD1, SD2, and HR/LF) were analyzed in 1-minute segments throughout 5 mins of recovery immediately following maximal treadmill exercise testing. Statistical analysis employed a generalized linear model test with a p -value set at 5%. Results: FFG showed slower HRR than EG at all post-exercise time points (β = − 13.74 to −8.83 bpm; p < 0.01–0.02) and lower HRR than CG at the 1st minute of recovery (β = − 10.47 bpm; p = 0.03). The SD1 (cardiovagal reactivation) was lower in CG than EG at the 1 st (β = − 0.84 ms; p = 0.02); however, no differences ( p > 0.05) existed among all groups throughout the recovery period. The SD2 (overall cardiac autonomic modulation) was lower in FFG than EG at 2nd (β = − 2.51 ms, p = 0.02) and 3rd (β = − 3.20 ms, p = 0.03) minutes. FFG and EG showed higher values of HR/LF index (indicative of sympathetic activity) than CG at the 1 st minute (β = 432.38 to 1,104.49; p < 0.01). FFG also showed higher HR/LF activity than CG an EG at the 2nd and 3rd minutes of recovery (β = 60.48 to 205.31, p < 0.01 to 0.05), and at the 4th minute, than EG (β = 29.33; p = 0.05). Conclusion: HRR was lower in FFG compared to EG throughout recovery. There were no differences in cardiovagal reactivation between the groups from the second to the fifth minute. FFG showed low cardiac overall modulation and high sympathetic activity throughout recovery compared to other groups. These findings may reflect that the FFG displays a persistent coactivation of both autonomic branches following maximal exercise testing compared to the different training modalities.

Background: There is limited understanding of the factors associated with law enforcement officers’ (LEOs’) physical activity levels (PALs) in Latin America. This study aims to address this gap in knowledge. Methods: We analyzed data from a cross-sectional survey among military LEOs from a northern Brazilian state. An anonymous questionnaire, which assessed participants’ PAL using the short version of the International Physical Activity Questionnaires and quality of life (QoL) using the WHOQOL-BREF, was distributed to LEOs. We examined factors associated with PAL with the use of multiple linear regression models. Results: There were a total of 418 participants (38.6± 6.6 years old, 88.3% male). After adjusting for age, sex, role, rank, education, and QoL domains, each unit increase in body mass index (BMI) and the environmental QoL domain were associated with a mean decrease of 56.2 MET-min/week and an increase of 12.8 MET-min/week in PAL, respectively (both P < 0.05). Additionally, those with a college education or higher had a mean PAL increase of 381.1 MET-min/week compared to their counterparts ( P = 0.005). Conclusions : Lower BMI, higher education, and improved environmental QoL are associated with increased PAL among Brazilian military LEOs. Our findings are consistent with existing literature.

Introduction: The Center of Studies of the Physical Fitness Research Laboratory from Sao Caetano do Sul (Centro de Estudos do Laboratório de Aptidão Física de São Caetano do Sul - CELAFISCS) is a research and intervention center with broad national and international recognition. In 2024, CELAFISCS completes 50 years of uninterrupted activity. Objectives: Based on a theoretical essay, our objective was to promote a tribute to the 50 years of CELAFISCS by recovering its main contributions to the Sports and Physical Activity Sciences. Development: The complex task of summarizing the most relevant contributions of CELAFISCS was carried out through documentary analysis and testimonies in three parts: historical aspects, tangible contributions, and intangible ones. Tangible contributions were analyzed considering the scientific production and human resources training done by the members of the successive boards of CELAFISCS during this period. The intangible contributions were analyzed by the impacts of the rapprochement of Brazilian science with the most influential scientists and institutions in the world, of projects to promote physical activity, such as Agita São Paulo, in addition to the social commitment and vision of the future, which are recognized characteristics of CELAFISCS. Final Considerations: Our findings demonstrate that in these 50 years, CELAFISCS has had an equitable distribution by gender, a predominance of physical education professionals, and a high proportion of members involved in research. CELAFISCS has generated highly significant contributions to Sports and Physical Activity Sciences in Brazil, both in academic production and human resources training, justifying the recognition of its essential importance for developing these two significant areas.

Introdução: O Centro de Estudos do Laboratório de Aptidão Física de São Caetano do Sul (CELAFISCS) é um centro de pesquisa e intervenção com amplo reconhecimento nacional e internacional. Em 2024, o CELAFISCS completa 50 anos de atividade ininterrupta. Objetivos: Por meio de um ensaio teórico, objetivou-se prestar uma homenagem aos 50 anos do CELAFISCS, a partir do resgate de suas principais contribuições as Ciências do Esporte e da Atividade Física. Desenvolvimento: A complexa tarefa de sumarizar as mais relevantes contribuições do CELAFISCS foi realizada por meio de análise documental e de depoimentos, em três partes: aspectos históricos, contribuições materiais (tangíveis) e contribuições imateriais (intangíveis). As contribuições materiais foram analisadas à luz da produção científica e formação de recursos humanos pelos membros das sucessivas diretorias do CELAFISCS neste período. Nas contribuições imateriais foram analisados os impactos da aproximação da ciência brasileira com os mais importantes cientistas e instituições do mundo, de projetos de promoção da atividade física, como o Agita São Paulo, além do compromisso social e da visão de futuro, que são características reconhecidas do CELAFICS. Considerações Finais: Os achados demonstram que nesses 50 anos, o CELAFISCS teve distribuição equitativa por gênero, predominância de formação em educação física e elevada proporção de membros com envolvimento com a pesquisa. O CELAFISCS gerou contribuição altamente significativa para as Ciências do Esporte e da Atividade Física no Brasil, tanto na produção acadêmica quanto na formação de recursos humanos, fazendo jus ao necessário reconhecimento de sua essencial importância para o desenvolvimento dessas duas grandes áreas.

Aim: This study evaluated the association between heart rate recovery (HRR) and cardiac parasympathetic reactivation following a submaximal exercise test with resting heart rate (RHR) in the supine and orthostatic positions. Methods: The heart rate (HR), HRR, relative HRR (Δ% HRR), and cardiac parasympathetic reactivation (r-MSSD) values during passive orthostatic recovery at the 1st, 3rd, and 5th min following the submaximal exercise test were correlated with RHR in both the supine (RHRsup) and orthostatic (RHRort) positions in 24 physically active men. The statistical analysis employed Pearson and Spearman correlation tests with a two-tailed p-value set at ≤ 0.05. Results: At the 1st min, HR was significantly correlated with RHRort (r = 0.40; p = 0.05). HR, HRR, and Δ% HRR at the 3rd and 5th min were significantly correlated with RHR (r = from -0.67 to 0.73; p ≤ 0.02; R2 = 32-53%), independent of the body position at rest. At the 3rd and 5th min, the r-MSSD was significantly correlated with RHRsup (r = -0.60, -0.46; p ≤ 0.02). At the 3rd min, the r-MSSD was significantly correlated with RHRort (r = -0.46; p = 0.02). Conclusion: Faster HRR and parasympathetic reactivation on the 3rd and 5th minute after the submaximal exercise test were associated with low RHR in the supine and orthostatic positions in active young men.