RESUMO
Recently, post-exercise blood pressure (BP) has been considered a predictive tool to identify individuals who are responsive or not to BP reductions with exercise training (i. e., "high" and "low responders"). This study aimed to analyze the inter- and intra-individual BP responsiveness following a single bout of high-intensity interval exercise (HIIE) and continuous exercise (CE) in normotensive men (n=14; 24.5±4.2 years). Mean change in BP during the 60 min period post-exercise was analyzed and minimal detectable change (MDC) was calculated to classify the subjects as "low" (no post-exercise hypotension [PEH]) and "high responders" (PEH occurrence) following each exercise protocol (inter-individual analysis). The MDC for systolic and diastolic BP was 5.8 and 7.0 mmHg. In addition, a difference equal/higher than MDC between the exercise protocols was used to define an occurrence of intra-individual variability in BP responsiveness. There were "low" and "high" PEH responders following both exercise protocols (inter-individual variability) as well as subjects who presented higher PEH following a specific exercise protocol (intra-individual variability between exercise protocols). These results were observed mainly for systolic BP. In summary, PEH is a heterogeneous physiological phenomenon and, for some subjects, seems to be exercise-protocol dependent. Further investigations are necessary to confirm our preliminary findings.
Assuntos
Pressão Sanguínea , Exercício Físico/fisiologia , Treinamento Intervalado de Alta Intensidade , Hipotensão Pós-Exercício/diagnóstico , Adulto , Teste de Esforço , Humanos , Masculino , Projetos Piloto , Adulto JovemRESUMO
Low intensity resistance exercise (RE) with blood flow restriction (BFR) has gained attention in the literature due to the beneficial effects on functional and morphological variables, similar to those observed during traditional RE without BFR, while the effects of BFR on post-exercise hypotension remain unclear. The aim of the present study was to compare the blood pressure (BP) response of trained normotensive individuals to RE with and without BFR. In this cross-over randomized trial, eight male subjects (23.8 ± 4 years, 74 ± 3 kg, 174 ± 4 cm) completed two exercise protocols: traditional RE (3 x 10 repetitions at 70% one-repetition maximum [1-RM]) and low intensity RE (3 x 15 repetitions at 20% 1-RM) with BFR. Blood pressure measurements were performed after 15 min of seated rest (0), immediately after and 10 min, 20 min, 30 min, 40 min, 50 min and 60 min after the experimental sessions. Similar hypotensive effects for systolic BP (SBP) were observed for both protocols (P < 0.05) after exercise, with no differences between groups (P > 0.05) and no statistically significant difference for diastolic BP (P > 0.05). These results suggest that in normotensive trained individuals, both traditional RE and RE with BFR induce hypotension for SBP, which is important to prevent cardiovascular disturbances.
RESUMO
The purpose of the present study was to correlate the acute and chronic decrease in blood pressure (BP) following resistance training (RT). 13 normotensive women (18-49 years) completed an acute whole body RT session with 3 sets of 10 repetitions at 60% 1RM and then 8 weeks of RT as follows: 3/week, 3 sets of 8-12 repetitions maximum. Systolic (SBP) and diastolic BP (DBP) were measured up to 60 min and 24 h following RT (acute and chronic). The greatest acute decrease of SBP (108.5±7.0 mmHg) and DBP (71.5±6.4 mmHg) values over the 60-min period were reduced compared to pre-exercise (117.3±11.7 and 79.3±8.2 mmHg, respectively; p<0.05). The chronic effect on resting BP was observed only for those presenting acute post-exercise hypotension (PEH). The change in both SBP and DBP following acute RT was correlated with the chronic change in resting SBP and DBP (r>0.5; p≤0.05). The change in 24 h BP after acute RT was correlated with the chronic reduction in SBP (r=0.74) and DBP (r=0.80). The magnitude of PEH is a promising candidate for the prediction of individual BP-related training efficacy.
Assuntos
Pressão Sanguínea/fisiologia , Ritmo Circadiano , Treinamento Resistido , Adolescente , Adulto , Área Sob a Curva , Feminino , Humanos , Pessoa de Meia-Idade , Força Muscular/fisiologia , Adulto JovemRESUMO
The aim of the present study was to analyse the lactate threshold (LT) changes in rats submitted to an aerobic treadmill-training programme. Twenty-five Wistar rats were divided into two groups: a sedentary control group (CG), and a trained group (TG) submitted to an aerobic training during 5 weeks. All the animals were submitted to an incremental treadmill exercise test in order to determine LT. There was an increase in the maximum running speed in the TG (from 32.25 ± 1.27 to 47.75 ± 3.13 m.min-1 - p = 0.001), and running speed at LT (from 26.21 ± 1.15 to 35.30 ± 2.24 m.min-1 - p = 0.004), a part from the reduction in blood lactate at LT. LT can be determined in rats, and aerobic training induced positive oxidative physiological adaptations in the animals.
Assuntos
Adaptação Fisiológica/fisiologia , Lactatos/sangue , Consumo de Oxigênio/fisiologia , Condicionamento Físico Animal/fisiologia , Corrida/fisiologia , Animais , Masculino , Ratos Wistar , Fatores de TempoRESUMO
The aim of the present study was to compare the acute effects of resistance exercise (RE) designed for hypertrophy or local muscle endurance (LME) on CD4+ and CD8+ T cell apoptosis and migration. 14 untrained subjects (age 20.5±0.8 years, body mass 70.0±12.8 kg, body mass index 24.0±3.2 kg/m(2)), women (N=11) and men (N=3) completed 2 RE sessions (3 sets of 9 exercises) designed for hypertrophy at 10 repetitions maximum (RM) and LME at 60% of 10RM with 1-min rest-intervals between sets and exercises. The investigated lymphocytes were: CD4+, CD4+/CD69RA+, CD8+ and CD8+/CD69RA+ with cell surface markers annexin V and CX3CR1 analyzed by flow cytometry. Percentage of CD4+ positive for annexin V+ were higher immediately following and 24 h after the hypertrophy protocol as compared with LME, while CD4+ positive for CX3CR1 were higher immediately after and lower at the 24 h time point after LME as compared with the hypertrophy session. CD8+ lymphocytes responded similarly to the hypertrophy and LME protocols with elevations in both cellular migration and cell death immediately following and 24 h after the bouts (p≤0.05). Considering that the acute response of CD4+ lymphocytes to RE is protocol-dependent, a gradual adaptation to a hypertrophy program could minimize the effect on CD4+ lymphocytes and reduce the potential susceptibility to antigens during this timeframe. This would also be interesting for a RE program designed for LME based on the observed CD8+ lymphocyte response.