Bruno Remígio Cavalcante

Intra-individuals and inter- and intra-observer reliability of short-term heart rate variability in adolescents

To examine the reliability of heart rate variability (HRV) parameters in adolescents and to analyse the inter‐ and intra‐observer reliability of data analysis.

Effects of active recovery on autonomic and haemodynamic responses after aerobic exercise

The aim of this study was to examine the effect of active recovery on autonomic and haemodynamic responses after exercise in healthy adults. Nineteen healthy young male individuals underwent two experimental sessions: exercise with active recovery (AR) and exercise with passive recovery (PR). The exercise sessions comprised three phases: warm‐up (5 min), exercise phase (cycle ergometer, 30 min, intensity between 60 and 70% of the heart rate reserve) and recovery (5 min). In the AR, the subjects remained cycling in the recovery phase at intensity between 30% and 35% of heart rate reserve, while in the PR, the subjects stopped the exercise after finishing the exercise phase. Blood pressure and heart rate were measured before and over the 30 min after the interventions. There were no differences for systolic and diastolic blood pressures, heart rate and rate pressure product between active and passive recovery sessions. Also, all heart rate variability parameters changed similarly after exercise with passive or active recovery sessions. In summary, exercise with active recovery does not affect the autonomic and haemodynamic responses after moderate‐intensity aerobic exercise in healthy young male individuals.

Motor cortex tDCS does not modulate perceived exertion within multiple-sets of resistance exercises

BACKGROUND: Recent evidences have shown that the motor cortex (MC) may influence the rating of perceived exertion (RPE). Given the potential role of transcranial direct current stimulation (tDCS) in modulate cortical areas related to exercise performance, it is possible that tDCS applied on motor cortex (MC) could also influence the RPE during resistance exercises. OBJECTIVE: This study analyzed the effects of transcranial direct current stimulation on the rating of perceived exertion during multiple sets of resistance exercises. METHODS: Thirteen strength-trained men performed a resistance exercise session after either anodal tDCS or sham stimulation applied over the primary motor cortex. Resistance exercise sessions included 3 sets of 10 repetitions of 6 exercises performed with load of at 85% of 8–12 RM. The RPE was obtained using OMNI-Resistance exercise scale. RESULTS: The RPE assessed at the end of the sessions was similar in tDCS vs. sham condition (6.78 ± 1.48 vs. 6.87 ± 1.49, respectively; p = 0.56). The RPE for each exercise was similar across conditions, except for the second set of bench press (p = 0.04) and first set of seated-row (p = 0.03). CONCLUSION: In conclusion, the RPE during multiple sets of submaximal exercises was not modulated by tDCS applied upon

ASSOCIAÇÃO ENTRE A ATIVIDADE FÍSICA DE LAZER E DE DESLOCAMENTO COM A VARIABILIDADE DA FREQUÊNCIA CARDÍACA EM ADOLESCENTES DO SEXO MASCULINO

ABSTRACT Objective: To investigate the association between heart rate variability (HRV) parameters with leisure time and commuting physical activities in adolescent boys. Methods: The sample included 1152 male adolescents aged 14 to 19 years. The variation of consecutive heart beats (RR intervals) was assessed and HRV parameters in time (SDNN, RMSSD, pNN50) and frequency domains (LF/HF) were calculated. Leisure time and commuting physical activities were obtained using a questionnaire. A binary logistic regression was performed between HRV parameters and physical activity. Results: Leisure time physical activity was associated with SDNN, RMSSD, pNN50, while LF/HF was not associated. These associations were stronger when adolescents were also physically active for more than six months. Commuting physical activity was not associated with any HRV parameter. Boys who practiced commuting physical activity and were also physically active for more than six months presented a lower chance of having low SDNN and RMSSD. Conclusions: Leisure time physical activity was associated with better HRV and these associations were enhanced when adolescents were physically active for more than six months. Commuting physical activity was not associated with HRV parameters; however, it became associated with better HRV when adolescents were physically active in commuting for more than six months.

Hemodynamic and autonomic responses after a single session of resistance exercise following anodal motor cortex tDCS

BACKGROUND: Transcranial direct current stimulation (tDCS) seems to modulate cardiac autonomic function and blood pressure (BP) at rest and during exercise. Therefore, it is possible that anodal tDCS could influence post-exercise hypotension. OBJECTIVE: To investigate whether anodal tDCS applied over the motor cortex would affect cardiac autonomic modulation and BP after resistance exercise. METHODS: Twelve apparently healthy young men performed two experimental sessions: anodal tDCS or sham condition followed by resistance exercise. Blood pressure (BP), heart rate (HR), rate-pressure product (RPP), and HR variability (HRV) were obtained before and during post-exercise recovery (at 20 and 60 minutes). RESULTS: Compared to pre-exercise, systolic BP decreased at 20 and at 60 minutes of post-exercise recovery only in anodal tDCS condition (p = 0.03), with no statistical differences in sham condition (p > 0.05). Diastolic and mean BP reduced after both anodal tDCS and sham conditions with no differences between them (P> 0.05). In comparison with anodal tDCS, there were slower HR recovery (tDCS vs. sham: -2 ± 14 vs. 14 ± 8 bpm) and higher RPP (tDCS vs. sham: -1083 ± 1846 vs. 1672 ± 1275 mmHg × bpm) after exercise following sham condition (P 0.05). CONCLUSION: A single session of primary motor cortex tDCS is capable of decreasing the systolic BP and HR responses, as well as the cardiac work after a resistance exercise session in young normotensive subjects regardless of any changes in cardiac autonomic modulation.