OBJECTIVE: To analyze the influence of previous aerobic exercise on cardiovascular responses during resistance exercise.
METHODS: This is a crossover observational study. The sample included 19 normotensive men aged between 19 and 39 years. Subjects performed two experimental sessions in random order: resistance exercise (R: three sets of knee extension exercises with 40% of one repetition maximum) and aerobic exercise+resistance exercise (A+R: 30min of aerobic exercise followed by R protocol). In both sessions, blood pressure (BP) and heart rate were monitored beat-by-beat by finger photoplethysmography.
RESULTS: After aerobic exercise in the A+R session, there was a maintenance of systolic BP -2 (95% CI: -6; 2) mmHg (P=0.35), diastolic 1 (95% CI: -2; 5) mmHg (P=0.40) and mean BP 0 (95% CI: -4; 4) mmHg (P=0.91) and an increase in heart rate 11 (95% CI: 7; 16)bpm (P<0.001). Diastolic and mean BP increased and peak heart rate was higher during resistance exercise in the A+R session compared to the R session. Differences between sessions: diastolic BP 7 (95% CI: 2; 12) mmHg (P=0.03); mean BP 8 (95% CI: 2; 13) mmHg (P=0.05); and peak heart rate 18 (95% CI: 13; 23)bpm (P<0.001). The increases in systolic BP during resistance exercise were similar between sessions 16 (95% CI: 6; 26) mmHg (P=0.43).
CONCLUSION: Aerobic exercise before resistance exercise increased diastolic and mean BP and heart rate. However, due to the sample size of 19 individuals, the results must be interpreted with caution.