Purpose: The purpose of this investigation was to examine selected psychobiological responses to acute bouts of resistance exercise (RE) of different intensities.
Methods: Eighty-four participants were classified as experienced or inexperienced and then randomly assigned to three conditions: 1) 50% of one repetition maximum(1RM), 2) 80% 1RM, or 3) control condition. RE consisted of performing three sets of four exercises between 12 to 20 reps in the 50% 1RM condition and four to eight reps in the 80% 1RM condition. Dependent variables consisted of state anxiety (SA), mood states (POMS), systolic BP (SBP), diastolic BP (DBP), and heart rate (HR). These variables were assessed before as well as 1, 20, 60, 120, and 180-min following the conditions. Data were analyzed with a 2 (experience) x 3 (conditions) x 6 (trials) mixed model ANOVA and Tukey post-hoc tests.
Results: Results indicated that SA decreased significantly (P < 0.05) 180 min following the 50% 1RM condition. A significant decrease (P < 0.05) in vigor occurred immediately following the 50% IRM condition and persisted for 20 min. SBP increased significantly (P < 0.05) immediately following the 80% 1RM condition. HR increased significantly (P < 0.05) following both RE conditions. No significant differences were found between the experienced or inexperienced participants.
Conclusions: An acute bout of RE at 50% 1RM is associated with an immediate reduction in vigor followed by a significant decrease in SA that emerged 180 min following exercise.