RPE, pain, and physiological adjustment to concentric and eccentric contractions

Purpose: The purpose of the study was to compare perceptual (RPE and pain), cardiac (heart rate), lactate, and endocrine (cortisol) responses with concentric (CON) and eccentric (ECC) resistance exercise protocols using the same absolute workload. Methods: Eight healthy men with resistance-training experience participated in the study. Subjects completed two experimental trials consisting of either CON contractions or ECC contractions at the same absolute workload for each of four exercises: bench press, leg extension, military press, and leg curl. Subjects performed four sets of 12 repetitions at 80% of 10-RM with 90-s rest periods. Blood samples were taken before, immediately after, and 15-min postexercise. Results: There was a significant trial effect for RPE, with CON exercise eliciting a higher RPE than ECC exercise (6.71 +/- 0.51 and 4.10 +/- 0.27, respectively). A significant trial effect was also demonstrated for pain, with CON exercise producing a higher pain rating than ECC exercise (5.59 +/- 0.41 and 3.23 +/- 0.27, respectively). Significantly higher heart rates and lactates were also demonstrated during the CON trial. For cortisol, a significant interaction was revealed between the pre- and immediate posttrial measures but not an overall trial effect. Correlational analyses revealed a significant relationship between RPE and pain for both trials. Conclusions: CON exercise elicits greater perceptual (higher RPE and pain rating). cardiac, lactate and cortisol response than ECC exercise at the same absolute workload. Data demonstrate that relative to absolute load, RPE and pain respond to resistance exercise in a similar fashion. Additionally, physiological cues are consistent with these perceptual data.