The Acute Physiological Responses of Eccentric Cycling During the Recovery Periods of a High Intensity Concentric Cycling Interval Session

Eccentric and concentric exercise is associated with disparate acute and chronic responses. We uniquely interspersed workload equivalent eccentric cycling during each recovery period of a high intensity interval training (HIIT) cycling trial to determine acute cardiopulmonary, thermal and psycho-physiological responses. Twelve males [age 28 years (SD 6), peak oxygen consumption 48 mL . kg(-1) . min(-1) (SD 6)] completed two high intensity interval cycling trials [4 x 5 min, 60% peak power output (PPO)] separated by 7-10 days. The CONR trial required participants to cycle concentrically during each recovery period (5 min, 30% PPO). The ECCR trial modified the recovery to be eccentric cycling (5 min, 60% PPO). High intensity workload (CONR: 187 +/- 17; ECCR: 187 +/- 21 W), oxygen consumption (CONR: 2.55 +/- 0.17; ECCR: 2.68 +/- 0.20 L . min(-1)), heart rate (CONR: 165 +/- 7; ECCR: 171 +/- 10 beats . min(-1)) and RPE legs (CONR: 15 +/- 3; ECCR: 15 +/- 3) were equivalent between trials. Eccentric cycling recovery significantly increased external workload (CONR: 93 +/- 18; ECCR: 196 +/- 24 W, P < 0.01) yet lowered oxygen consumption (CONR: 1.51 +/- 0.18; ECCR: 1.20 +/- 0.20 L . min(-1), P < 0.05) while heart rate (CONR: 132 +/- 13; ECCR: 137 +/- 12 beats . min(-1)) and RPE of the legs (CONR: 11 +/- 7; ECCR: 12 +/- 7) remained equivalent. There was no significant difference in the aural temperature between the trials (ECCR: 37.3 +/- 0.1 degrees C; CONR: 37.4 +/- 0.1 degrees C, P > 0.05), yet during recovery periods mean skin temperature was significantly elevated in the ECCR (ECCR: 33.9 +/- 0.2 degrees C; CONR: 33.3 +/- 0.2 degrees C, P < 0.05). Participants preferred ECCR (10/12) and rated the ECCR as more achievable (82.8 +/- 11.4 mm) than CONR (79.4 +/- 15.9 mm, P < 0.01). In conclusion, eccentric cycling during the recovery period of a HIIT training session, offers a novel approach to concurrent training methodology. The unique cardiopulmonary and skeletal muscle responses facilitate the achievement of both training stimuli within a single exercise bout.