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

Abstract

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 × 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°C; CONR: 37.4 ± 0.1°C, P > 0.05), yet during recovery periods mean skin temperature was significantly elevated in the ECCR (ECCR: 33.9 ± 0.2°C; CONR: 33.3 ± 0.2°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.