Acute and Delayed Effects of Time-Matched Very Short All Out Efforts in Concentric vs. Eccentric Cycling

Background: To the authors' knowledge, there have been no studies comparing the acute responses to all out efforts in concentric (isoinertial) vs. eccentric (isovelocity) cycling. Methods: After two familiarization sessions, 12 physically active men underwent the experimental protocols consisting of a 2-min warm-up and 8 maximal efforts of 5 s, separated by 55 s of active recovery at 80 rpm, in concentric vs. eccentric cycling. Comparisons between protocols were conducted during, immediately after, and 24-h post-sessions. Results: Mechanical (Work: 82,824 +/- 6350 vs. 60,602 +/- 8904 J) and cardiometabolic responses (mean HR: 68.8 +/- 6.6 vs. 51.3 +/- 5.7% HRmax, lactate: 4.9 +/- 2.1 vs. 1.8 +/- 0.6 mmol/L) were larger in concentric cycling (p < 0.001). The perceptual responses to both protocols were similarly low. Immediately after concentric cycling, vertical jump was potentiated (p = 0.028). Muscle soreness (VAS; p = 0.016) and thigh circumference (p = 0.045) were slightly increased only 24-h after eccentric cycling. Serum concentrations of CK, BAG3, and MMP-13 did not change significantly post-exercise. Conclusions: These results suggest the appropriateness of the eccentric cycling protocol used as a time-efficient (i.e., similar to 60 kJ in 10 min) and safe (i.e., without exercise-induced muscle damage) alternative to be used with different populations in future longitudinal interventions.

Automated summary

This study compared acute responses to all out efforts in concentric vs. eccentric cycling, revealing that concentric cycling induced larger mechanical and cardiometabolic responses. Perceptual responses to both protocols were similar, with an immediate potentiation of vertical jump after concentric cycling and slight increases in muscle soreness and thigh circumference only 24 hours after eccentric cycling.