My coach says: The effects of accelerated eccentric and landing cues to elicit change in countermovement jump propulsive and landing performance

The aim of the study was to determine if an accelerated eccentric (AE) cue during a countermovement jump (CMJ) produces distinct kinetic outputs. Eighteen strength-trained men (mean ± SD: Age = 25.9 ± 4.5 years; body mass = 87.1 ± 12.2 kg; stature = 181.7 ± 6.2 cm) completed a jump cue ("jump as high and fast as possible") (NORM) or AE ("fast downward, max braking, and jump as high and fast as possible") with 2 types of landing cues: Deceleration eccentric (DC) ("decelerate as fast as possible once landed") and dissipating eccentric (DP) ("stop in your own time"). The Hawkin Dynamics Cloud system was used for jump analysis, including additional landing metrics. Subjects performed 4 repetitions of AEDC landling, AEDP landling, NORMDC landling, and NORMDP landling in a randomized order on 2 separate occasions. When compared with the NORM conditions, the AE conditions had significantly greater peak and mean braking velocity (effect size [ES] = -0.77 to -0.89 and -0.60 to -0.83, respectively), mean braking power (ES = -0.56 to -0.59), mean braking force (ES = 0.40-0.46), braking impulse (ES = 0.35-0.41), force at minimal displacement (ES = 0.26-0.32), and peak propulsion force (ES = 0.24-0.26), with a reduced braking phase time (ES = 0.59-1.14). Only landing impulse showed acceptable reliability for landing metrics, with no significant differences between groups. Findings highlight AE's enhance braking (eccentric) metrics and overall CMJ performance. Future research should explore AE in strength-based exercises and further investigate CMJ landing phase metrics.