The influence of handcycling warmup protocol intensity on workload production during sprint tests in athletes with spinal cord injuries.

OBJECTIVES

Post activation potentiation (PAP) is the phenomenon where muscle force-generating capacity during explosive activities increases after sustained activation. Alternatively, fatigue refers to the decrease in muscle force-generating capacity following sustained activation. The level to which muscles are fatigued or potentiated may influence whether performance is enhanced or decreased. While PAP has been well-documented in able-bodied athletes, few studies have examined PAP in athletes with spinal cord injuries (SCI). Therefore the objective of this study was to examine the influence of warmup protocol intensity on workload production during a 15-second handcycling sprinting task in athletes with SCI.

DESIGN

Within-subject design with repeated measures, n = 19 wheelchair users.

METHODS

We examined the power output, work, and kinetics during a maximal effort task (handcycling sprinting) before and after high and moderate intensity exercise to determine the acute effects of different warmup intensities on work production during sprinting.

RESULTS

Potentiation (defined as a >7.5% increase in total work completed during sprinting compared to baseline) was observed after both moderate (p = 0.0001) and high intensity exercises (p = 0.001), with more participants potentiated following moderate (n = 11) compared to high intensity (n = 10). Increases in work completed during the sprints can be traced back to increases in tangential force applied at the handle at the beginning of the sprint test.

CONCLUSIONS

Most participants were not fatigued following either exercise protocol, which is encouraging for recommending both protocols for people with SCI. Additionally, warmups for handcycling, especially handcycling sprinting, should be moderate intensity to potentiate the muscles rather than interval cycling or "ramp-up" activities.