Timing of Preexercise Partial-Body Cryotherapy Exposure to Promote Jump Performance.

Purpose: This study evaluated the effect of partial-body cryotherapy (PBC) exposure 1, 2, or 3 hours before maximal-effort jump performance, salivary enzyme concentration, perceived readiness, and well-being. Methods: Male team-sport players (N = 27; 24.2 [3.6] y; 91.5 [13.2] kg) were exposed to a blinded bout of PBC (−135°C [6°C]) and control (−59°C [17°C]) either 1, 2, or 3 hours prior to countermovement jumps. Passive saliva samples were collected to determine α-amylase concentration. Self-reported performance readiness and well-being questionnaires were completed using a 1–5 Likert scale. Results: Differences in the change in mean countermovement jump velocity and absolute power between PBC and control were unclear at 1 hour (+1.9% [5.3%], P =.149; +0.7% [10.6%], P =.919; mean difference [90% confidence limits]), 2 hours (+3.3% [2.7%], P =.196; +7.8% [7.4%], P =.169), and 3 hours postexposure (+3.1% [3.3%], P =.467; +0.7% [4.8%], P =.327). Salivary α-amylase concentration was elevated 15 minutes postexposure in the 1-hour (+61% [14%], P =.008) and 2-hour groups (+55% [12%], P =.013). The increase in self-reported performance readiness was higher after PBC (+2.4 [1.2] units, P =.046) in the 2-hour group and by 1.4 (1.1) units (P =.023) after 3 hours. Mental fatigue was favorably decreased 2 hours after PBC exposure (+0.5 [0.1], P =.041). Conclusions: An acute exposure of PBC elicits potentially favorable but unclear changes in countermovement jump performance. The PBC enhances salivary α-amylase concentration and perceived performance readiness, reduces mental fatigue, and could be useful in sport-specific training or competitions. [ABSTRACT FROM AUTHOR]