Acute effects of different blood flow restriction conditioning protocols on countermovement and squat jump performance.

Background: This study examined the acute effects of different blood flow restriction (BFR) conditioning protocols on countermovement jump (CMJ) and squat jump (SJ) performance. Methods: Eighteen physically active males completed five experimental conditions: an unconditioned control condition (CON) and four active BFR conditioning protocols comprising 30% or 85% 1RM with 1- or 4-min recovery. CON was performed first, after which the four active conditions were randomized without replacement. CMJ and SJ order was independently randomized within each condition. Results: After false discovery rate adjustment across the biomechanical outcomes, no statistically significant condition effects remained. Likewise, no significant load, recovery-interval, or load × recovery effects were identified within the four active BFR protocols, and no jump type × condition interaction remained significant after multiplicity adjustment. Exploratory protocol-versus-CON contrasts showed differences in selected force-time variables, but these findings should be interpreted cautiously because the active protocols were preceded by a standardized warm-up whereas CON was not. Conclusion: The tested BFR conditioning protocols did not provide robust evidence of acute enhancement of explosive jump performance. The findings should be interpreted as responses to the specific conditioning protocols tested rather than as evidence of an isolated BFR effect.