Returners exhibit greater jumping performance improvements during a peaking phase compared to new players on a volleyball team

Purpose: To determine if jumping performance changes during a peaking phase differed between returners and new players in a female collegiate volleyball team and to determine which variables best explained the variation in performance changes. Methods: Fourteen volleyball players were divided into two groups: returners (n=7) and new players (n=7) who completed a 5-week peaking phase prior to conference championships. Players were tested at baseline prior to the pre-season on measures of vastus lateralis cross-sectional area using ultrasonography, estimated back squat one repetition maximum (1-RM), and countermovement jump height (JH) and relative peak power (PPa) on a force platform. Jumping performance, rating of perceived exertion training load, and sets played were recorded weekly during the peaking phase. Results: There were moderate to very large (p<0.01, Glass’s Δ=1.74), and trivial to very large (p=0.07, Δ=1.09) differences in JH and PPa changes in favor of returners over new players during the peaking phase, respectively. Irrespective of group, 7 of 14 players achieved peak JH two weeks after the initial overreach. The number of sets played (r=0.78, p<0.01) and athlete’s pre-season relative 1-RM (r=0.54, p=0.05) were the strongest correlates of JH changes during the peaking phase. Conclusions: Returners achieved greater improvements in jumping performance during the peaking phase compared to new players, which may be explained by the returners’ greater relative maximal strength, time spent competing, and training experience. Thus, volleyball and strength coaches should consider these factors when prescribing training during a peaking phase to ensure their players are prepared for important competitions