Early-season changes in concentric-only, long and short stretch-shortening cycle jump performance in highly trained...

In basketball, most studies analysing seasonal variations in neuromuscular performance through vertical jump testing rely solely on the countermovement jump (CMJ), a slow stretch-shortening cycle (SSC) test. This study aimed to analyse early-season changes in jumping performance in highly-trained youth basketball athletes, utilizing a comprehensive jump test battery to determine the time-course of adaptations in concentric-only qualities (using the squat jump, SJ), and slow (through the CMJ) and fast SCC function (via the drop jump and repeated jump tests, DJ and RJ).

Twenty-six players (under-16: n = 14; age:14.9 ± 0.3 years; under-18: n = 12; age: 16.7 ± 0.4 years) from a high-level basketball academy volunteered to participate. In the first (T1) and final week (T2) of the pre-season, and four weeks into the in-season (i.e. week nine of the training period, T3), players completed the following tests on a contact mat on the same day: SJ, CMJ, DJ and RJ. To examine the progression of each vertical jump test across the selected different phases of the season, a repeated measures ANOVA with time (T1, T2 and T3) as factor was conducted.

SJ and CMJ height improved only from T1 to T2 (both p < 0.001). DJ height remained constant, but shorter ground contact times (GCT) were observed in T2 and T3 when compared to T1 (p = 0.018 and p < 0.001, respectively). Moreover, significant and gradual increases were found in DJ reactive strength index (RSI) (T1 to T2: p = 0.039; T2 to T3: p < 0.030). In the RJ, significant improvements were found only for RSI between T2 and T3 (p = 0.005).

Reactive strength qualities and fast SSC performance peaked during the early in-season, while changes in concentric-only and slow SSC function (assessed with SJ and CMJ, respectively) occurred exclusively during the pre-season.KEY MESSAGESDifferent vertical jump tests showed distinct early-season changes in youth basketball.Squat (SJ) and Countermovement Jump (CMJ) performance improved only during the pre-season, while reactive strength qualities assessed via the Drop Jump (DJ) and Repeated Jumps peaked during the early in-season.DJ reactive strength index and ground contact times might be more sensitive than CMJ or SJ height to detect changes in neuromuscular capabilities in-season.