Sports Med. 2026 Feb 23. doi: 10.1007/s40279-026-02395-7. Online ahead of print.
ABSTRACT
BACKGROUND: The literature is equivocal on whether complex training (i.e., combining traditional resistance and ballistic exercises within a single session) is superior to ballistic training in improving physical fitness qualities. This systematic review with meta-analysis aims to compare the effects of complex and ballistic training on physical fitness outcomes.
METHODS: A systematic search using the PRISMA 2020 guidelines was conducted in electronic databases (i.e., PubMed, Scopus, Web of Science). From the included studies, data were extracted for linear sprint, vertical jump (i.e., countermovement jump, squat jump), change of direction speed, and maximal strength. The risk of bias of the included studies was assessed using RoB-2 and ROBINS-I tools for randomized and nonrandomized studies, respectively. The meta-analyses were computed using a DerSimonian and Laird random effects model, reporting Hedges’ g effect size (ES) with 95% confidence and prediction intervals. Statistical significance was set at p ≤ 0.05. In addition, the certainty of evidence was assessed using the GRADE approach.
RESULTS: A total of 20 studies were initially eligible. However, one study was excluded owing to critical concerns at risk of bias assessment stage. Thereafter, 19 studies involving 537 participants ranging from “tier 0” (i.e., sedentary) to “tier 3” (i.e., highly trained) level were included. Randomized studies presented low (k = 2), some (k = 10), and high concerns (k = 5) regarding the risk of bias, while nonrandomized studies presented moderate concerns (k = 2). Compared with ballistic training, significantly greater improvements were reported after complex training for one-repetition maximum (ES = 1.12, p = 0.010), squat jump (ES = 0.37, p = 0.004), 10 m (ES = 0.67, p = 0.033), and 40 m (ES = 0.72, p = 0.005) linear sprint. Furthermore, a significant moderating effect of training duration was observed for complex training, favoring longer (> 7.5 weeks) interventions. The certainty of the evidence was low for the squat jump and very low for all other outcomes.
CONCLUSIONS: Our findings suggest complex training to be superior in improving one-repetition maximum squat, squat jump, 10 m, and 40 m linear sprint compared with ballistic training alone. However, 5 m, 20 m, change of direction speed, countermovement jump, and jump power were similarly improved after both training methods. In addition, a longer intervention duration (> 7.5 weeks) may optimize complex training effects. However, the certainty of the evidence was low for the squat jump and very low for all other outcomes. To increase confidence in the certainty of the current evidence, and therefore to provide robust recommendations favoring (or not) the use of complex training (and its prescription factors) over ballistic training to improve participants’ physical fitness, more robust studies would be required (e.g., larger samples).
PROTOCOL REGISTRATION: The protocol was published in the Open Science Framework (OSF) platform on 13/04/2024 (DOI: https://doi.org/10.17605/OSF.IO/STUZ7 ; Archive link: https://archive.org/details/osf-registrations-stuz7-v1 ).
PMID:41731268 | DOI:10.1007/s40279-026-02395-7
