Effects of Combined Uphill–Downhill Sprinting Versus Resisted Sprinting Methods on Sprint Performance: A Systematic Review and Meta-analysis

Response to Comment on “Effects of Combined Uphill–Downhill Sprinting Versus Resisted Sprinting Methods on Sprint Performance: A Systematic Review and Meta-analysis’’

“…Future research should directly control and compare RS against UDS to elucidate possible differences in performance adaptations." [2]. Despite these caveats, it seems Xu et al misinterpreted our position.…”

“…While the precise mechanisms are yet to be fully elucidated, prior authors suggested that the immediate transition from the overloaded (uphill) to overspeed (downhill) condition might result in enhanced neuromuscular outputs [3,4]. It also must be emphasized that we were the first to advocate for caution and nuance with respect to our results [2] (see as well Limitations section), "Despite this, it is important to be weary of differences in outcomes within this review considering the outlined methodological differences. Future research should directly control and compare RS against UDS to elucidate possible differences in performance adaptations."…”

“…Our point here is that Xu et al [1] claimed we made statements about RS and assisted sprinting's superiority in acceleration and maximum velocity phases, respectively, when, in fact, we simply noted that each of these phases have different exposures and demands [2]. This sequence of logic led us to hypothesize that a sprint intervention which addresses both ends may be advantageous and could "perhaps" be the reason uphill-downhill sprinting (UDS) showed more favorable results.…”

“…[8] study, for differences between RS and traditional sprinting, the within-group effect sizes are 0.91 and 0.92, respectively, and the between-group SMD for 0-5 m should be 0. They further claim that the point in our metaregression is − 0.15, when it is in fact − 0.16 as presented in Table 3 from the original paper [2]. Owing to the lack of disclosure in how Xu et al calculated a SMD of 0, we went back to the McMorrow et al paper [8] and calculated the effect size again.…”

“…While resisted sprint methods may serve as a teaching tool to help with technique and posture, in the context of this paper, resisted sprinting performance enhancements do not seem superior to those of traditional sprinting, but more investigations are warranted." [2].…”