Luke J. Stevens

Stevens, LJ, Carey, DL, Gastin, PB, and James, LP. Validity and reliability of a 3-point load-velocity profile for predicting hex bar deadlift 1 repetition maximum. J Strength Cond Res XX(X): 000–000, 2026—This study assessed the between-session reliability of load-velocity–derived parameters in the hex bar deadlift using a 3-point method and velocity-based load prescription and determined the validity of a predictive 1RM model based on these parameters relative to actual 1RM testing. Nineteen resistance-trained subjects completed 2 testing sessions consisting of a traditional 1RM test and a submaximal 3-load load-velocity assessment using the hex bar deadlift. Between-session reliability of measures derived from the load-velocity profile and 1RM testing were evaluated using coefficient of variation (CV) and intraclass correlation coefficient (ICC). A linear mixed-effects model was used to predict 1RM from theoretical maximal load (L ₀ ) and theoretical maximum velocity (V ₀ ) derived from individual load-velocity profiles. Bland-Altman plots with 95% limits of agreement were used to assess the level of agreement between methods. Between sessions, L ₀ showed excellent reliability (CV = 5.2%, ICC = 0.97), while V ₀ was generally less reliable (CV = 6.0%, ICC = 0.70). The predictive model explained nearly all variance in actual 1RM (marginal R ² = 0.975), with both L ₀ and V ₀ contributing significantly ( p < 0.05). Predicted 1RM values were highly similar to actual 1RM values on average; however, the limits of agreement (±15.7 kg) suggest that the 2 methods are not directly interchangeable. Overall, the methodology used in this study provides a feasible alternative for assessing maximal strength, offering a less fatiguing and efficient option for athlete monitoring. However, due to individual variability, predicted 1RM values should not be used interchangeably with direct 1RM testing.

Purpose : The aim of this study was to examine the effects of procedure, ranking method, and summarization method on between-sessions reliability and magnitude of force measures for the isometric midthigh pull. Methods : Thirty-two national- and international-level athletes performed short (∼1 s) and traditional (3–5 s) isometric midthigh pull protocols during consecutive weeks. Net force at peak (PF) and net force at 50, 100 (NF100), 150, and 200 milliseconds were collected. Trials were ranked using PF and NF100, and 4 summarization methods were applied: mean, mean of best 3, mean of best 2, and best trial. Reliability statistics were calculated for the resulting data combinations, and linear mixed models were used to assess differences between the most reliable conditions for each procedure. Results : For early force measures (≤200 milliseconds), the short procedure demonstrated superior reliability compared with traditional, specifically when trials were ranked on NF100 (traditional [mean]: intraclass correlation coefficient [ICC] = .68–.82, coefficient of variation [CV] = 12.0%–16.0%; short [mean best 3, ranked on NF100]: ICC = .77–.91, CV = 8.2%–10.8%). For PF, all conditions exhibited good to excellent reliability (ICC = .89–.97, CV = 4.7%–7.4%), but it was slightly better with traditional procedures. All early force measures were significantly greater ( P < .001) using the short procedure, with mean differences of 15% to 28%. Conversely, PF was significantly lower ( P < .001) using the short procedure (−9% on average), although individual differences varied. Conclusions : Ideally, both traditional and short procedures would be implemented to comprehensively assess peak and early force-generating capacity. However, the short procedure offers a time-effective and reliable alternative to assess both capacities more efficiently.

Purpose: Rugby union is a contact team sport demanding high levels of physical capacity, and understanding the match workloads can be useful to inform training. In this study, the factors influencing locomotion and contact workloads for offensive and defensive ball-in-play periods are quantified. Methods: Locomotion and contact metrics were collected from global positioning system units and videos for 31 professional players of a Super Rugby team across 14 games in the 2021 season. Data were analyzed with a generalized mixed-model procedure that included effects for type of play, playing position, match outcome, and ball-in-play time. Magnitudes were assessed with standardization, and evidence for substantial magnitudes was derived from sampling uncertainty. Results: When offense was compared to defense, most metrics showed decisively substantial increases (small to moderate) for forwards and backs. There was decisive evidence that locomotion metrics were substantially lower (large differences) and contact metrics were higher (very large differences) when comparing forwards to backs on offense and defense. When winning was compared to losing, there was good evidence that forwards experienced small increases in overall workload on defense, and backs experienced a small increase in high-speed running and a moderate decrease in contacts on offense. Match-to-match changes associated with ball-in-play time, attributed to fatigue, were decisive (moderate to very large) across most metrics for forwards and backs in offense and defense. Conclusions: The increased locomotion and contact workloads in offensive periods and the differing physical requirements between positions and match outcomes for both types of play are novel findings that should aid practitioners in designing effective training.