Leg Tuck or Plank? Critical Decisions to Optimize Physical Fitness Assessment in Army Personnel

Sergi, TE, Dawes, JJ, and Heileson, JL. Leg tuck or plank? Critical decisions to optimize physical fitness assessment in army personnel. J Strength Cond Res 39(6): e830-e833, 2025-Recent updates to the Army Combat Fitness Test (ACFT), primarily surrounding the decision to replace the leg tuck (LTK) with the plank (PLK), have raised significant controversy. The original justification for the LTK included combat tasks associated with upper-body pulling and abdominal strength, which may not be measured by the PLK. Sixty (30 male and 30 female) healthy, active-duty soldiers volunteered for this study and conducted performance testing for handgrip strength (HGS), PLK, LTK, and pull-ups (PUPs). Independent t-tests were used to determine between-sex differences for all variables (p ≤ 0.05). Partial correlations controlling for sex were used to compute relationships between the LTK, PLK, HGS, and PUP. Stepwise regression determined which variables were predictive of the LTK and PLK. Men outperformed female soldiers in HGS, LTK, and PUP, whereas PLK performance was similar. When controlling for sex, the LTK was correlated with PUP (r = 0.784, p < 0.001), HGS (r = 0.353, p = 0.006), and the PLK (r = 0.321, p = 0.013). The LTK was predicted by PUP and sex (model 2: R2 = 0.790). The inclusion of sex to the model, albeit significant, only improved the variance by 3.8%. The PLK was predicted by the LTK (R2 = 0.135, p = 0.004). The results suggest that the LTK is a complex exercise that reflects multiple fitness components that are no longer assessed by the PLK. The Army has reinstituted sex-stratified scoring, as such, ACFT event selection should align with the most operationally relevant components of fitness.