Isometric Strength Adaptations After Two Consecutive 12-week Strength and Conditioning Programs in U.S. Air Force...

Brojanac, AP, Haynes, H, Mota, J, Puleali'i, S, Schwarz, AV, Johnson, MF, Kaylor, MG, Addison, A, Young, T, Klubertanz, M, Patton, M, and Graybeal, AJ. Isometric strength adaptations after two consecutive 12-week strength and conditioning programs in U.S. Air Force ROTC cadets: The STAR Program. J Strength Cond Res XX(X): 000-000, 2026-This study evaluated changes in upper and lower body isometric force production during two 12-week implementations of formal strength and conditioning programs in 2 cohorts of male and female Air Force Reserve Officer Training Corps cadets. Forty-two cadets in the fall and 39 cadets in the spring semesters completed 2 uniquely structured strength and conditioning interventions as part of the Supporting Tactical Athlete Readiness Program. Isometric mid-thigh pull tests were used to assess lower body force production in the fall, and athletic shoulder tests were used to assess upper body force production in the spring. Air Force Reserve Officer Training Corps physical fitness assessments and body composition using dual-energy X-ray absorptiometry were assessed across both semesters. Significance was set at p ≤ 0.050. Absolute and relative peak force (PF), PF at 300 milliseconds, and leg muscle quality index increased, while rate of force development decreased, after the fall program (p ≤ 0.035). These changes were no longer significant after adjusting for baseline lean soft tissue, which revealed positive associations with change in earlier PF production (p ≤ 0.039). After the spring semester, shoulder girdle muscle quality index, absolute and relative average force (AF), and PF increased, while bilateral PF asymmetry decreased (p ≤ 0.039). These improvements were no longer significant after adjusting for baseline lean soft tissue, which was positively associated with ΔAF and ΔPF (p ≤ 0.033). Improvements in strength can be achieved through structured training programs, though success may be determined by muscular preconditioning. Incorporating field-friendly assessments such as isometric mid-thigh pull and athletic shoulder testing may further support cadet monitoring, reduce injury risk, and support long-term tactical performance.