Optimizing Resistance Training Outcomes: Comparing In-Person Supervision, Online Coaching, and Self-Guided Approaches: A Randomized Controlled Trial.

Gavanda, S, Held, S, Schrey, S, Oberwetter, K, Lazzaro, P-GM, Pergelt, M, and Geisler, S. Optimizing resistance training outcomes: comparing in-person supervision, online coaching, and self-guided approaches: a randomized controlled trial. J Strength Cond Res XX(X): 000-000, 2025-This randomized, parallel-group trial investigated the effects of supervised (SUP), app-guided (APP), and self-guided (PDF) 10-week, thrice-weekly full-body resistance training (RT) on strength, body composition, well-being, and supervision satisfaction (S-SRQ) in trained men and women (n = 79, 48% women; 30.7 ± 7.8 years, 1.75 ± 0.1 m, 77.5 ± 17.5 kg). Adherence was highest in SUP (88.2%), followed by APP (81.2%) and PDF (52.2%). At p ≤ 0.05, body mass (+1.8 ± 1.9 kg, p = 0.006) and fat-free mass (+1.4 ± 0.9 kg, p ≤ 0.001) increased significantly in SUP. Muscle mass gains were observed in SUP (+1.4 ± 0.9 kg, p = 0.009) and PDF (+0.9 ± 1.3 kg, p = 0.047). All groups improved squat 1-repetition maximum (1RM) (SUP: +26.6 ± 6.5 kg, p ≤ 0.001; APP: +19.2 ± 11.0 kg, p ≤ 0.001; PDF: +19.4 ± 11.7 kg, p ≤ 0.001) and bench press 1RM (SUP: +9.1 ± 3.5 kg, p ≤ 0.001; APP: +8.2 ± 4.0 kg, p ≤ 0.001; PDF: +7.7 ± 5.8 kg, p ≤ 0.001). Supervised showed significantly greater squat gains than APP and PDF (p ≤ 0.044). Well-being (WHO-5) improved in SUP (+15.7 ± 16.2 points, p ≤ 0.001) and PDF (+9.0 ± 20.4 points, p = 0.032). Satisfaction with supervision was significantly higher in SUP (96.7 ± 4.3%) than in APP (92.0 ± 7.1%, p = 0.005). In conclusion, supervised RT resulted in superior improvements in strength, body composition, well-being, and supervision satisfaction compared with app-guided or self-guided training. Although APP and PDF resulted in some positive effects, their magnitude was generally smaller. These findings underscore the value of in-person coaching in optimizing RT outcomes. However, app-based RT shows promise for maintaining adherence, offering a viable alternative when full supervision is not feasible.