What question did this study set out to answer?

This research aims to evaluate the effectiveness of high-intensity resistance training combined with nutritional support on muscle strength compared to standard rehabilitation following knee surgery.

April 22, 2026

High-Intensity Resistance Training Enhances Strength, But Not Muscle Mass and Physical Functioning Gains During Total Knee Arthroplasty Rehabilitation

Key Points

This research aims to evaluate the effectiveness of high-intensity resistance training combined with nutritional support on muscle strength compared to standard rehabilitation following knee surgery.
Randomized trial with 33 patients post-total knee arthroplasty assigned to high-intensity resistance exercise plus rehabilitation or standard rehabilitation only.
The intervention involved three weekly sessions of bilateral resistance training and daily nutritional supplementation over 12 weeks.
Outcomes measured included strength in leg press exercises, muscle mass using DXA scans, and functional tests.
Bilateral leg press strength significantly improved in the resistance training group compared to the standard group.
Strength gains in the non-operated leg were notable in the resistance training group only.
No significant difference in muscle mass increase was observed between the two groups, indicating strength improvements without corresponding muscle mass gain.

Abstract

Purpose: To determine whether high-intensity resistance exercise training with nutritional support (RET) during recovery from total knee arthroplasty (TKA) induces greater improvements in muscle-related outcomes compared to standard rehabilitation alone (SR). Methods: Thirty-three patients (70±6 y; 28.7±3.1 kg·m -2 ) were randomized to receive RET (intervention+regular rehabilitation, n=18) or SR (regular rehabilitation only, n=15) for 12 weeks, starting 8 weeks post-TKA. RET involved supervised, bilateral, high-intensity resistance exercise, 3x/week, daily supplementation (45g protein, 5.5 g Vivinal® GOS, 800 IU vitamin D, 366 mg calcium), and dietary counselling. Outcomes included bilateral and unilateral leg press 1RM, DXA-derived appendicular lean mass (ALM), CT-derived quadriceps cross-sectional area (CSA), 6-min walking test (6MWT) and 5-times chair-stand test (5CST). Data are mean±SD, analysed with 2-way repeated-measures ANOVAs, or median IQR, analysed with Wilcoxon Signed-Rank test. Results: Bilateral leg press 1RM improved to a greater extent following RET (131±38 to 174±56 kg, P <0.001) vs SR (124±36 to 143±49 kg, P =0.018, P - interaction =0.026). Strength in the non-operated leg increased in the RET group only (RET: 22±17%, P <0.001, SR: 6±11%, P =0.175, P-interaction =0.002). Operated leg strength increased similarly between groups (RET: 51±33%, SR: 40±30%, P-time <0.001, P-interaction =0.338), as did ALM (RET: 0.5±0.8 kg, SR: 0.3±0.8 kg, P - time =0.009, P - interaction =0.390), and quadriceps CSA (operated: RET: 7.8±7.5%, SR: 9.2±5.9%, non-operated: RET: 4.8±4.5%, SR: 3.8±3.7%, P - time <0.001, P-interaction ≥0.557). 6MWT improved more in the SR (428±94 to 513±75 m, P <0.001) vs RET group (417±69 to 460±72 m, P =0.002, P - interaction =0.034). 5CST only improved significantly following RET (RET: 15.3 4.2 to 13.2 3.9 s, P =0.039, SR: 14.4 4.0 to 14.4 5.1 s, P =0.064). Conclusions: Compared to standard TKA rehabilitation, high-intensity resistance training with nutritional support induces greater gains in bilateral strength but not muscle mass or physical functioning.

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High-Intensity Resistance Training Enhances Strength, But Not Muscle Mass and Physical Functioning Gains During Total Knee Arthroplasty Rehabilitation

Key Points

Abstract

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