High-intensity resistance training and collagen supplementation improve patellar tendon adaptations in professional female soccer athletes

Lee J, Robshaw DC, Erskine RM · Experimental Physiology

Replicates the mechanical finding in a different population and separates it from size. Patellar tendon stiffness rose 15.4 plus or minus 3.1% (d=0.81) against 4.6 plus or minus 3.0% on placebo (p=0.002), and Young's modulus 14.2 plus or minus 4.0% (d=0.65) against 3.4 plus or minus 2.8% (d=0.15, p=0.004). Cross-sectional area showed a training effect but no group interaction (p=0.934) — so the tendon became stiffer without becoming larger. No conflicts declared.

Population

Professional female soccer athletes aged 25.7 plus or minus 4.2, three high-intensity sessions weekly

Intervention

30 g hydrolysed collagen with 500 mg vitamin C before each session, 10 weeks (n=6)

Comparator

Energy-matched placebo (n=5), same training

Limitations

Six and five per arm — the smallest trial in this group, and effect sizes from eleven people carry very wide uncertainty whatever the p-values. Professional athletes in season, so training load is neither standardised nor isolated. Healthy tendon; no functional or injury endpoint. Tendon, not cartilage.