Structural and Functional Properties of Lower Extremity Tendons in Men

Area of Science:

• Sports Medicine
• Exercise Physiology
• Biomechanical Engineering

Background:

• Understanding tendon adaptations to resistance training is crucial for optimizing performance and injury prevention.
• Previous research indicates varied responses in connective tissues to mechanical loading.
• The role of systemic biomarkers in mediating tendon changes remains unclear.

Purpose of the Study:

• To compare structural and functional tendon properties between resistance-trained (RT) and recreationally active (NR) young men.
• To assess differences in body composition (lean body mass and bone mineral density) between groups.
• To investigate the relationship between serum collagen turnover markers and tendon/bone adaptations.

Main Methods:

• Ultrasonography and dynamometry were used to measure patellar and Achilles tendon properties at rest and during maximal voluntary isometric contractions.
• Dual-energy X-ray absorptiometry assessed lean body mass and bone mineral density.
• Serum samples were analyzed for collagen turnover markers.

Main Results:

• Resistance-trained men exhibited significantly greater lean body mass and bone mineral density compared to the control group.
• Patellar tendon stiffness and Young's modulus were significantly higher in RT men, but cross-sectional area did not differ.
• Achilles tendon cross-sectional area was larger in RT men, yet stiffness and modulus showed no significant differences between groups.

Conclusions:

• Heavy resistance training enhances lean body mass and bone mineral density in young men.
• Tendon adaptations to resistance training are differential, affecting the patellar and Achilles tendons differently.
• Serum collagen turnover markers did not correlate with tendon or bone adaptations, suggesting limited involvement in these specific changes.