Proceedings of The Physiological Society
University of Manchester (2010) Proc Physiol Soc 19, PC65
Training changes in elderly tendon is gender-specific for both magnitude and characteristics
G. L. Onambele1, S. J. Pearson2
1. Sport & Exercise Science, Manchester Metropolitan University, Alsager, United Kingdom. 2. Health sport & rehabilitation sciences, University of Salford, Manchester, United Kingdom.
Mechanical properties of tendons are modified with resistance exercise (1), including in the elderly (2). Moreover, Ochala et al. (3) suggested that gender differences existed in musculoarticular stiffness with training in the elderly, which is suggestive of differential tendon training responses, as there appears to be no gender difference in the mechanical properties of the tendon in this age group (4). The aim of the current study was thus to examine whether tendon stiffness differentially alters with training in elderly males compared with females. Fourteen healthy, habitually active elderly persons (7 males aged 74 ± 3 years (Mean ± SD) and 7 females aged 77 ± 3 years) were tested at baseline and after 12 weeks of resistance training. The local Ethics committee approved this study and subjects gave written informed consent. With training, relative quadriceps maximum voluntary isometric force increased to a similar degree in males (2470 ± 445N to 3097 ± 693N (p<0.01)) and in females (1729 ± 361N to 2167 ± 359N (p<0.05)). Patella tendon stiffness showed a mean increase, across all relative force levels (10-100% MVC - see figure 1), which was greater in the males (338 ± 84 N/mm to 617 ± 186 N/mm (p<0.001)) compared to that in the females (339 ± 98 N/mm to 373 ± 81 N/mm (p<0.001)). Interestingly, a ‘cut-off point’ (~40%MVC) was identified, relating to a gender-specific pattern in the changes in tendon stiffness. Below this force level, females exhibited their highest tendon stiffness increases whereas above this point tendon adaptations were minimal. The males exhibited their highest tendon stiffness increases above this point. To confirm that the above gender responses were independent of the forces at which stiffness was estimated, we also measured this characteristic at a standardised force level (1200 N). Here the changes were 6 ± 1% vs. 82 ± 3% increments in the females and the males respectively (p<0.001). [Figure 1] We show here that older females’ tendon is modulated less than males’ in agreement with previous work on tendon dimensions (5). We also show that the forces at which the greatest adaptations are exhibited differ by gender. It may be that the female tendon preferentially requires low forces to respond to training whereas the male tendon seems to adapt to all force levels, though preferentially to relatively high forces (≥40% MVC). We thus propose that both training and rehabilitation regimens should consider gender-specific tendon responsiveness.
Where applicable, experiments conform with Society ethical requirements