In vivo human tendon mechanical properties: effect of resistance training in old age.

Recent advances in ultrasound scanning have made it possible to obtain the mechanical properties of human tendons in vivo. Application of the in vivo method in elderly individuals showed that their patellar tendons stiffened in response to a 14-week resistance training program by approximately 65% both structurally and materially. The rate of muscle torque development increased by approximately 27%, indicating faster contractile force transmission to the skeleton. The present findings suggest that strength training in old age can, at least partly, reverse the deteriorating effect of ageing on tendon properties and function.