Spring-Mass Behavior during Exhaustive Run at Constant Velocity in Elite Triathletes.

The article presents a study which examines the behavior of leg-spring during an exhaustive run with constant velocity in elite triathletes. The study also aims to examine if the modifications were related to an increment in the energy cost of running through evaluating nine elite triathletes who ran to exhaustion in an indoor track. The cost of running was measured using a breath-by-breath portable gas analyzer and vertical and horizontal ground reaction forces were measured every lap. The results of the study show that changes in leg and vertical stiffness were related with modifications of aerial time and that fatigue induces stiffness which decreases maximal vertical force.