Tendons are collagenous structures that attach muscle to bone and function as springs or rubber bands to save energy during locomotion. Previous studies show that tendons regain about 95% of the energy when they recoil from high physiological strains, but tendon elastic modulus is lower at low strains in the toe region where crimped molecules straighten with little resistance. Thus, the energy losses exhibited by tendons in this region may be higher, and the recovery of energy may be lower at lower strains such as slow walking and jumping. We stretched the Achilles tendon of mice in vitro at various frequencies (1.0-9.0 Hz) and amplitudes (0.25mm-1.75mm), and quantified tendon hysteresis. Contrary to our predictions and prior results, the tendon exhibited low energy return (~50%) at all amplitudes and frequencies, with modest increases at low amplitudes and high frequencies. Thus, tendons may be ineffective structures for energy recycling in small mammals.