Figure 3.

Typical effects of temperature on work loop shape. Mouse soleus work loop shapes at maximal power output at 15.3°C (broken line) and 37.4°C (solid line) in the same muscle preparation. Maximal power output was produced at a length change cycle frequency of 1 Hz at 15.3°C and 5 Hz at 37.4°C. Force was normalized to muscle cross-sectional area to calculate muscle stress and muscle length change was normalized to muscle length to calculate strain. Based on data presented in James et al. (2015). These work loop shapes demonstrate that at the higher temperature, there was more rapid force generation, greater maximal force, improved maintenance of force during shortening (likely to be at least partly due to an increased maximal shortening velocity, thereby altering the force–velocity relationship), and more rapid force relaxation.