Figure 2. Effect of 24 mm lactic acid on the force–velocity curve of rat soleus at 30°C.

A, force–velocity curves fitted to data points from a representative muscle incubated at 4 mm K⁺ without lactic acid (pH 7.45, control), 4 mm K⁺ with 24 mm lactic acid (pH 6.8) and finally at 4 mm K⁺ again (pH 7.45, post control). B, same data as above but expressed as power versus velocity and fitted to power–velocity curves using the parameters obtained from the Hill fits in the top panel.