Fig. 3. Sustained effect of eccentric exercise on isometric force-length characteristics for submaximally stimulated muscle. (A) Submaximal isometric force-length characteristics before (pre-exercise, closed symbols) and 80 min after a series of eccentric contractions (post-exercise, open symbols) (mean ± S.E.M.). Data were collected before (circles) and after (triangles) a potentiating tetanus, which caused post-tetanic potentiation (PTP). Exercise reduced submaximal force (obtained with a stimulation frequency of 60 Hz), whereas the potentiating tetanus raised force at most muscle lengths. (B) Submaximal isometric force-length relationship post-exercise, expressed relative to the pre-exercise values. Different effects of muscle length were found in the potentiated (triangles) compared with the non-potentiated (circles) condition. ^*Significant difference between non-potentiated and potentiated condition.