EDL and soleus muscle force vs. frequency relationships.

<p>Muscle contraction was stimulated with increasing frequencies from 1–130 Hz to determine the force-frequency relationship. A) EDL muscle absolute force. <i>Inset</i>: Raw data traces of 1 Hz, 20 Hz and maximal tetanic contractions (* denotes P<0.025, HMB + <i>β</i>-alanine compared to control diet; ^<b>a</b> denotes P<0.025, <i>β</i>-alanine compared to control diet). B) EDL muscle specific force (* denotes P<0.025, HMB + <i>β</i>-alanine compared to control diet). C) Soleus muscle absolute force. D) Soleus muscle specific force. (EDL: Control-n = 24 muscles, HMB-n = 23 muscles, <i>β</i>-alanine-n = 24 muscles, HMB + <i>β</i>-alanine-n = 24 muscles. SOL: Control-n = 23 muscles, HMB-n = 24 muscles, <i>β</i>-alanine-n = 24 muscles, HMB + <i>β</i>-alanine-n = 24 muscles).