Effect of a training session of endurance running on anserine and carnosine contents in fast and slow muscles of young rats.

The effect of a training session of endurance running on anserine and carnosine contents in extensor digitorum longus (EDL) and soleus muscles (SOL) of rats was studied during aging from 5 to 20 weeks. During aging from 5 to 14 weeks, the endurance training suppressed the developmental increases of body, EDL, and SOL weights in a similar way and of the anserine and carnosine contents in the two types of muscles to a greater extent than their weights. This indicates that the suppression of the developmental increase of the anserine and carnosine contents in the muscles by the training is not only due to their slow growth, but also to some, probably adaptational change of the muscle to the training. The suppressing effect of the training during the subsequent aging appeared to be equal to or even weaker than the before in these muscles.