Effect of exercise on glycogen level in muscles and liver in rats

The effect of exercise of glycogen level in skeletal muscles and liver was studied in Wistar rats. The previously untrained animals were subjected to one-time exercise in form of swimming in water at 32 degrees C for 10, 20 and 30 min. The glycogen level in the muscles (in g per 100 g of tissue) fell down during the first 10 minutes of the exercise by a mean value of 0.45 g. During the following 10 minutes the decrease was smaller amounting on the average to 0.1 g. After 30 min the glycogen level in the muscles was about 0.1 g/100 g of tissue. Respective falls of glycogen level in the liver were on the average 0.99 g and 0.40 g/100 g of tissue. After 30 min of exercise the glycogen level in the liver was 1.2 g/100 g of tissue. The fall of glycogen level in the muscles was similar at all times during exercise in all animals, but in the liver fairly significant differences were observed in the first 10 min between individual groups of rats. Later on during exercise the differences in the liver glycogen falls decreased.