[Age and changes in the body's resistance during adaptation to moderate muscular loads]

In 250 young and 24 adult albino rats, the organism resistance to a number of negative factors increased from the 14th to 30th day of life whereas the blood cell resistance decreased. Adaptation to moderate physical loads aided to a more intensive increase of the resistance, the effect being more obvious in elder animals in which the blood cell resistance increased as well. The findings revealed a close interrelationship between the organism's functional systems and its resistance.