Final answer:
The activity of calcinurin, calmodulin kinase, and AMP kinases increases within minutes after an acute endurance exercise training session, which is essential for muscle adaptation and not to be confused with CPK levels or DOMS.
Step-by-step explanation:
Following an acute bout of endurance exercise training, the rise in the activity of calcinurin, calmodulin kinase, and AMP kinases occurs within minutes following the exercise session. These enzymes play crucial roles in the adaptation of muscles to endurance training. Calcinurin and calmodulin kinase are involved in the calcium signaling pathways which are important for muscle contraction and growth, while AMP kinase is a key regulator of energy homeostasis during exercise.
It's important to note that the increase in activities of these enzymes is distinct from other physiological measures such as creatine phosphokinase (CPK) levels, which elevate in plasma over a longer period (1-2 days) and are indicative of muscle damage, not immediate adaptation.
Delayed onset muscle soreness (DOMS) is another phenomenon related to exercise, occurring one to three days post-exercise, which is now understood not to be caused by lactic acid buildup. Lactic acid disperses fairly rapidly from muscle tissues and does not seem to account for the sustained pain of DOMS.