When there is a high energy demand, frequent variations in the energy demand, and a deficiency in oxygen, lactic acid is created and builds up in the muscle.
Muscle pH drops to between 6.4 and 6.6 during prolonged, severe exercise. The high H+ ion concentration does not seem to be the main factor limiting force creation; instead, the PCr level appears to be more important. High H+ concentrations can inhibit phosphofructokinase, although the inhibition can be effectively overcome by increases in the activators AMP and ADP. High H+ concentrations reduce PCr by directly affecting the equilibrium of creatine kinase and indirectly by raising ADP.
Learn more about concentration here-
https://brainly.com/question/10725862
#SPJ4