Final answer:
Under low oxygen, skeletal muscle produces lesser ATP due to a reliance on anaerobic glycolysis, which leads to muscle fatigue and stiffness.
Step-by-step explanation:
Under low oxygen conditions, skeletal muscle will generate lesser ATP. ATP is required for muscle contractions, particularly to detach the myosin head from the binding sites on actin. Without sufficient oxygen, the muscle cannot undergo aerobic metabolism efficiently, which is responsible for the majority of ATP production during prolonged muscle activity. Instead, the muscle relies on anaerobic glycolysis, which produces lactic acid and significantly less ATP. Therefore, under low oxygen conditions, the skeletal muscle generates lesser ATP, which can lead to muscle fatigue and the inability of the myosin heads to detach from actin, eventually contributing to muscle stiffness.