Which statement describes lactic acid buildup during exercise when oxygen is insufficient?

Which statement describes lactic acid buildup during exercise when oxygen is insufficient?

• A. Increased muscle temperature
• B. Lactic acid buildup leads to sore muscles
• C. Contraction rate increases with adequate oxygen
• D. Oxygen consumption decreases

Answer: (B)

When oxygen is limited during hard exercise, muscles switch to anaerobic glycolysis to keep making energy, so lactate (lactic acid) builds up quickly. This buildup, along with the accompanying hydrogen ions, lowers the muscle’s pH, causing a burning sensation and fatigue that athletes often associate with soreness. That direct link between lactic acid accumulation and the uncomfortable feeling in the muscles during intense effort is why this statement is the best fit for describing what happens when oxygen is insufficient. The other ideas describe general effects of activity or aerobic conditions rather than the specific outcome of lactic acid buildup under oxygen debt.

When oxygen is limited during hard exercise, muscles switch to anaerobic glycolysis to keep making energy, so lactate (lactic acid) builds up quickly. This buildup, along with the accompanying hydrogen ions, lowers the muscle’s pH, causing a burning sensation and fatigue that athletes often associate with soreness. That direct link between lactic acid accumulation and the uncomfortable feeling in the muscles during intense effort is why this statement is the best fit for describing what happens when oxygen is insufficient. The other ideas describe general effects of activity or aerobic conditions rather than the specific outcome of lactic acid buildup under oxygen debt.