Why does regular endurance training result in less disruption of the blood pH during submaximal work?

• A. They have higher buffering capacity due to bicarbonate.
• B. There is no difference in lactate production between trained and untrained individuals.
• C. Endurance-trained muscles produce less lactate and H+.
• D. They produce more lactate and H+.

Answer: (C)

Regular endurance training increases the muscle’s oxidative capacity, with more mitochondria, higher enzyme activity, and better capillary supply. At submaximal effort, this shift lets energy come more from aerobic metabolism rather than rapid glycolysis, so less pyruvate is diverted to lactate. Since lactate production is linked to hydrogen ion release, producing less lactate means fewer H+ ions accumulate, helping keep blood pH more stable. Training also enhances lactate and H+ clearance through better transport and disposal pathways, though the main effect is reduced production of lactate and H+.