During high-intensity exercise, lactate clearance occurs via which processes?

During high-intensity exercise, lactate clearance occurs via which processes?

• A. Excretion in urine.
• B. Oxidation in muscle and liver, gluconeogenesis, and lactate shuttle.
• C. Conversion to fat via lipogenesis.
• D. Lactate is only cleared during rest.

Answer: (B)

Lactate clearance during high‑intensity exercise happens by using lactate as fuel and by recycling it back to glucose, with lactate moving between tissues to where it can be used most efficiently. Lactate taken up by working muscle, the liver, and the heart can be oxidized to pyruvate and then enter the TCA cycle to produce energy. At the same time, the liver (and to some extent the kidneys) can convert lactate into glucose through gluconeogenesis, helping to maintain blood glucose levels. The lactate shuttle describes how lactate is transported from producing cells to other tissues with greater oxidative capacity, where it can be oxidized or used for gluconeogenesis. Urine excretion is not the primary clearance route during exercise, and lipogenesis is not a rapid mechanism for clearing lactate in this context. Lactate clearance is active during high‑intensity work, not confined to rest.

Lactate clearance during high‑intensity exercise happens by using lactate as fuel and by recycling it back to glucose, with lactate moving between tissues to where it can be used most efficiently. Lactate taken up by working muscle, the liver, and the heart can be oxidized to pyruvate and then enter the TCA cycle to produce energy. At the same time, the liver (and to some extent the kidneys) can convert lactate into glucose through gluconeogenesis, helping to maintain blood glucose levels. The lactate shuttle describes how lactate is transported from producing cells to other tissues with greater oxidative capacity, where it can be oxidized or used for gluconeogenesis.

Urine excretion is not the primary clearance route during exercise, and lipogenesis is not a rapid mechanism for clearing lactate in this context. Lactate clearance is active during high‑intensity work, not confined to rest.