Tricarboxylic acid cycle intermediate pool size and estimated cycle flux in human muscle during exercise

We examined the relationship between tricarboxylic acid (TCA) cycle intermediate (TCAI) pool size, TCA cycle flux (calculated from leg O2 uptake), and pyruvate dehydrogenase activity (PDHa) in human skeletal muscle. Six males performed moderate leg extensor exercise for 10 min, followed immediately by intense exercise until exhaustion (3.8 +/- 0.5 min). The sum of seven measured TCAI (SigmaTCAI) increased (P