@ProfTimNoakes @drjamesdinic Hi Tim. I believe the anaplerotic theory was dispelled a while ago, and few refer to it now. What's been show in several studies is that adenine nucleotide loss & increases in IMP occur with prolonged exercise, most prominently in glycogen depleted fibres... @ProfTimNoakes @drjamesdinic The increase in IMP is also attenuated with CHO ingestion. It's true that the mechanism isn't exactly clear, but those findings are consistent with the view that there is at least a temporary mismatch between oxidative ATP resynthesis and ATP usage...