Figure 2. Diagram depicting the Krebs cycle in more depth. The red area highlights the limiting enzyme α-ketoglutarate and the increased demand for NAD at this point

From

The Proposed Effects of Nicotinamide Adenine Dinucleotide (NAD) Supplementation on Energy Metabolism

Benjamin David French

American Journal of Sports Science and Medicine. 2015, 3(5), 96-107 doi:10.12691/ajssm-3-5-3