The way our bodies turn food into energy, or metabolize, depends on how much we eat (or don’t) and how much physical (and mental) activity we exert. Our ability to adapt metabolically to these different situations allows our body and mind to get the most energetic bang for nutritional buck.
And at the center of metabolic adaptation is the molecule fundamental to cell function and survival called nicotinamide adenine dinucleotide (NAD+). Because our vitality and ability to adapt metabolically is tied to NAD+, there’s been a push to find effective NAD+ precursors that boost NAD+ levels. Although one precursor nicotinamide riboside (NR) has emerged as a dietary strategy to elevate NAD+ in animals, whether NR can elicit a similar response in humans has been unclear.
Now, researchers from the University of Birmingham in the UK and the Garvan Institute of Medical Research in Australia showed that NR supplementation (1000 mg/day) for one week did not alter human whole-body metabolism before, during, or after a one-hour aerobic workout. This acute NR supplementation neither augmented human skeletal muscle signaling implicated in metabolic adaptation to endurance exercise — in this case, using a cycling ergometer or stationary bike — nor affected the function and levels of mitochondria, the cell structures in charge of metabolism.