Exercise, extracellular vesicles and NAMPT

Exercise and communication between tissues

This study examined the release of extracellular vesicles after exercise and their content of extracellular NAMPT, or eNAMPT. It did not test whether oral NMN supplementation improves physical performance.

NAMPT is involved in a pathway that produces NMN for NAD+ biosynthesis. Extracellular vesicles are small structures released by cells that can carry molecules between tissues.

What was observed after exercise

The researchers reported an increase in circulating small extracellular vesicles after moderate-intensity exercise. Their eNAMPT content also changed, with the largest response described in younger participants with higher aerobic fitness.

Responses differed with both age and fitness. Older fit participants and younger less-fit participants showed more limited increases, while the archive describes no increase in the older less-fit group.

The recipient-cell experiment

Vesicles isolated after exercise were applied to recipient cells in laboratory experiments. They altered NAD+ abundance or SIRT1 activity compared with vesicles collected before exercise.

This supports investigation of a possible route of tissue-to-tissue signaling. It does not establish that a measured vesicle response alone explains all of the health effects of exercise.

Why the distinction from NMN matters

The presence of NAMPT in the pathway provides a biological connection with NMN and NAD+. However, exercise-induced vesicle release, direct enzyme changes and oral precursor supplementation are different interventions.

The study's observations therefore cannot be used as direct evidence that an NMN supplement reproduces exercise or increases stamina in a particular person.

Conclusion

The research suggests that age and fitness may influence an exercise-related signaling mechanism involving extracellular vesicles and eNAMPT. Further work is needed to determine how those signals contribute to whole-body physiology.

Cited paper: Exercise increases the release of NAMPT in extracellular vesicles and alters NAD+ activity in recipient cells.