Bold claim: Tiny particles in our blood may be key couriers for hormones, reshaping how we understand exercise, brain access, and overall health.
Researchers at Touro University Nevada have identified extracellular vesicles (EVs) as major players in transporting a hormone precursor called proopiomelanocortin (POMC) through the body. POMC can be processed into several hormones, including endorphins (the so-called runner’s high) and ACTH, which helps regulate the body’s stress response. The team used exercise to trigger changes and explore how POMC and EVs interact.
The study, published in Proceedings of the National Academy of Sciences (PNAS), shows that intense exercise increases the amount of POMC carried by EVs by about fourfold. As the study’s first author, Mark Santos, Ph.D., notes, this isn’t merely an “exercise effect.” It reveals a new biological mechanism: the stress from exercise temporarily turns EVs into hormone transport shuttles circulating in the bloodstream. This finding points to several potential effects, including how exercise influences energy balance, mood, immune function, and even how certain drugs circulate in the body.
In lab tests, EV-bound POMC crossed human blood vessel barriers more efficiently than POMC alone, including the blood-brain barrier. Since POMC must be converted into mature hormones to trigger responses in the brain—a region notoriously hard to reach—further work is needed to understand how the exercise-driven rise in POMC affects brain activity and behavior.
Aurelio Lorico, MD, PhD, a co-senior author and professor of pathology at Touro, emphasizes the study’s broad implications. He suggests that EVs carrying POMC could influence pain management, metabolism and obesity, inflammation, and the body’s stress response. The authors acknowledge that more research is needed to translate these findings into practical interventions, but the potential is wide-ranging.
What does this mean for you? Exercise may do more than burn calories or build muscle—it could modulate the distribution and effectiveness of critical signaling molecules through EVs. This could eventually inform new strategies for enhancing mental health, regulating energy balance, or improving drug delivery to the brain.
Controversy-friendly takeaway: If EVs can ferry POMC and cross the blood-brain barrier more efficiently during exercise, could tailored workouts be leveraged to optimize hormone signaling for specific health outcomes? And does this imply that some benefits of exercise are contingent on how effectively EVs transport these signals, rather than just the activity itself? Share your thoughts in the comments: Do you think this could change the way we design exercise programs or treat conditions like obesity, depression, or chronic pain?
Source:
Hightower, Cheryl E. et al, Physical exercise increases binding of POMC to blood extracellular vesicles, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2525044122.
