June 4, 2010 (Baltimore, Maryland) — New research presented here at the American College of Sports Medicine 57th Annual Meeting shows that circulating levels of brain-derived neurotrophic factor(BDNF) increase after intense resistance training, which might explain why exercise is effective at protecting and improving brain function.
The incidence of neurodegenerative diseases, like Alzheimer's disease, is lower in people who participate in endurance exercise on a regular basis, noted Joshua Yarrow, PhD, lead researcher and postdoctoral associate at the University of Florida in Gainesville.
He and his colleagues evaluated the effect of resistance training, including weightlifting, on levels of circulating neuroprotective molecules like BDNF.
They enrolled 20 college-aged men in a trial to determine whether repeated resistance exercise resulted in increased circulating BDNF at 1, 30, and 60 minutes after exercise. Serum BDNF was 23,304 ± 1,835 pg/mL at rest and increased 32% 1 minute after exercise (P < .05). Serum BDNF levels returned to baseline within 30 minutes and was 41% below resting levels 60 minutes after exercise (P < .01).
The study reveals that resistance exercise induces a robust transient increase in circulating BDNF concentrations. It has been shown that during endurance training, BDNF is produced in the brain. But BDNF is produced in many tissues, including musculoskeletal tissue and endothelial tissue. The production of BDNF peripherally with resistance training, which might then affect the brain, is important because we know that BDNF crosses the blood–brain barrier and can act within the brain," Dr. Yarrow said.
"Resistance exercise may essentially feed BDNF to the brain, which is why we see an increase in circulating levels immediately postexercise and then a decrease in protein within an hour," he added.
"This is important because we may be able to say that endurance exercise is not necessary for everyone who seeks the neuroprotective benefits of exercise. We may be able to tailor resistance training programs to optimize the exposure of neural tissue to neurotrophic factors like BDNF," Dr. Yarrow explained.
J. Carson Smith, PhD, associate professor at the University of Wisconsin, Milwaukee, offered a second interpretation of what happens to the BDNF that is released after resistance training. "In addition to the possibility that the BDNF circulates to the brain and crosses the blood–brain barrier to act in target tissues in the brain, it is possible that the BDNF is released peripherally and then is simply cleared from the circulation after a relatively short amount of time."
These findings have implications for the understanding of how both endurance and resistance exercise can lead to the release of neuromodulators that optimize the function of the nervous system from multiple perspectives, Dr. Smith said.
Increasing the presence of neurotrophins can have a positive effect on cognition, mood, emotions, and several other domains of brain function. Additional studies may focus on maximizing BDNF release from the peripheral tissue and studying the use of exogenous BDNF as a neuroprotectant for clinical use, the researchers said.
Dr. Yarrow and Dr. Smith have disclosed no relevant financial relationships.
American College of Sports Medicine (ACSM) 57th Annual Meeting: Abstract 735. Presented June 2, 2010
No comments:
Post a Comment