A new study on mice has found that a protein in muscles plays a key role in recovery after exercise, and the researchers say it could potentially be used to improve sports performance.
The international team found that the protein – called brain-derived neurotrophic factor, or BDNF – signals to the body to replenish energy reserves following a workout.
This answers a long-standing question about the mechanisms behind how the body responds to and recovers from exercise.
Do you have questions about the biggest topics and trends from around the world? Get the answers with SCMP Knowledge, our new platform of curated content with explainers, FAQs, analyses and infographics brought to you by our award-winning team.
BDNF was initially identified in the brain, where it is vital for functions such as forming memories, moods, and the growth of neurons.
Scientists later realised it could also be found in tissues other than the central nervous system – the brain and spinal cord – but its roles elsewhere were not clear.
Chan Chi-bun, an associate professor at the University of Hong Kong’s School of Biological Sciences, led the study looking at the protein’s functions in skeletal muscles – the muscles that control movement.
“In our group, we used a genetically engineered mice model,” Chan said. “We removed all the BDNF proteins in the skeletal muscles but not in other parts of the body.”
He said their previous research had found that mice without the BDNF proteins became obese more easily and could not run as well as normal mice.
In the latest study, BDNF was found to have a role as a signal for the body to refuel energy sources in muscles after exercising.
“Our findings reveal that BDNF is an essential myokine for exercise-induced metabolic recovery and remodelling in skeletal muscle,” the team wrote in an article published in the peer-reviewed journal Science Signaling on Thursday. Myokine is a signalling molecule released by muscle cells.
“Chronic activation of the BDNF signalling in the skeletal muscle will not only ameliorate the health condition of obese subjects but also improve exercise endurance in normal individuals,” the scientists wrote.
The team included scientists from HKU, the Institute of Materia Medica at Peking Union Medical College, the University of Massachusetts Medical School and Hong Kong Baptist University.
Age-related muscle loss: why it happens and how to deal with it
“After we exercise, we will feel fatigued,” Chan said. In a healthy body, working out uses up energy reserves in muscles – including glucose and lipids – and they have to be replenished to continue exercising.
He said the body generated more BDNF after exercising to tell skeletal muscles that it was time to refill.
“Using knockout mice [without the BDNF proteins], we found that they have difficulties in refilling these kinds of substances, particularly lipids,” he said, adding that exercise performance fell if they did not refuel.
The study found that when normal mice were given a BDNF mimetic – which is found naturally in plants – their stamina improved.
“We put it into drinking water, which the mice could drink whenever they wanted, for three months,” Chan said. “They could run longer, meaning they had better exercise stamina.”
The team also found that BDNF played a role in regular training to improve performance.
“If you keep training for running, after several times you can run longer than before,” Chan said. “This is what we call adaptation of skeletal muscle.”
Why a cancer-causing stomach bacteria is infecting fewer people in China
For the study, the mice underwent treadmill sessions at a speed of 12 metres per minute, five days per week for four weeks.
“We gave the same training protocol to the knockout mice and the normal mice,” Chan said. “But their exercise performance did not improve like it did for the normal mice.”
Chan said the findings could potentially have applications for human health, suggesting the BDNF mimetic could be used as a supplement – like taking vitamins – to help athletes shorten their recovery time between training sessions, and to help elderly people maintain muscle function.
More from South China Morning Post:
- Gut bacteria could play a role in eye disease, China-UK study finds
- Beak power: how a toy that stumped Einstein is inspiring Chinese scientists to search for cleaner energy
- New US research finds no brain injuries among ‘Havana Syndrome’ patients
For the latest news from the South China Morning Post download our mobile app. Copyright 2024.
