A recent study involving High-Intensity Interval Training -or HITT- has provided new information regarding how human skeletal muscle adapts to exercise training and affects metabolism.
Exercise alters the muscles' protein content and regulates these proteins' activity through a chemical reaction called acetylation. Acetylation is a chemical reaction that occurs when a member of the small molecule group, acetyl, combines with other molecules and can affect the behavior of proteins.
The scientists involved brought in 8 healthy but untrained male volunteers to participate in a 5-week study of high-intensity cycling training. For three days every week, the volunteers finished four minutes of cycling at a target rate of more than 90% of their maximum heart rate, followed by a two-minute rest, and repeated this process 4 to 5 times a session.
An analysis of the study showed an increase in the production of the proteins used to build mitochondria, which produce energy in cells and proteins related to muscle contractions. They also identified an increase in acetylation of mitochondrial proteins and enzymes involved in cellular energy production. And they observed changes in the number of proteins that reduce the skeletal muscle's calcium sensitivity, which is essential for muscle contractions.
They also discovered that reduced calcium sensitivity might explain why it can be more challenging for muscle contraction to occur after an athlete becomes fatigued. The work also suggests that exercise-induced changes in regulating proteins through acetylation may boost metabolism.
These findings suggest that HIIT boosts the number of proteins in skeletal muscle essential for energy metabolism and muscle contraction and chemically alters vital metabolic proteins. These results may explain the beneficial effects of HIIT on metabolism and pave the way for additional studies exploring how exercise impacts these processes.
Exercise has many benefits, including preventing and treating metabolic disease, most likely because of the change in the usage of energy by skeletal muscle. Still, further research into how exercise helps improve metabolic health is needed, but it seems safe to say that exercise overall is beneficial to all.
Sources: eLife, ScienceDirect, Science Daily
