Scientists have shed new light on the effects that high-intensity interval training (HIIT) has on human skeletal muscle, according to a study in men published in eLife.
The findings of the study show that HIIT boosts the amount of protein cells in skeletal muscle that are essential for your metabolism and for your muscles. These results could explain beneficial effects of HIIT on metabolism and pave the way for additional studies exploring how exercise impacts these processes within your body.
For the study, the team at the Department of Nutrition, Exercise and Sports at the University of Copenhagen recruited eight male volunteers to complete five weeks of high-intensity cycling training. The men worked out three times per week, a target rate of more than 90% of their maximum heart rate followed by a two-minute rest. They repeated this pattern every workout. Using a technique called mass spectrometry, the team analysed changes to the composition of over three thousand protein cells in tissue samples collected from the participants’ thighs before the study and then again after they completed the training.
“We wanted to understand how HIIT exercise alters the muscles’ protein content and how it regulates the activity of these proteins through a chemical reaction called acetylation,” says author Morten Hostrup, Associate Professor. “Using state-of-the-art proteomics technology, our study provides new information about how skeletal muscle adapts to exercise training.”
The analyses showed an increase in the production of proteins used to build mitochondria, which produce energy in cells, and in proteins related to muscle contractions. They also saw changes in the amount of proteins that reduce the skeletal muscle’s calcium sensitivity, which is essential for muscle contractions.
The results confirm some well known changes to skeletal muscle proteins that occur after exercise, as well as identify new ones. The work also suggests that HIIT exercise may contribute to boosting metabolism, and is an exciting step forward in looking into how HIIT training can positively impact our bodies and their processes for a healthier lifestyle!