Researchers at the University of Southern Denmark found high-intensity interval training is effective at boosting muscle mitochondria.
Mitochondria is a big name for a very small part of almost every human cell. Their importance cannot be overstated, so finding ways to help them do their job is a worthwhile endeavor. Researchers at the University of Southern Denmark found high-intensity interval training is effective at boosting muscle mitochondria.
Mitochondria are the parts of the cell that break down energy. It's their job to do things like produce energy from the food we eat, power the production of the molecules we need to live and to regulate aging.
The scientists in the study wanted to know what effect eight weeks of high-intensity interval training would have on the mitochondria in muscles. They realized the training not only increased the number of mitochondria, but also expanded the active membrane, called the cristae, inside them.
"We analyzed muscle samples from our study participants," said Martin Eisemann de Almeida. "We were able to measure that the number of mitochondria had increased after eight weeks of training and, importantly, our measurements showed that the active membrane inside the mitochondria had also expanded. So training does not just create more power plants but more efficient ones."
The results show that exercise has the ability to improve the ability for muscles to produce energy. This effect was seen not only in healthy study participants, but also in those who were overweight and those with type 2 diabetes.
That's good news for those with type 2 diabetes as it was previously assumed that the muscle's ability to adapt to training was impaired.
The relatively small sample size of 48 men was divided into three groups: 15 with type 2 diabetes, 15 overweight individuals without diabetes and 18 people of normal weight. They had small samples taken from their muscles before and after the eight-week training period.
"We spent a year manually analyzing around 11,000 individual mitochondria," Eisemann de Almeida said. "This made it possible to detect a change of around 7% in the active membrane—a difference that previous training studies were not able to demonstrate."
The results showed the inner structure of the mitochondria changed in a way that allowed them to better supply energy.
"The study also does not tell us whether the changes are maintained in the long term, but it provides new evidence that muscle mitochondria are more adaptable than previously thought," Eisemann de Almeida said. "The changes can most likely be maintained or further improved with continued training, while stopping training will probably cause the mitochondria to return to their baseline level."
