Reason behind effectiveness of short, intense physical exercise found

Swedish researchers have uncovered one reason behind the effectiveness of short but intense physical exercise, they announced on Tuesday.

For recreational exercisers, a few minutes of high-intensity training match the results achieved with more time-consuming routines by altering how muscle cells handle calcium, a study conducted at Stockholm's Karolinska Institutet has found.

"Our study shows that three minutes of high-intensity exercise breaks down calcium channels in the muscle cells," Hakan Westerblad, a professor of physiology and pharmacology, said in a statement.

Intense exercise leads to the formation of new mitochondria in the muscle cells, which increases endurance, Westerblad said.

The study, published this week in the journal Proceedings of the National Academy of Sciences, had male subjects do 30 seconds of maximum-exertion cycling followed by four minutes of rest and repeat the routine another five times.

Muscle tissue samples then showed an increase of free radicals, which oxidize proteins in muscle cells, the researchers said.

Meanwhile, antioxidants such as vitamins E and C thwart the breakdown of the calcium channels, leading to a lessened response to physical training, the university announced.

That finding "might explain why (antioxidants) can weaken muscular response to endurance training," Westerblad said. Endit