Excessive exercise promotes the biological aging of middle-aged women, according to recent research.

Shin Yun-a, professor of physical education at Seoul National University released a paper regarding the effect of heavy exercise on middle-aged women's telomeres, an aging indicator in cells.

Shin discovered telomeres got shorter when women in middle age do excessive exercise.

For the study, she sampled 10 women in their 30s to 60s, who had not exercised in the past six months. After doing heavy exercise that required them to use from 60 to 80 percent of their maximum oxygen uptake, their telomeres got shorter.

Shin explained that after heavy exercise, the women's lipid peroxidation, that damage cells, rapidly increased. Excessive exercise also caused superoxide dismutase (SOD) deactivation -- SOD is an enzyme protecting cells against aging.

“Although regular and proper exercise is helpful, sudden and heavy exercise requires excessive oxygen consumption, causing aging,” she said.