Men may lower their risk of COPD development and COPD mortality later in life if they practice good fitness habits in middle age, according to data from a new study.

This study included more than 4,700 healthy middle-aged men in Denmark who were recruited between 1970 and 1971. Their average age at the time was 49.

The men were tracked for up to 46 years, with overall follow-up ending in 2016. Compared to those who had low heart-lung fitness in middle age, COPD risk was 21% lower in those who had normal fitness and 31% lower in those whose heart-lung fitness was high.