The sooner the better, but also better late than never when it comes to exercise.

Researchers from three studies have found compelling evidence that middle age isn’t too late to get active and reap the reward of better health.

As long as they started between the ages of 45 and 64, results from one study showed that participants who exercised 30 minutes, 4-5 days a week – including one high-intensity workout – for two years reversed affects on the health of their heart from a previously sedentary lifestyle.

Starting at an average age of late 40s, participants who maintained or increased their cardiovascular fitness over four years had a 40 per cent lower mortality rate according to another study of more than 6,000 people.

And with an average age of 71, 139, 000 people were monitored for 13 years to determine how walking affected mortality rates. Among those who walked at up to two hours a week, the mortality rate was 26 per cent less than participants that reported little to no activity. And those who walked two to six hours a week had 36 per cent lower mortality than participants in the two-hour cohort.

In their conclusion, the walking study’s researchers offer pretty easy advice to action: “Walking is simple, free, and does not require any training, and thus is an ideal activity for most Americans, especially as they age.”

Throw in a 30-minute circuit training session once a week – check with your doctor first, of course – and it seems we can start improving our final outcome.