We all know physical activity is good for us. But just how good is a debate that has finally been put to rest.

A recent study published this week in the European Journal of Preventive Cardiology, analyzed over 45 years of data in middle-aged men. Researchers concluded that the impact of low aerobic capacity on risk of early death is second only to smoking.

The study included almost 1,000 men who at 54 years old performed an exercise test, a max exercise test and and max oxygen uptake with a device you blow into.

After the initial exercise test in 1967, the men followed up with researchers regularly until 2012 (when the men were 100 years old).

When looking at how the men tested in VO2max, the bottom third of men had a 40% higher risk of early death than the top third. And the risk associated with low predicted VO2max was evident throughout four decades of follow-up.

How much physical activity do you need?

According to the CDC, adults need at least 2 hours and 30 minutes of moderate-intensity activity a week (brisk walking counts!) and muscle-strengthening activities on 2 or more days a week that work all major muscle groups.

2 and half hours sounds like a lot of time, but it can even be done 10 minutes at a time!

How much can you do for ever greater health benefits?

The CDC recommends 5 hours of moderate-intensity aerobic exercise and 2 or more days of strength training, or 2 and a half hours of high-intensity exercise and strength training for 2 or more days a week.