Cardio

Physical activity that uses large muscle groups and increases your heart rate such as walking, jogging, swimming, riding a bike, etc. that is sustained for at least 20 minutes is considered a cardio-fitness exercise.

To maintain cardio-fitness you need at least 2 hours and 30 minutes a week of moderate cardio activity.

or…

At least 1 hour and 15 minutes a week of vigorous activity.