3 miles = 2 miles + 1 mile. However, 4 miles = 2 miles + 1 mile + oh-you-gotta-be-kidding-me miles. In other words, the idea of running, jogging, even just trudging 4 miles is very intimidating. It's a lot farther than 3 miles.

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You can do any activity that you like and can stick with it because if you enjoy it you are more likely to do it. Running, Swimming and cycling are the most popular cardio exercises that almost everyone has access to. Obviously, all three activities can get you where you want to go health wise and are very good calorie burners. The purpose of this article is to compare the effects of all three programs of cardio training.