Any exercise is better than none,

By Heather Newman
Detroit Free Press
So how much exercise do you actually need to be fit

The American College of Sports Medicine and American Heart Association suggest moderately intense cardiovascular exercise 30 minutes a day, five days a week; or vigorous exercise 20 minutes a day, three days a week.

They also recommend eight to 10 strength training exercises each week, with each one done for eight to 12 repetitions.