Do This
Short, high-intensity cardio bursts

Not This
Steady-state cardio


In one Australian study, volunteers rode a stationary bike for either 40 minutes at a steady pace or 20 minutes of intervals, alternating 8 seconds of sprints with 12 seconds of easy pedaling.

After 15 weeks, the sprinters had lost three times as much body fat—including thigh and core flab. Bursts of speed may stimulate a fat-burning response within the  muscles, says lead researcher Ethlyn Gail Trapp, PhD. 

This is again more proof that flat land sprinting, and especially up a hill (my favorite) or a flight of stairs IS the best way to get in shape, lose excess body fat and have a great cardio-vascular system.  You can do this regardless of your age.  But if you're "out of shape" start by fast walking for 8 seconds and then a moderate walk for 12 seconds.  You'll easily build up in no time to a run and then an all out sprint.

By the way, in the "old days" heart doctors' proof that your heart was "in shape" was if you could walk 5 flights of stairs with very little problems.  Give that a try and see how you do.  If you can do it easily, you're good to go for those sprints.  If you can't, then I encourage you to see your cardiologist ASAP.