Q: When people say short intense cardio is more effective than long light cardio, what is the time span??? Say you jog lightly for 10 minutes nonstop. Would sprinting for 5 minutes straight have to same effect as the 10 minute light jog? I would rather do something fast that takes half the time rather than spend a long period of time on long running. Also, I am obese and am wondering if it would be bad to do short intense cardio rather then long light cardio? I am 15, 5'11, 220 pounds, male. I want to lose my man boobs and gut and fat all over my body. I am planning to eat right as in eating healthier. I am just not sure what to do for exercise that will be really effective. Thanx

A: Short intense cardio is a very good tool to lose fat and yes, I would recommend 5 minutes of fast running over 10 minutes of slow jogging. If you start out in untrained shape (like it sounds you are) and you can't run for very long, then 'short intense' may simply be jogging, but as your conditioning improves you'll be able to run faster and faster.

There's a few different types of cardio you can do:

• Traditional slow pace cardio. This is where you walk, jog, or run at a steady pace for well over 15 minutes and up to an hour. In this case you pick the pace that you can sustain for a very long time. If you do this, I recommend you keep it under 2-3 hours total per week.
• Fast pace running. Here you jog or run as fast as you can at the pace that you can sustain for only a limited time, anywhere between 3 and 15 minutes usually. You can do these bouts of fast-pace running 3-4 times per week and I recommend picking a pace you can sustain for about 10 minutes. Again, in the beginning this 10-minute pace may be quite slow for you but as your conditioning improve you'll be able to sustain faster and faster speed for 10 minutes.
• HIIT cardio. The effect this has on your body is actually closer to weight training (which is a great fat-burner) than to cardio. HIIT consists of alternating 30-second periods of all-out sprinting and walking. It can be done using any sort of activity -- from running to biking to swimming, though running is the most common. For example, a typical 4-minute HIIT session would look like this (after a warm-up): 30 seconds of all-out sprint, 30 seconds of relaxed walk, 30 seconds of all-out sprint, 30 second walk, 30 second sprint, 30 second walk, 30 second sprint, 30 second walk. That's it! You would do HIIT 2-3 times per week slowly increasing session length from 4-5 minute sessions in the first week to eventually 12-15 minute sessions. The key is to make those 30-second sprints to be truly as fast as you can possibly go.

So you can mix and match from these three types of cardio as you like -- I recommend giving HIIT and fast-pace running higher priority, though you can certainly do traditional slower pace cardio too if you like.

Besides cardio, it's very important to eat healthy and in moderate portions, as you have mentioned yourself. You may also want to start doing some weight training under adult supervision. And of course any other form of activity, whether mowing the lawn or playing pickup basketball games, is great for you too. When you jog or run or play basketball, remember that in the beginning you will not be able to sustain very fast pace for long and you may get runner's stitch in your side after not very long -- that's OK and you'll just need to stop at that point. You'll also likely to get very sore in the beginning of your exercise program -- that's also OK and you'll just need to wait an extra day or two till muscle soreness goes away before getting back to exercising. You'll learn to pace yourself and your conditioning will improve quickly, so don't let initial aches and pains scare you. Good luck!