I work in a school. Every morning during the last couple weeks of school, I would pass the gym on the way to the main office and see a couple of coworkers walking laps in the gymnasium. Let me be the first to say that I admire the fact that they are willing to do something beyond the scope of the day-to-day in what appears to be a quest for better health.

The point of the matter, however, is this: in order to burn any significant amount of fat, there has to be a substance present that will stoke the fire of the metabolism. Just walking around a gym, while better than nothing at all, doesn't generate enough intake of this necessary fat-eliminating substance.

That substance is oxygen.

Studies have shown that just breathing deeply is enough to start the process of burning calories. The act of sitting in a chair and breathing deeply for 10 minutes will burn more calories than sitting in the chair and breathing normally. Aerobic exercise, in addition to raising oxygen uptake, raises the metabolism in order to speed more oxygen to the extremities.

Now, I could go into a lot of technical discussion about the interaction of oxygen with references to ATP (adenosine triphosphate) and such, but I don't think it really matters that you know the specific details about HOW oxygen works. I don't know HOW my car works, for example, but I'm pretty glad that I can drive it from home to the gym. So let's forget the details and just understand the relevant points - oxygen helps burn fat, and aerobic exercise permits effective oxygen uptake.

Proper breathing is a reason that practitioners of such activities as Yoga and Tai Chi are usually such lean individuals. The focal aspect of Yoga and Tai Chi training is breathing. Breathing = more oxygen.

Sustained activity that generates sufficient oxygen uptake, whether it be deep breathing or cardiovascular exercise, is a requirement for fat burning.
If you're fairly new to the world of exercise and fitness, understand this simple point: walking casually around the gym is nice, but it's likely not going to have the desired result of trimming body fat. If the lean and strong look is what you desire, running suicides on the basketball court will really make a body seriously breathe.

And that is a plan for success.

Be well!