The lower the intensity of the activity or exercise the smaller the number of calories burned per unit of time. For example, you can burn more calories in 15 minutes of bicycling at a high intensity level than you can in 45 minutes of easy walking.

Another downside to walking is that because it's generally low intensity it results in only a small increase in metabolism that will only last approximately 1-2 hours after the walk. On the other hand, metabolism increases are larger and last longer (4-24 hrs or more) when you perform high intensity cardio workouts.

Low intensity exercise like walking does not deplete muscle glycogen levels and therefore, later that day if you have excess calories they will likely be stored as body fat whereas if you deplete the glycogen the excess calories will primarily be stored in the muscles.

So why then do so many fitness and health experts recommend walking for weight loss? One reason is that people don't want to hear that they have to work hard so they figure some activity is better than none. Another reason is that the body burns more fat for fuel when exercising at an easy pace, however, the total amount of energy used is so small that you end up burning off little body fat. That's also why when you choose the "fat burning" program on your treadmill or bike it has you exercise at any easy level. Yes, you're burning fat, but so little that you'd have to exercise at that easy pace for hours and hours each day.

High intensity cardiovascular/aerobic exercise is much more effective in burning off the excess body fat. In fact, several studies have been done to prove this. In one study they compared one group who did moderate level aerobics for 45 minutes with another group who performed high intensity workouts for 15 minutes. They did before and after fitness testing including body fat analysis and found that the group who performed the high intensity aerobics lost nine times as much body fat!

Want more proof?

Compare the bodies of a walker, marathon runner, and sprinter. If you are not familiar with what a sprinters body looks like, it is very muscular and has little body fat while on the other hand the body of a walker will likely have the opposite, little muscle and more fat. The sprinter does little or no low intensity exercise and does primarily short hard bursts of work while the marathoner overtrains so much they burn off both the body fat and the muscle and that's why they tend to look almost sickly thin.

So what should you do then if your main objective is to shed those excess pounds of body fat?

Two things:

I know some of you by now are saying "I can't do high intensity exercise, I have a bad knee" and don't worry, I have a solution for you. The good news is that high intensity is all relative to you and your current fitness level. For example, fast walking up and down hills may be high intensity for you... it all depends. So don't think that you have to start running or something like that. Just slowly start to increase the intensity of your cardio workouts while also maybe decreasing the time because you can either work hard or you can work long.

Also, you can make almost any activity or exercise high intensity.... here are a few examples:

• increase your speed

• use an incline or hills

• increase resistance

• perform intervals ( the most effective method)

Obviously, some exercises/activities or better suited than others but the point is if you want to burn more fat and make your workouts as productive as possible you need to increase the intensity.

To learn more about high intensity cardiovascular exercise please check out the following articles:

• Forget the Fat Burn Zone - http://www.achieve-fitness.com/forget.htm

• In Search of the Ideal Aerobics Routine - http://www.achieve-fitness.com/ideal.htm

• Heart Rate Guidelines - http://www.achieve-fitness.com/cardio.htm

Be sure to also check out my Burn Fat FAST! ebook and audio program here: http://www.burn-fat-fast.com - it covers everything from cardiovascular training to strength training to nutrition and more.

As with any changes to your fitness program be careful and don't over do it. Just because high intensity workouts burn more fat, don't think that you'll get even better results by doing it everyday - that will quickly lead to over-training and a loss of muscle which will only make it even harder to burn off the fat.

So if your primary goal is fat loss, don't waste your time walking and instead focus on progressive, high intensity cardio to maximize the effectiveness of your workouts.

About The Author

Jesse Cannone is a certified personal trainer and author of the best-selling fitness ebook, Burn Fat FAST. Be sure to sign up for his free email course as it is full of powerful weight loss and fitness tips that are guaranteed to help you get the results you want. http://www.burn-fat-fast.com

http://www.burn-fat-fast.com