Even if you've got the greatest abdominal workout in the world, it’s not going to slim your waist unless you also burn off the fat. Trust me...there are many of people out there who have great muscular tone and balance in the mid-section, but don't even know it because those nice abs are covered in a layer of fat. Remember, a combination of three factors is necessary for a slim waistline: a good abdominal workout, smart cardiovascualr exercise, and proper nutrition. In this article, I’m going to explain how to choose the proper cardio workout structure for burning the most amount of calories and burning the proper ratio of carbohydrates and fat.

When it comes to cardio, the question I probably receive most is: long and slow or short and fast? This question actually reflects the most important concept behind a good cardio routine. The truth is, it depends. Let’s begin by looking at total amount of calories burnt.

Say I ask you to travel a mile on foot. I don’t care how you do it – walk, jog, or run. Many exercise professionals will tell you that you’ll burn the same number of calories any way you do it, as long as you’re covering the same distance. This is simply not true. Studies have shown that the faster you cover that distance, the more calories you burn, period. There is a higher metabolic cost to moving quickly than to moving slowly. So you’re going to burn the most calories by pedaling, running, rowing, swimming, or doing any other cardio you do as fast as possible. The added bonus is that the faster you move, the higher your post-exercise metabolism becomes, meaning that you burn more calories throughout the day after your workout than if you had moved at a slower pace.

Here’s the catch – the faster you “move” across that mile, the more you rely on carbohydrates for energy, and the less you rely on fat. Although burning carbohydrates is beneficial, your body should also be learning how to efficiently use fat as an energy source. The “fat-burning” zone varies from person to person, but a good rule is that when breathing becomes labored or the muscles begin to burn, you’ve crossed the threshold to utilizing carbohydrate as a primary energy source. The basic science behind this is that it takes more oxygen to burn 1 calorie from fat than it takes to burn 1 calorie from carbohydrate, so as your body begins to work harder and get lower on oxygen, it turns more to carbohydrate as an energy source.

So here’s the application part. If you are pressed for time in your workout, go short and fast (i.e. 10-20 minutes, at an intensity level of 8-10). You will burn more calories, both in your workout and throughout the rest of the day. Ideally, however, if you have the time, you should also be incorporating long and slow cardio workouts into your routine (i.e. 20-60 minutes, at an intensity level of 6-8), essentially “training” your body to burn fat as a fuel. Often, I have my clients work in both zones by performing their short and hard cardio efforts prior to weight training on their “difficult” days, then performing their slow and long cardio efforts on their “easy” days. The added bonus is that the slow and long cardio efforts allow the body to recover more quickly from the previous day's difficult efforts, which means better results.

Let’s finish with a sample workout that will keep you in both zones during the same workout. This is an “interval” routine. Here’s how it works:

• 5 minute graded warm-up, gradually working up to a hard intensity by minute 5
• 1 minute hard-fast effort (labored breathing)
• 2 minutes easy-medium effort (conversation possible)
• 2 minutes hard-fast effort
• 1 minute easy-medium effort repeat 1x
• 3 minutes hard-fast effort
• 3 minutes easy-medium effort
• 4 minutes hard-fast effort
• 4 minutes easy-medium effort repeat 1x
• 5 minute cool-down, gradually working down to a very easy effort by minute 5.

If you sign-up to work more extensively with an online trainer at www.pacificfit.net, you can receive a series of workouts that include pre-written cardio intervals similar to the one above, along with a comprehensive resistance training routine and nutritional plan, complete with exercise photos and videos. Congratulations, you’re yet another step closer to slimming the waist.

About the Author

Head trainer Ben Greenfield runs the online training website Pacific Elite Fitness, and holds Bachelor's and Master's degrees in Sport Science and Exercise Physiology, as well as certifications from the National Strength and Conditioning Association as a Personal Trainer and Strength and Conditioning Coach (NSCA-CPT & CSCS). For over 6 years, Ben has coached and trained professional, collegiate, and recreational athletes, and helped hundreds of individuals achieve their personal fitness goals. For more information on online personal training and fitness, contact Ben at elite@pacificfit.net. www.pacificfit.net