How Can I Burn The Most Calories In The Shortest Time?

Cardiovascular exercise has two distinct categories: aerobic exercise and anaerobic exercise. Both of these terms refer to, and are directly related to, the frequency at which your heart is beating. Aerobic exercise(with oxygen) is your long-term energy source and requires the utilization of oxygen. The term anaerobic(without oxygen) is your short-term energy source due to oxygen debt. The molecule ATP is your primary energy source. Due to the lack of oxygen, your body can only sustain this high level of cardiovascular output for a brief period of time.

A perfect example of these two categories of exercise is best illustrated in the 400-yard dash or a two-to-three minute maximal-effort sprint. Approximately 50 percent of the energy comes from aerobic sources and 50 percent from anaerobic sources. However, in a ten-minute maximal-effort activity, the anaerobic component drops to only 15 percent due to lack of oxygen. Basically what this demonstrates is that with aerobic training the muscles become more efficient in burning fat, and fatigue is slower because glycogen and oxygen are not used as quickly during exercise.

The reason for defining these two forms of exercise is so you understand that most of your cardiovascular exercise will be done in an aerobic state. However, going into and out of the anaerobic state will help increase your cardiovascular stamina and endurance, thus strengthening your heart and raising your overall fitness level. In essence, you want to do aerobic exercise that is just out of your comfort zone and every once in a while push yourself even further for short spurts. This type of cardiovascular training allows you to do what I call "raising the bar": you need to continually strive to push yourself past your self-imposed limitations to achieve your weight loss goals, make consistent progress, and stay motivated to exercise regularly.

The level at which your body burns calories most efficiently will vary, as will how long you can sustain that level, depending upon your gender, age, and fitness condition. The cardiovascular and respiratory systems work together to transport oxygen throughout the body. This process is called oxygen uptake or consumption. Oxygen consumption is called VO2. Maximal oxygen consumption (VO2 max) is the best way to gauge cardiovascular fitness. It is the highest rate of oxygen transport at a person's maximal physical exertion. Someone who is not very fit may be able to sustain an intensity level of only 40 percent of VO2 max, whereas someone who is in mediocre shape may be able to sustain 60 percent of VO2 max and a very fit person may sustain 80 percent ofVO2 max. Therefore, the best intensity level for you is the level that you can sustain for an extended period of time that challenges you throughout most of the entire cardio session. The key is to raise that intensity level gradually and continually, thus forcing you and your body to work harder.

There is an equation that determines what your maximum heart rate should be. I will walk you through this equation so that you can determine where your most efficient levels are. You may want a calculator to help determine these numbers. I also suggest that you write these numbers in your journal so that you can refer back to them later and keep track of the changes in your heart rate levels. At most, the human heart can beat only 220 times per minute. Each year you are alive, your maximum heart rate gets lower and lower. To determine what your maximum heart rate should be, simply subtract your age from 220. For instance, if you are 40 years old, your maximum heart rate would be 180 (220 - 40 = 180). To achieve maximum fat burning efficiency, you should work toward keeping your heart rate around 75 percent of your VO2 max for the majority of your cardio session. Let's determine what that means in terms of your personal target range. Using the example of a person who is 40 years of age, multiply the heart rate of 180 by .75. The ideal aerobic level for a 40-year-old would thus be about 135 heartbeats per minute. It may take a while to get to that level, but don't get discouraged. You are still burning calories, even if you are working at a lower level.

When your heart rate nears 80 to 85 percent of your maximum, you begin to move into the anaerobic state. When you reach this thresh old, you can sustain it for only a brief period of time. Throughout your cardio sessions, you will primarily be in your aerobic zone. However, don't get worried about going into and out of your anaerobic zone at times, because by doing so you will increase your level of cardiovascular stamina and endurance, strengthening your heart muscle while still burning calories.