There is no single exercise program for everybody. All exercise programs should be custom fit to the individual. You should appreciate and respect others' training programs, but you must follow one that fits you. In group exercise programs, individuals are grouped together, follow the workout program and expect to do well. The instructor leads the group through the same intensity, duration and frequency of exercises. Some will do well and others will not. There are always a few in the class that lose weight. To them the instructor is brilliant. Those participants that fail to accomplish their goals think the class is a failure. They may even lose motivation and stop exercising altogether. It isn't the instructor that has failed or has the participant failed, he or she just hasn't individualized their workout. To honor your individualized workout base your workout on heart rate and heart rate zones.

Heart Rate Zones

Each zone is unique. What happens physiologically changes between them, such as fuels consumed, your feeling while in the zone, the amount of time you can spend in each zone and the training effect that results.

You can't get the benefit of one zone while training in another zone. You can only get the benefit of the specific zone you are experiencing. All zones are part of a wellness continuum from health to performance.

Aerobic vs. Anaerobic

The most obvious distinction between aerobic and anaerobic activity is the different kinds of fuels they rely on. Aerobic workout utilizes fat (fatty acids) as a source of energy, while anaerobic activity utilizes sugars (glucose) as a source of energy.

Aerobic is the chemical state when the body is burning fats. It helps you burn unwanted fat and improve many health parameters. (IE: blood pressure, cholesterol levels, and blood sugar) The aerobic process improves the hearts condition as well as blood circulation. It helps the body regulate fats and the hormonal system. The anaerobic process cannot provide any of these benefits. Exercising well below your AT develops your aerobic capacity.

Anaerobic is the chemical state when the body is burning sugars. When your body is burning sugars it is not burning fats. Frequently it is storing fats.

Anaerobic Threshold

Physiologists use Anaerobic Threshold to describe the crossover point where your body shifts from primarily burning fats as a fuel source to burning sugars as a fuel source.

Many zone-based fitness methods identify Anaerobic Threshold (AT) as a percentage of maximum heart rate (MHR), but estimates of where AT occurs can range a great deal. Some experts suggest that AT occurs 80 -- 85 percent of MHR; others say 85 -- 90 percent MHR. Since most cardiovascular training emphasizes staying within the zone your heart is working aerobically, knowing your actual AT will make your training more precise. Exercising in the area of, or just below your AT increases your exercise endurance, improves cardiovascular fitness and increases post exercise caloric expenditure.

Exercising at or above your AT boosts endurance and exercise performance. It can also increase your aerobic range and develops your ability to tolerate higher levels of lactate acid (the burning sensation) in your blood.

The simple question is then, how do I determine whether my workouts are aerobic or anaerobic?

Simple Assessments

Best Method
The best method to target your AT is to undergo a metabolic assessment. This assessment analyzes the oxygen you consume and carbon dioxide you expire under varying levels of exercise, usually on a treadmill or on a stationary bike. The point at which the oxygen you consume equals the carbon dioxide you exhale marks your AT.

Fair Method
In the absence of any testing, you can estimate your AT by using the following formula.

1. Subtract your age from 180.
2. Adjust this number accordingly.
   • Subtract 10 if you have not exercised in more than one year.
   • If you have been exercising for up to two years, at least four times a week, subtract zero.
   • Add 5 if you have been exercising for more than two years, at least four times a week.
   • If you are a competitive athlete, add 10.

Zone 1

The kick off zone to those new to exercising.

Zone 1 builds a healthier heart. Your heart muscle gets stronger and more efficient. Not a lot of total calories are burned here, but those that are come primarily from your body's fat stores.

Zone 2

The benefits you get from training in this zone are increased skeletal muscle mass and decreased body fat. You're training your body to metabolize fat, which includes fat mobilization, transportation and utilization.

Also in this zone you will realize improved aerobic function. As you spend more time in this zone you will increase your capacity to burn fat by increasing the number of mitochondria -- the energy factories in each muscle cell. In other words, this zone allows you open your fat cells and let the fat out of them, while turning on the demand for fat by your muscles.

Zone 3

This zone will give you the biggest fitness benefits in the least amount of time. You'll maximize your efforts because you are burning many calories in the form of fat and carbs. Simultaneously, your body is consuming a lot of oxygen and your cardiopulmonary system improves drastically. Finally you build resistance to fatigue and increase your endurance.

Other benefits arising out of this zone is mood improvements, reduction of anxiety, and improved appetite control. And these benefits will last for hours after your workout.

Zone 4

This zone leads to improved sports and fitness performance. If you want to get really fit, you need to spend some time in this zone. Somewhere in this zone most individuals pass from aerobic to anaerobic exercise.

Zone 4 is high intensity training. It isn't an easy zone to stay in. It has high heart rate numbers and is a challenge to stay in this zone for more than 60 minutes.

Zone 5

This is where you face your maximum heart rate. This zone is only for competitive athletes. Your breathing is so hard it becomes labored. Athletes suffer in pain as they try to deliver maximum metabolic demands from the muscles. It is not a sustainable training zone because your heart can't and won't work at or near its maximum intensity long. Stay too long here and you'll reach complete exhaustion.

Bob Townsend is a veteran triathlete, a two time Ironman finisher with 10 years of experience and nearly 30 years of running and cycling experience. He is a certified triathlon coach by USA Triathlon and a certified cycling coach by USA Cycling. Bob also holds certifications from the National Strength and Conditioning Association as a Certified Strength & Conditioning Specialist and a Personal Training certification from American College of Sports Medicine.