Proponents of blood type diets believe individual blood types are indicators of a person's susceptibility to specific illnesses and their responses to the foods they eat. In addition, each blood type requires a different style of exercise to attain and maintain a healthy weight. The theory of the Blood Type Diet is the brainchild of author Dr. Peter D'Adamo who has written two best-selling books on the topic. On his website, Eat Right For Your Type, D'Adamo explains his theory that individuals with type O blood are predisposed to conditions such as ulcers, underactive thyroid gland and a sensitive stress response. Exercise specifically for individuals with type O blood addresses many of these predispositions. Discuss using the Blood Type Diet with your doctor before you start.

D'Adamo explains that individuals with type O blood derive the most benefit from exercise that is high-intensity, rather than low-intensity. Because type O individuals are generally hard working and have intense personalities, according to D'Adamo, they are usually active anyway. Type O's, according to the Health Care Ministry International website, tend to be physically strong but also have problems regulating their energy levels. Increasing metabolic rate through exercise is thought to help type O's increase both metabolism and energy.

To continue to stoke their metabolism and maintain energy levels, D'Adamo explains that type O's need to engage in exercise for at least 30 to 45 minutes. Type O's tend to have high stress levels, according to Health Care Ministry International. Long periods of exercise are generally more aerobic and the National Heart, Lung and Blood Institute explains that any activity that lasts for more than 30 minutes can decrease your risk of cardiovascular disease. Individuals who are type O are prone to conditions such as hypertension and high cholesterol, conditions that can lead to cardiovascular disease, D'Adamo believes.

For optimum weight control, stress control and energizing effects, D'Adamo recommends that type O individuals exercise at least four days a week. He adds that if you are a typical type O, you may become bored with the same type of exercise, so consider several different kinds of exercise that you enjoy and enjoy variety. Regular physical activity can also improve the quality of your sleep, decrease the risk of constipation and handle stress better. These conditions are all characteristic of a type O blood type personality.

The Blood Type Diet remains controversial and does not have scientific support for the claims that produce the eating and activity recommendations of this plan. Santa Clara University explains that because each blood type has specific dietary limitations, such as the recommendation that type O's avoid all dairy products, the main concern is nutritional deficiencies. Each of the blood types in the blood type diet plan has its own restrictions, but none of the specific types meet the dietary guidelines of the U.S. Food and Drug Administration.