Sometimes, no matter how hard you work out, you just don’t see the results you want.

But, knowing something as simple as your blood type could change the way you exercise.

“Each blood type is your own genetic blueprint,” said Dina Khader, a registered dietitian and integrative nutrition consultant based in Mt. Kisco, N.Y. “As a result, the foods you eat, the exercise you do would all have to be different. It makes perfect sense.”

There are four different types of blood – A, B, AB and O.  Your blood contains different types of antigens, which react with your immune system.

According to research by Dr. James D’Adamo, who wrote the original book “Eat Right for Your Type,” each blood type has evolved over the centuries and therefore, has different reactions to the food you eat and the exercise you do.

Type A

“We know blood type As, when they do a lot of intense exercise, they create more stress in their muscles,” Khader said. “So their muscles tighten up, and they build up much more lactic acid.  But it in turn increases cortisol levels for them, so they end up getting very fatigued, and they will eventually gain weight. Blood type As do better on more yoga, Tai Chi – those types of exercises.”

Type B

“B is for balance,” Khader said. “They do well with a little bit of yoga and stress reduction and deep-breathing exercise; but they also do very well with weight-lifting and cardio exercises.”

Type AB

Khader said people with type AB blood should combine aspects of both A and B exercise routines.

Type O

Khader said type Os thrive on intense exercise.

“The more intense the exercise, the better they feel – and the better results they get from their workouts,” she said. “They’ll end up losing more weight, burning fat, being energized. It’s a great endorphin release in the brain.”

Khader added that people who did a six-week program strictly adhering to a diet and exercise regimen tailored to their blood type, found that in addition to losing weight, they had more energy, didn’t get tired in the evening and were less stressed.

“The Blood Type Workout” kit lays out a program customized for you, based on your blood type.

For more information, go to bloodtypeworkout.com