Cardio
Cardio fitness training is exercise that raises your heart rate enough to burn fat and to challenge your heart and lungs. You can tell is you are exercising at a cardio level by checking these simple signs: Are you breathing hard and sweating? Can you still carry on a conversation with another person while continuing your activity? If your answer to these questions is yes, you are involved in cardio exercise. If you want to get more precise, invest in a heart rate monitor; it will give you the cardio exercise range for your age, gender and weight.

• Low impact cardio: Low impact cardio exercise raises your heart rate without abusing your joints. Using the elliptical machine in the gym, biking, and swimming are all examples of low impact cardio exercise.
• High impact cardio: High impact exercise involves a good deal of pounding. One of the benefits of high impact cardio exercise is that it promotes the preservation of and rebuilding of bone density. Jumping rope, running, jogging, and performing jumping jacks are all examples of high impact exercise. 

Strength training
Strength training involves toning exercises, lifting weights, using resistance bands, and any other form of muscles building exercise.  This type of fitness training is bound to increase your muscle mass, which in turn increases your metabolism, helping your body to burn more fat.

• Resistance training: Resistance training is a form of strength training using resistance bands or weight machines designated to provide resistance.
• Weight lifting: You can use hand weights, dumbbells, and weight machines to increase your muscle mass as a part of your strength training plan.
• Calisthenics: Push-ups, sit-ups, leg lifts, pull-ups and squats-all of these exercises work to tone the muscles and increase muscle mass. 

Stretching
This is a type of fitness training many people ignore. If you want to stay fit, protect your self against injuries, and remain flexible, you need to spend time stretching your muscles, especially before and after cardio exercise or strength training. You can learn stretches specific to your most used muscles groups from a physical therapist or personal trainer, or you can attend yoga classes to learn how to stretch properly.

Combination sports
Many sports and fitness activities are combinations of all three of the categories listed above. Yoga is perhaps the best combination of strength training and stretching; cross country skiing is perhaps one of the best examples of a combination of cardio and strength training.

Try to work all of these types of fitness training into your life. By cross training, you'll work your muscles equally and become a fit, flexible, strong athlete.