The word exercise can mean the following:

• A setting in action or practicing.
• Any activity designed to develop or hone a skill or ability.
• Physical exercise

Physical exercise

Physical exercise is activity performed in order to develop or maintain physical fitness and overall health. Frequent and regular exercise is an important component in the prevention of some of the diseases of affluence such as cancer, heart disease, diabetes and obesity.

Exercises are generally grouped into three types depending on the overall effect they have on the human body:

• Flexibility exercises such as stretching improve the range of motion of muscles and joints.
• Aerobic exercises such as walking and running focus on increasing cardiovascular endurance.
• Anaerobic exercises such as weightlifting increase short-term muscle strength.

Exercise can be an important part of physical therapy, weight loss or sports performance.

Exercise can be fun, but be sure to do what you like and eat enough calories, so when you do exercise you are building up muscles, not breaking them down for fuel. Carbohydrates are muscle-sparing; and if you don't get enough calories overall, you burn muscles up with the fat to make up the deficit.

Exercise benefits

Frequent and regular exercise has been shown to help prevent or to improve major illnesses such as high blood pressure, obesity, heart disease, diabetes, insomnia, cancer [1] (http://www.wcrf.org/) and depression, among others.

Common myths

Many common myths have arisen surrounding exercise, some of which have a basis in reality, and some which are completely false.

• No Pain No Gain.

This is generally false. Depending upon the type of exercise you are engaged in and the underlying cause of the pain, actual pain, as opposed to discomfort, is generally a sign that you are causing more harm than good (eg tearing a muscle). It is common to experience sore muscles the day after a workout following the start of an exercise program. This is due to the many microscopic 'micro-tears' in the muscle and possibly metabolite build-up, and is known either as Post Exercise Muscle Stiffness or Delayed Onset Muscle Soreness (DOMS). You should NOT feel pain during or immediately after a workout. Pain at these times can indicate a serious condition that requires immediate medical attention. It is uncommon to experience pain the next day after you have been engaged in a program for a month or more. If this is the case you should seek medical advice.

• Only overweight people need a physical before beginning an exercise program.

Absolutely false. Only a physician can determine your ability to engage in an exercise program. Apparently healthy people can still have unknown medical conditions, such as a heart murmur, that can cause severe injury or death not only to themselves, but also to others that are dependent upon them, such as someone they are spotting.

List of activities used as physical exercises

• aerobics
• calisthenics
• cycling
• dancing
• pilates
• rowing
• running
• sexercises
• sport
• stretching
• walking
• warming up
• weight training
• yoga
• dancing

List of classes of physical exercise

• Aerobic exercise
• Anaerobic exercise
• Endurance exercise
• High-density exercise
• High-intensity interval training (HIIT)
• Resistance training

Some activities can fall into more than one class of exercise. For instance: cycling can be used for endurance or high-intensity interval training; weightlifting is resistance training and can be high-density exercise with certain workout designs.

Breathing

Active exhalation during physical exercise helps the body to increase its maximum lung capacity, and oxygen uptake. This results in greater cardiac efficiency, since the heart has to do less work to oxygenate the muscles, and there is also increased muscular efficiency through greater blood flow. Consciously breathing deeply during aerobic exercise helps this development of the heart lung efficiency.

During breathing, males mostly use the intercostal muscles in the rib cage, females mostly use abdominal muscles. In strenuous exercise, it is likely that these differences diminish.