Fitness is generally considered as physical fitness of the human body. It is nothing but the ability of the human body to function with power and alertness without getting fatigue or lethargy. It is accompanied with ample energy to get involved in leisure activities and also to face physical stresses. Cardiorespiratory integrity, muscular strength and stability and general awareness are the hallmarks of physical fitness.

Physical fitness is generally measured in proportion to functional willingness. In other words, this is measured by periodic tests of strength, agility, coordination, flexibility and endurance. Many times, stress testing that ascertains the accommodation of the body to powerful, sustained physical stimuli can also be used to evaluate the physical fitness. Any individual who is able to face any kind of stressors whether physically or mentally, is assumed as 'fit'.

The physical fitness can be achieved by doing systematic exercise on regular basis. One who does moderate activities can maintain a level that can handle ordinary stress. If the fitness level is to be taken higher, it is quite important to include more intensive exercises, which can overload the physiological systems and therefore can promote the change.

The exercises, which require the total body's involvement will maintain and improve fitness more powerfully. For instance, swimming, vigorous dancing, cycling, jogging, running and brisk walking can help better to maintain one's body. Certain indoors and outdoors games like squash, lawn tennis, cricket burn more calories and hence are considered to be best for physical fitness.

Fitness is offered at many places in the market. Nowadays gyms and fitness centers are in bloom and doing extremely well. There are private clubs, studios and professionally organized clinics also offer fitness with attractive schemes and other offers.

Normal and healthy individual can start any of the exercise to remain fit. On the other hand, diseased or weak person should take an advice from an expert. There are certain rules for exercises that can keep you fit. The general rule for doing exercise is, an exercise is to be done only until the discomfort has begun. Here discomfort is breathing becoming labored, fatigue or sweating profusely.

Along with the exercises, proper nutrition and diet is also required for fitness. This is because it should meet the energy spent during exercises. In other words, when you do exercises, you burn the calories to get energy and these calories are to be replaced or re-supplied by taking proper nutrition in terms of diet. If the diet is inadequate, the fitness level drops.

Fitness is required for an individual to keep diseases away and if the disease already exists, then to keep it restricted. Now it is proved that generally longer periods of exercises reduces the risk of cardiac disease. However, the cardiac patient has to follow strict instruction given by the fitness guru. All the exercises done by a person having chronic disorders must be under strict medical supervision to avoid medical emergencies.

One can remain fit by doing proper exercises, having proper diet and following instructed regimen. This will help to maintain the health with mental and physical stability.