Fitness is defined as a condition of well being and health and, more importantly, the capacity to carry out certain parts of activities, jobs and sports. This definition may vary from one person to another, but the common factor that all fitness experts agree on is the fact that it involves the body’s ability to adapt to its environment. Fitness is usually achieved through appropriate nutrition, balanced exercise, adequate rest, and proper restorative sleep. The body achieves its fitness goals by dealing with the different changes that occur in it as it adapts to its surroundings.
Fitness also refers to a system’s ability to function within its environment. Fitness for an organism could be in the form of physiological functioning, behavioral functioning or ecological fitness. It could also be in the form of survival fitness or reproductive fitness. A physiological or metabolic definition of fitness can be seen as the way an organism responds to its environment.
An organism is considered fit when it has more than average fitness and is capable of surviving in its given environment. Fitness is also influenced by the genetic predisposition and heredity of an organism. Fitness is usually the outcome of the results of natural selection over the history of evolution and is also influenced by the effects of external factors like culture and stress. The theory of natural selection explains why some people are fit and others are not.
The definition of fitness has also been explained by the theory of positive selection. According to this theory, adaptation to local, seasonal and specific changes is favored in people who possess a higher level of fitness. Adaptation can be seen as the increase in strength, stamina and endurance as a result of genealogical history. People who have undergone extensive physical fitness training and have developed a well-balanced diet are considered fit. In addition, they have a high level of personal well-being. People who are not fit are those who have less than adequate fitness training and do not adapt well to local conditions and are often considered unhealthy.
The goal of most cardiovascular exercise programs is to increase overall fitness. Aerobic exercises improve oxygen consumption and enhance the capability of the heart to pump blood at a fast rate. The main benefit of cardiovascular exercise is that it improves the endurance capacity of the heart, reduces the risk of heart attacks and can prevent the development of heart diseases such as coronary artery disease and heart failure. Cardiovascular exercise is classified into two main groups: low intensity and high intensity. Both should be performed with the same purpose and the same outcome in mind – to achieve and maintain a healthy target heart rate zone.
Fitness differences between individuals can also be explained by the explanatory power of probabilistic anticipations. Probabilistic anticipations refers to the ability of an organism to adapt to differing environmental circumstances. Therefore, fitness improvements can be expected for those who are able to recognize the effects of environmental changes on their bodies and adapt accordingly.