Personal factors that you might want to consider when choosing an exercise schedule and the research. First, an important definition. There are 11 components to fitness. Five health-related and six skill-related components together make up fitness. The five health-related components of physical fitness are cardiovascular endurance, muscular endurance, muscular strength, flexibility and body composition. The six skill-related components of physical fitness … Continue reading How much exercise do I need to do? The science.