Cardiovascular fitness is a special form of muscular endurance. It is the efficiency of the heart, lungs, and vascular system in delivering oxygen to the working muscle tissues so that prolonged physical work can be maintained. A person’s ability to deliver oxygen to the working muscles is affected by many physiological parameters, including heart rate, stroke volume, cardiac output, and maximal oxygen consumption.
Understanding the relationship between cardio respiratory endurance training and other categories of conditioning requires a review of changes that occur with increased aerobic, or anaerobic capacity. As aerobic/anaerobic capacity increases, general metabolism rises, muscle metabolism is enhanced, hemoglobin rises, buffers in the bloodstream increase, venous return is improved stroke volume is improved, and the blood bed becomes more able to adapt readily to varying demands. Each of these results of cardiovascular fitness/cardio respiratory conditioning will have a direct positive effect on muscular endurance, and an indirect effect on strength and flexibility.
To facilitate how a person does deliver oxygen to their working muscles, they need to train, or participate in activities that will build up the energy stores needed for their sport. This is referred to as metabolic training. Metabolic training is generally divided into two types: aerobic and anaerobic.
Aerobic Training: Aerobic training should be activities that are performed continuously for a minimum of 15 to 20 minutes at a level of 70% to 90% of maximal heart rate; no less than three times a week.
Anaerobic Training: Anaerobic training is shorter than aerobic training in duration (less than two minutes), in which oxygen is not a limiting factor in performance, and requires energy from anaerobic sources. These energy sources involve the utilization of phosphagen and lactic acid by the athlete’s body; and enables them to perform brief, near maximal muscular activity (<2 min). Events, or activity that lasts up to 30 seconds in length, rely almost exclusively on the phosphagen system.