NAFC Fitness Assessment Practice Exam

Cardiovascular endurance refers to the ability of the heart and lungs to supply oxygen to the muscles during sustained physical activity. Age is a significant factor influencing cardiovascular endurance because, physiologically, as individuals age, there are typically declines in maximal heart rate, cardiac output, and overall aerobic capacity. These changes can affect how efficiently the body can utilize oxygen during exercise.

It's observed that younger individuals generally have a higher peak oxygen consumption and recovery rates, which contributes to better endurance performance. While fitness levels can be improved regardless of age through training, the natural aging process can lead to decreased cardiovascular efficiency.

The other factors, such as flexibility levels, muscle size, and body composition, certainly play roles in overall fitness but don't directly correlate to the efficiency and capacity of the cardiovascular system in the same way that age does. Flexibility influences how the body moves and may prevent injury, muscle size contributes to strength rather than endurance, and body composition reflects the proportion of fat to lean mass but does not directly measure cardiovascular capacity. Thus, age stands out as a key influencing factor on cardiovascular endurance.