Figure 2
Age-specific percentile curves for each physical fitness test, by sex

Figure 2 consists of ten age-specific percentile curves for five different fitness tests including grip strength in kilograms, $\dot{V}{O}_{2max}$ in millilitres per kilogram per minutes, flexibility in cm of the sit-and-reach test, jumping height in centimetres and jumping power in kilowatts. For each of the five fitness tests, there is a graph for males and females. There are three curves displayed on each graph, one at the 90^th percentile, one at the 50^th percentile and one at the 10^th percentile. The x-axis along the bottom denotes age in years from 3 to 69.

All fitness levels, with the exception of flexibility, were greater among males compared to females.

Grip strength increased in males between the ages of 6 and 20 years and then declined with age. Grip strength increased in females between the ages of 6 and 19 and then declined with age.

Cardiorespiratory fitness declined steadily with age beginning at 8 years in both males and females, with a more pronounced decline evident in females between 8 and 18 years.

Flexibility remained relatively stable with age for both males and females.

Among males, jumping height increased between ages 8 and 20, followed by a decline in performance with age. Jumping height increased in females between the ages of 8 and 13 years, followed by a decline in performance with age.

Among males, jumping power increased between the ages of 8 and 20, followed by a decline with age. Jumping power increased noticeably in females between the ages of 8 and 13 years, but this was followed by incremental increases until about 18 years, and then a decline with age from that point onwards.