Childhood physical fitness relative to adult health outcomes coupled with scant longitudinal research indicates that tracking of fitness components throughout childhood/adolescence is imperative. The study examined the stability/tracking of 9 measures of fitness for boys and girls at 5 points throughout childhood/adolescence. Tracking coefficients between individual fitness measures at various age comparisons were calculated. Using a sample with recorded data at 4 time-points, tertiles (high, moderate, low) were calculated for each fitness measure for boys and girls. Stability of fitness measures was calculated. Boys outperformed girls on fitness measures at most time points. Significantly low to moderately high tracking coefficients for each fitness measure at all time points for boys (r = 0.21-0.79) and girls (r = 0.23-0.89) were found. Tertile ratings remained stable across the 4 time-points. Findings highlight the importance of developing healthy fitness behaviors early in life and the significance of intervention during adolescence in low-fit youth.