Relationships between cardiovascular fitness level estimated in METS, and other health fitness markers for elementary and middle school children

The primary purpose of this study was to examine the relationship between a child's cardiovascular fitness level estimated in METS and other health fitness markers for elementary and middle school children. The secondary purpose consisted of identifying whether a specific MET threshold existed for identifying low physical fitness markers [i.e. cardiorespiratory endurance (METS), body mass index (BMI), muscular endurance (curl-ups), muscular strength (push-up), and flexibility (curl-up)]. The Cooper Institute FITNESSGRAMRTM data were collected for approximately 2230 elementary and middle school aged children (grades 4--8).;One-way analysis of variance (ANOVA) was used to determine the relationships amongst these variables for a total number of 1593 students (female, n=751; male, n=842) that had values for all variables of interest. The average age of participants was 13.08 +/- 1.55 years old. Males scored significantly higher than females in VO2max (+3.3 mL/kg/min), Max METS (+1 MET), curl-up (+10 curl-ups), push-up (+5 push-ups), (p<0.001 for all health markers). Females were significantly more flexible than males (+.5 inches) (p<0.001). No significant differences between gender for age and BMI were observed (p=0.957 and p=0.778, respectively).;There was a significant difference (p<0.001) in BMI and muscular strength scores between children classified with low aerobic fitness (<11.99 METS) and high aerobic fitness (≥11.99 METS), which existed regardless of sex. Muscular endurance scores were greater for the male children classified high aerobic fitness compared to low (p<0.001), there was no significant difference in curl-ups performed between high and low aerobic fit groups for females (p=0.102). BMI scores were less for those children classified high aerobic fitness compared to low, regardless of gender (p<0.001). There was no relationship between aerobic fitness and flexibility values for either gender (female, p=0.508; male, p=0.344).;There appears to be an association with estimated MET value and a higher BMI scores for children. The difference in BMI was greatest between children who ranked in the lowest MET quantile (<10.95 METS) and second lowest MET quantile (10.95--11.99 METS), regardless of gender. This finding suggests that improving aerobic fitness may significantly increase the likelihood of decreasing a child's BMI score. These findings support the need for further research regarding the association of aerobic fitness levels to more advanced health markers (blood pressure, blood glucose, triglycerides, etc.) since it now appears to be a modifier of fitness rather than a mere health marker for elementary and middle school aged children.