Purpose: To describe muscular fitness (MF) levels and percentile benchmarks among U.S. children and adolescents aged 6–15 years old across sociodemographic, physiological, and behavioral subgroups. Methods: Data were from the 2012 NHANES National Youth Fitness Survey (NNYFS). Four strength tests consisting of the plank, knee extension, modified pull-up, and handgrip, were analyzed by age, sex, race/ethnicity, income, BMI category, cardiorespiratory fitness (CRF), and physical activity (PA) among 1,234 participants (51% male) using SAS SURVEY procedures. Results: Mean ± SEM scores were 69.6 ± 1.8 s (plank), 56.6 ± 4.2 lb (left) and 59.2 ± 4.3 lb (right) knee extension, 5.5 ± 0.3 pull-ups, and 21.2 ± 0.3 kg handgrip strength. Male adolescents (12–15 y) scored higher than females on all tests (p 127 s (90th), knee extension from ~33 lb to > 100 lb, handgrip from 14 to > 33 kg, and pull-ups from 0 to 13 reps. Conclusions: These nationally representative MF benchmarks for U.S. youth highlight subgroup disparities and support the need for continued surveillance to guide youth strength promotion initiatives.
McDonough et al. (Wed,) studied this question.