Tori Kaster

Date of Award

January 2019

Document Type


Degree Name

Master of Science (MS)


Kinesiology & Public Health Education

First Advisor

Grant Tomkinson


Objective: To estimate national and international temporal trends in the sit-ups

performance of children and adolescents, and to examine relationships between trends in sit-ups performance and trends in health-related and sociodemographic indicators. Methods: Data were obtained in three ways: (a) through a systematic electronic database search of studies reporting on temporal trends in the handgrip strength of apparently healthy 9–17 year-olds, (b) by pearling reference lists, topical systematic reviews and personal libraries, and (c) by examining large country-level fitness datasets suitable to temporal trends analysis. Sample-weighted temporal trends (expressed as percent and standardized trends) were estimated at the country-sex-age level using best-fitting regression models relating the year of testing to mean sit-ups performance. International and national trends were estimated by post-stratified population-weighted mean changes standardized to the year 2000. Pearson’s correlations were used to quantify relationships between linear trends in sit-ups performance and linear trends in health-related and sociodemographic indicators.

Results: Trend data from 27 studies/datasets representing 9,939,289 children and adolescents representing 31 countries (25 high-, 5 upper-middle-, and 1 low-income countries) between 1964 and 2017 collectively showed a large improvement in mean sit- ups performance of 38.4% (95%CI: 36.8 to 40.0) or 7.1% per decade (95%CI: 6.8 to 7.4). Large international improvements were experienced by all age and sex groups, with the rate of improvement slowing from 1964 to 2000, stabilizing near zero until 2010, before declining thereafter. Trends differed in magnitude and direction between countries, with most experiencing improvements. Trends in vigorous physical activity levels were a strong positive correlate of trends in sit-ups performance.

Conclusions: There has been a large international improvement in children’s sit-ups performance since 1967, which has progressively diminished in magnitude over time. Sit- ups data are needed from children in low-income and middle-income countries in order to better monitor national and international trends in muscular fitness.

Available for download on Friday, September 03, 2021