Reliability in novel field-based fitness measurements and post-exercise scores from a physical fitness test battery in older adults

Introduction: Physical fitness is strongly associated with daily physical function, health, and longevity in older adults. Field-based tests may provide a reasonable alternative compared to advanced laboratory testing. Separating post-exercise test-scores from reactivity measurements requires sufficient test-retest reliability. Post-exercise test-scores with reliability-analyses of field-based fitness-tests in older adults are lacking. The present study aimed to examine the test-retest-reliability of some novel easily accommodated fitness-test-measurements and compare pre-test scores with post-exercise results in these tests along with other field-based fitness tests in older adults. Methods: Totally 1,407 community-dwelling-older-adults (69%-female), x̄=71.5±5.0 (65-84 years), performed twelve field-based-fitness-tests at pre-test-1, pre-test-2 and a post-test after an 8-week-exercise-period (twice weekly 1 hour of combined strength and aerobic training). T-tests, intra-class correlation, limits of agreement, standard error of measurement and coefficient of variance were performed between pre-1-and-pre-2-tests, and Repeated-Measures-ANOVA and partial eta squared effect size for post-exercise differences, for men and women in five-year age groups ranging from 65 to 84 years. Results: Between pre-1 and pre-2-tests a significant difference was noted in some of the novel fitness-test-measurements, but generally not e.g., in isometric trunk-flexion and step-up-height on either leg among all sex and age groups. In most of these novel fitness-test-measurements, no significant differences occurred between the two pre-tests. Examples of results from the pre-2-test to the post-test were: isometric-trunk-flexion-45°-endurance and isometric-trunk-extension-endurance improved significantly for both sexes in age groups 65-74 years. Women, but not men, improved the maximal step-up-height for both legs in most age-groups. The speed in the 50 sit-to-stand improved significantly for most age-groups in both sexes. Six-min-walk-distance improved significantly for most age-groups in women but among men only in 65-69 years. In the timed-up-and-go-test, significant improvements were seen for all age-groups in women and in men 70-79 years. No post-exercise improvements were generally observed for grip-strength or balance. Conclusions: In most of the novel fitness-test measures no significant difference was noted between the two pre-tests in the assessed sex and age groups. Results after the-8-week-exercise-period varied between sex and age-groups, with significant improvements in several of the twelve studied fitness-tests. These findings may be valuable for future projects utilizing easily accommodated physical fitness tests in older adults.