Reliability of 1-Repetition Maximum Estimation for Upper and Lower Body Muscular Strength Measurement in Untrained Middle Aged Type 2 Diabetic Patients

Purpose: the 1-repetition maximum (1-rm) test is the gold standard test for evaluating maximal dynamic strength of groups of muscles. however, safety of actual 1-rm testing is questionable in clinical situations such as type 2 diabetes (t2d), where an estimated 1-rm test is preferred. it is unclear if acceptable test retest reliability exists for the estimated 1-rm test in middle aged t2d patients. this study examined the reliability of the estimated 1-rm strength test in untrained middle aged t2d subjects. methods: twenty five untrained diabetic males (n=19) and females (n=6) aged 40.7+0.4 years participated in the study. participants undertook the first estimated 1-rm test for five exercises namely supine bench press, leg press, lateral pull, leg extension and seated biceps curls. a familiarisation session was provided three to five days before the first test. 1-rm was estimated for all participants by brzycki 1-rm prediction equation. another identical 1-rm estimation procedure occurred one week after first test. intraclass correlation coefficients (icc), paired t-test, standard error of measurement (sem), bland- altman plots, and estimation of 95% ci were used to assess reliability. results: test-retest reliability was excellent (icc2,1=0.98-0.99) for all measurements with the highest for leg extension (icc2,1=0.99). the sem was lowest for lateral pull and leg extension exercises. paired t-tests showed nonsignificant differences between the means of 2 sessions across three of five exercises. conclusions: the study findings suggest that estimation of 1-rm is reliable for upper and lower body muscular strength measurement in untrained middle aged t2d patients.