Reliability of 1-repetition maximum estimation for upper and lower body muscular strength measurement in untrained middle aged type 2 diabetic patients.
OBJECTIVE
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 (ICC(2,1)=0.98-0.99) for all measurements with the highest for leg extension (ICC(2,1)=0.99). The SEM was lowest for lateral pull and leg extension exercises. Paired t-tests showed non-significant 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.
Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia (A Central University), New Delhi, India.
Unaise
U
Abdul-Hameed
Prateek
P
Rangra
Mohd Yakub
MY
Shareef
Mohd Ejaz
ME
Hussain
1-Repetition Maximum; Exercise; Prediction; Reliability; Type 2 Diabetes