Test-Retest Reliability of Selected LifeCircuit Machines

ABSTRACT This study was done to (a) determine the test-retest reliability of selected LifeCircuit strength training machines and (b) examine the accuracy of the set-up test as a percentage of 1-RM. Fifty eight subjects (28 M, 30 F) with at least 3 months strength training experience completed the study. Two testing sessions were given 3 to 7 days apart on 5 LifeCircuit weight training machines. On each day, subjects performed the set-up test (a modified version of the 1-RM test) and a standard 1-RM test on each machine. Reliability of the set-up test, done according to the manufacturer's protocol, was acceptable for men but only moderate for women. When the set-up test was converted to %1-RM, the mean values for the 5 machines ranged from 40 to 67% for men and 45 to 56% for women. While these average values suggest the machines are quite accurate in calculating %1-RM, the range of scores was very large (20–101% of 1-RM). Thus the appropriate training intensity could be markedly over- or underestimated. Given these variable results, it is recommended that instructors and trainers use caution when prescribing training programs.