Validity and test-retest reliability of the 1080 quantum system for bench press exercise

Boehringer, S and Whyte, DG. Validity and test-retest reliability of the 1080 Quantum System for bench press exercise. J Strength Cond Res 33(12): 3242–3251, 2019—This study assessed the validity and reliability of the 1080 Quantum (1080Q) during the bench press exercise. Twenty-seven resistance-trained men (28 ± 4 years; body mass 88.9 ± 12.8 kg; 1 repetition maximum [1RM] bench press 94.8 ± 10.7 kg) completed 2 test-retest sessions, separated by 1 week. In each session, subjects performed single repetitions at 30, 40, 50, 60, 70, and 80% of their bench press 1RM. Mean velocity (Vmean), peak velocity (Vpeak), mean force (Fmean), peak force (Fpeak), mean power (Pmean), and peak power (Ppeak) were simultaneously assessed using the 1080Q Synchro and a linear position transducer (GymAware; Kinetic Performance Technology, Canberra, Australia). The overall performance of the 1080Q was both valid (r = 0.94–1.00) and reliable (coefficient of variation [CV] = 1.7–8.0%, intraclass correlation coefficient [ICC] = 0.90–1.00) for all measures, although both fixed and systematic biases were present. When assessed at each of the relative loads, the 1080Q remained valid for all measures apart from Fmean at 30% 1RM (r = 0.78) and Fpeak at 70 (r = 0.81) and 80% (r = 0.57) 1RM. The 1080Q also demonstrated excellent reliability at all relative loads apart from the heaviest, where Vmean (CV = 11.0%, ICC = 0.69), Pmean (CV = 11.4%, ICC = 0.65), and Ppeak (CV = 10.2%, ICC = 0.79) reliability was reduced. These data indicate that athletes and strength and conditioning coaches can confidently use the 1080Q to monitor training progression; however, caution should be taken when assessing performance measures at the either end of the load spectrum.