Validity and Test-Retest Reliability of the 1080 Quantum System for Bench Press Exercise

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 (V-mean), peak velocity (V-peak), mean force (F-mean), peak force (F-peak), mean power (P-mean), and peak power (P-peak) 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 F-mean at 30% 1RM (r = 0.78) and F-peak 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 V-mean (CV = 11.0%, ICC = 0.69), P-mean (CV = 11.4%, ICC = 0.65), and P-peak (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.