INTER-MONITOR RELIABILITY OF A WRIST-WORN ACTIVITY MONITOR DURING RESISTANCE TRAINING EXERCISES

A.K. Fox1, A.H.K. Montoye, FACSM2, J.A. Steeves3, J.R. Mitrzyk2, C. Beach3, S.A. Conger1 1Boise State University, Boise, ID;2Alma College, Alma, MI; 3Maryville College, Maryville, TN Resistance training (RT) is an important part of the 2018 Physical Activity Guidelines for Americans. Until recently, methods to objectively assess RT exercises have been limited. The Atlas Wearables Wristband2 is an accelerometer-based activity monitor that is capable of identifying individual RT exercises and detecting the number of repetitions, but its inter-monitor reliability has not been investigated. PURPOSE: To determine the inter-monitor reliability of the Atlas Wearables Wristband2 monitor for exercise type identification and repetition counting and to assess the impact that various participant characteristics may have on the inter-monitor reliability. METHODS: Male and female participants (n=62) aged 18-55 yrs were recruited for this study. Each participant wore two Atlas monitors on the left wrist and performed 12 repetitions of 14 different resistance training (including dumbbell, machine, and body weight) exercises using self-selected weight. Inter-monitor reliability was assessed by calculating the percent agreement for each exercise type and for number of repetitions measured between both monitors. Sub-analyses were also completed for reliability by gender, RT experience, and height. Percent agreement and mean absolute percent error were calculated for each activity. Independent t-tests were conducted to assess subgroup comparisons. RESULTS: Overall, the inter-monitor reliability between the two monitors was 80.4±1.3% agreement for exercise type and 59.6±2.2% agreement for number of repetitions. Mean absolute percent errors for repetition counting were low (\u3c1.5 reps) for all 14 exercises. Overall, there were no significant differences in exercise type identification or repetition counting when the data were assessed by gender, RT experience, or height. CONCLUSION: The inter-monitor reliability of the Atlas Wearables Wristband2 was high for exercise type agreement. However, the agreement between monitors when measuring repetitions was slightly lower. The lack of differences in reliability by gender, RT experience, height is encouraging as it suggests similar device reliability across different populations