Results of Consumer Based Physical Activity Monitor Study!
Many new consumer-based activity monitors have been released into the market but it is important to determine how accurate they are for assessing energy expenditure. Aerobic exercise and resistance training are the two most common exercise types. Rather than physical activity, sedentary activity (e.g., reading, watching TV, typing) accounts for the majority of the waking time. Thus, the purpose of the recent study was to validate the accuracy of various, consumer-based activity monitors against criterion estimates from a portable metabolic assessment system during aerobic exercise, resistance training, and sedentary activity. There is a unique design feature differentiates our recent study from other traditional validation studies and our past work. In this study, the participants were given the flexibility to choose the types and/or intensity in the three different behavior domains. For example, they can choose to read, type, watch videos, or listen to music during the sedentary activity period. They were free to select the speed of the treadmill in the aerobic exercise session and had the freedom to select the weights, sets, repetitions, and equipment for resistance exercise. The goal was to simulate a typical real-world scenario in which a person would be in a sedentary setting and then choose to go to complete a workout that included aerobic and resistance exercise. This context helps to evaluate the accuracy of the consumer-based activity monitors under typical conditions.
Over 50 healthy participants aged 18 to 65 volunteered in the study. Each of them performed 20 minutes of self-selected sedentary activities, 25 minutes of aerobic exercise on a treadmill, and 25 minutes resistance exercise, with 5 minutes rest between each activity. Each participant simultaneously wore Fitbit Flex, Polar Loop, Misfit Shine, Nike+Fuelband SE, Jawbone UP on the wrist, Actigraph GT3X+ on the waist, and BodyMedia Core on the left arm while being concurrently monitored with the Oxycon Mobile, a portable metabolic system (i.e., criterion). Four of the monitors produced error rates between 15 and 18% (BodyMedia Core, Fitbit Flex, Jawbone Up24 and Nike Fuelband SE). The two most accurate monitors were the BodyMedia Core followed by the Fitbit Flex in second. This was the same pattern observed in the previously published paper. The overall error rates were lower in the original study (~12-16% for the top monitors) but the BodyMedia Core and the Fitbit Flex were similarly ranked as the two most accurate monitors.
Over 50 healthy participants aged 18 to 65 volunteered in the study. Each of them performed 20 minutes of self-selected sedentary activities, 25 minutes of aerobic exercise on a treadmill, and 25 minutes resistance exercise, with 5 minutes rest between each activity. Each participant simultaneously wore Fitbit Flex, Polar Loop, Misfit Shine, Nike+Fuelband SE, Jawbone UP on the wrist, Actigraph GT3X+ on the waist, and BodyMedia Core on the left arm while being concurrently monitored with the Oxycon Mobile, a portable metabolic system (i.e., criterion). Four of the monitors produced error rates between 15 and 18% (BodyMedia Core, Fitbit Flex, Jawbone Up24 and Nike Fuelband SE). The two most accurate monitors were the BodyMedia Core followed by the Fitbit Flex in second. This was the same pattern observed in the previously published paper. The overall error rates were lower in the original study (~12-16% for the top monitors) but the BodyMedia Core and the Fitbit Flex were similarly ranked as the two most accurate monitors.
Examples of Different Consumer Activity Monitors
Our lab has continued to examine different consumer activity monitors with standardized protocols. The slide show below shows some of the monitors evaluated in various studies.