Validating the Adidas miCoach and Nike+ Sport Kit for estimating pace, distance, and energy expenditure during over-ground exercise

There is currently no known published research validating the Adidas miCoach or Nike+ Sport Kit personal training systems for outdoor, over-ground walking and running. To validate these devices for estimating pace (min.km-1), distance (km) and energy expenditure (EE) (kcal·min-1) during outdoor over-ground walking and running for two different sensor configurations, 6 male and 8 female participants with moderate endurance training (Mean ± SE Age: 28.21 ± 2.27 y; Body Mass: 60.93 ± 2.97 kg; Height: 167.43 ± 2.09 cm; Percent Body Fat: 14.93 ± 1.94% (N=16); and VO2max: 54.44 ± 1.47 mL·kg-1·min -1) completed this study. The protocol consisted of walking at 53.6, 80.4 and 107.2 m·min-1 and running at 134.0, 160.8, 187.6 and 214.0 m·min-1 on an outdoor, 400 meter track, while wearing a portable metabolic measurement unit (COSMED K4b2). Each sensor was attached on the right (miCoach) and left (Nike+) shoelaces (LC), as well as the midsole (MC) of the shoe. Estimated pace, distance and EE were compared to values determined by criterion methods (AC). Data were analyzed using a MANOVA (pace, distance) or MANCOVA with repeated measures (energy expenditure) to evaluate significant differences. For the miCoach, each subsequent stage elicited a significant change in estimated pace for both the LC and MC (p≤0.001) except between 53.6 and 80.4 m·min -1, and 107.2 and 134.0 m·min-1 at the MC. The miCoach LC and MC also demonstrated a significant change for distance (p=0.019) and EE (p=0.032) with each subsequent speed. For the Nike+, each subsequent stage elicited a significant change in estimated values for pace (p=0.001), distance (p\u3c 0.001), and EE (p\u3c0.001). The miCoach LC and MC pace were significantly different from each other at 80.4 m·min-1\u3e (p=0.021). There were no other significant differences seen between miCoach LC and MC, or between Nike+ LC and MC for pace; likewise, there were no significant differences between the miCoach LC and MC or Nike+ LC and MC for distance. The miCoach LC and MC EE were significantly different from each other at walking speeds of 53.6 and 80.4 m·min-1\u3e (p≤0.012). There were no other significant differences seen between the miCoach LC and MC, or between the Nike+ LC and MC for EE. For practical purposes, miCoach seems to be useful; however, the Nike+ seems to fall short of the manufacturers\u27 claims. The inability of both the miCoach and Nike+ to correctly estimate pace, distance and EE across the entire range of speeds indicates that these do not appear to be valid assessment instruments for outdoor research purposes