Running pace is one of the primary measures of running intensity, however, variations in grade and surface limit quantifying intensity solely based on pace. With the advent of wearable running power meters, runners can assess the external work stimulus inclusive of pace, grade, and surface.
PURPOSE: To assess reliability, a running power meter was evaluated based on two trials of submaximal running on three different surfaces.
METHODS: Eight collegiate cross country runners (male n=4, age=21.25±0.50 yrs, weight=63.45±9.73 kg, height=178.5±10.82 cm; female n=4, age=20±1.41 yrs, weight=56.45±4.95 kg, height=169.5±7.97 cm) participated in two trials of submaximal running at 85% of lactate threshold (LT) on each of three different surfaces: treadmill, grass, and track. All subjects completed a a VO2max and LT running test. For this investigation, sub-maximal running speed/pace was determined from the maximal effort / LT test. During subsequent submaximal running trials, ventilatory and metabolic measures and heart rate (HR) were collected with a portable breath by breath analyzer (COSMED K4B2) and HR monitor (Polar). For the track and grass submaximal running, the runners were paced by a cyclist maintaining a constant speed using a speedometer. Intraclass correlations were run between trials 1 and 2 on all surfaces including treadmill, track and grass.
RESULTS: VO2, HR, and running power were all reliable between trials 1 and 2 on the 3 different surfaces (VO2: rtreadmill= 0.980, rgrass= 0.876, rtrack= 0.977; HR: rtreadmill= 0.938, rgrass= 0.978, rtrack= 0.981; Power1: rtreadmill= 0.995, rgrass= 0.999, rtrack= 1.00; Power2: rtreadmill= 1.00, rgrass= 1.00, rtrack= 1.00)
CONCLUSIONS: The results support that the Stryd running power meter can reliably measure power of submaximal running on three different surfaces including treadmill, grass, and track.