The Spark Activity Tracker uses a 3-axis accelerometer to measure your patterns of motion. This allows the tracker to determine your total steps, activity time and speed, which is then used to calculate distance and calories burned.
The Spark will track the following activities and automatically sync them to your online Fitness Tracker:
All-Day Activities like running up the stairs, walking through the grocery store and playing tag with your kids
Since the Spark can determine the different types of activities you are doing, it will display your time, distance, and calories burned based on your personal profile. Movement such has yard work will likely come up as a "general workout" and then you will need to reclassify it to get a more accurate reading.
Hope that helps. You can find more FAQ's here that might also help. www.sparkactivitytracker.com/spark-activit