Activity goals

The Withings watch (Steel HR Sport) undercounts steps for daily activities like vacuuming, doing laundry, and shopping at the grocery store, even though they require walking, lifting, twisting, etc. It seems to count strides, not steps, so its counts need to be doubled for these activities. However, when I hike outdoors and manually start a "sport session,” the counts seems to be pretty good. Hiking outdoors generates more arm swing and so steps are counted more accurately. In the 3 months that I have worn the watch I have clocked over 10,000 steps in a day only 3 times. Today was one of those days. I did some chores during the day and took a 1.5 hour hike outdoors in the evening. I know from the fatigue I feel that I earned every one of those steps!

I have little interest in counting active calories, because they are so clearly connected to movement/steps that there is little new information provided. Dozens of trackers and smartwatches have been tested. Each uses “proprietary” formulas based on steps, gender, age, height, and weight. They typically do not use heart rate, respiration, or body temperature, which would increase accuracy. In general, the studies show that they are not all that accurate compared to a scientific/medical evaluation of VO2 max or calorie burn in a metabolic chamber, but they are pretty consistent over time and activities. That is, you can use them to know days when you are burning more calories, but you can’t use them to determine that you have burned exactly 200 calories.

Once again, however, curiosity led me to make comparisons of my own. After today’s big achievement, I looked at the calorie counts for the last 5 days. The chart below shows the Withings watch compared to the Oura ring. As with other comparisons I have made, they are closest on days that involve a hike or walk outdoors (marked with an asterisk), with Withings under-estimating steps/calories when activities do not involve lots of arm swing.