As a technologically challenged physician with a new Apple Watch, I was intrigued by Dr. Veerabhadrappa et al.’s recent article “Tracking Steps on Apple Watch at Different Walking Speeds” which concluded that the Apple Watch was an “extremely accurate device for measuring daily step counts for adults”. 1 It is a timely article as the popularity of “wearables” has soared. For weeks, I had marveled how much I must have been walking on rounds when logging 5–6 miles per day and even earned some congratulations from incredulous family members who did not believe that I exercised enough. However, I was embarrassed to realize that I had been logging thousands of steps (equivalent to a few miles a day) while simply sitting at the piano, practicing! My rate was about a mile per hour of piano practicing (Fig. 1). While the Apple Watch may be very good at capturing steps when walking, there can also be many “false positives.” It also reminded me about the need for caution when generalizing study results to draw wider conclusions.

Fig.1
figure 1

a–d Logging miles without taking a step: Apple Watch images before and after an hour of piano practicing

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