As of the latest firmware (that is, just this week,) Wahoo apparently now discards power data entirely in their calorie calculations. With the Bolt, if my avg. heartrate is less than 65% of max, kcal expended is derived by using an algorithm based on basal metabolic rate:
BMR = 66 + (13.7 * weightKg) + (5 * heightCm) - (6.8 * ageYears)
As my chest strap HRM is a few years old, it can sometimes take about a mile or so to connect with the head unit, so I get absolutely nothing for the first mile-- the kcal screen will just sit on zero.
So combining HR data with dumb algorithms results in me burning absurdly low amounts of calories-- yesterday was 34 miles w/ ~1,000ft of vertical @ 16.8mph: 1,168kJ, 845kcal, or 25kcal.mi.
Today was an even more leisurely 22.5 miles w/ 659ft @ 15.9mph: 723kj, 587kcal, or 26kcal/mi. I climbed less, went slower, and burned more per mile.
So this is great for people without PMs, and not so great for people with. Either that or I've become really, really efficient. I'm wondering what the Bolt does if I just leave the HRM at home.
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