Here’s a quick video from Hunter Allen of Peaks Coaching Group explaining why our indoor wattage is typically 20-30 watts lower than outdoor wattage. There are a number of factors contributing to this, but one major factor Hunter mentions is that many trainers give you consistent resistance across the entire pedal stroke, whereas outdoors you don’t get that resistance across the top and bottom.
Hunter also recommends using a separate set of power zones for indoor riding as opposed to outdoor, so your zones will be accurate. Watch the short video to get the whole message:
