It looks to me like interval XP are based on duration but not intensity. I can do 5 minutes at 150 watts and get the same XP as 5 minutes at 225 watts or 5 minutes at 120 watts. As long as the time is based on an interval the intensity doesn’t seem to matter. Warm-ups, cool-downs and free ride are different. A 5 minute warm-up, cool-down or free ride doesn’t get as many XP as a 5-minute interval no matter what the intensity. My wish-list is for intensity, as a % of FTP, to factor into XP in intervals, warm-up, cool-down and free ride.
As far as I know XP are given based on distance only. Refer the Zwiftblog here on this:
When doing intervals, XP is awarded based on time or that’s the way it looks to me. I haven’t measured XP before and after an interval workout but when I’m doing an interval workout the only times my screen shows I’ve earned XP is at the conclusion of an interval. It’s approximately 10 XP/minute. When I complete a km the distance indicator turns orange like it does when I’m not doing intervals but it doesn’t show that XP was earned. 10 XP/minute is equivalent to 30 km/h if not doing intervals but when doing intervals you’re awarded the same XP on a climb that you would get on the flat even if the distance is much less. That’s why I think, when doing intervals or free ride, intensity should be factored in.
From Nigel’s link:
HOW DO I GET XP (POINTS)?
Points are added for every km (20 XP) or mile (30 XP) you ride. Points are added soon after each km or mile ticks over, unless you are in workout mode, where points are added after you complete a block. You will see a small alert to the right of your center console when points are added.
Sorry, America: since a kilometer is equal to .621 miles, you will accumulate XP slightly faster if you ride in metric units. (100km=2,000 XP, while the equivalent mileage, 62.13=1864 XP.)
You also get additional XP for the Large or Small Bonus power ups, and 10 points when you complete a KOM or sprint section.