Interesting to compare two recent rides by the same person, one on an e-MTB (the Kinesis Rise Pro) and one on a regular 29er mountain bike, to see the difference.
This was by no means a controlled scientific experiment (we might have a go at doing this in a more scientific way in future), but it gives an interesting insight in terms of the calories burned and vertical feet.
I was wearing a heart rate monitor so the energy required should be reasonably accurate. What is revealing is that on rides of very similar durations and energy levels consumed, the e-bike allowed me to do almost double the vertical.
I was able to climb 2.3 feet per calorie burned on the eMTB compared to 1.1 feet per calorie on the normal (much lighter) mountain bike. This was in spite of the fact that the second ride was a lot drier – and I had plenty of battery left at the end, having ridden mainly in "River" and "Breeze" modes.
So, to answer the question, while e-biking might be cheating, that doesn’t mean it isn’t great exercise – and you know what twice as much "up" means…