Lab tests calibrate energy and ventilation rates to heart rate for trial assessment.

E-bikes require less energy than regular bike (24%) and walk (64%) for same bout.

E-bikes require moderate (level, downhill) and vigorous (uphill) physical activity.

E-bikes elicit higher enjoyment scores, less exertion, and lower need to shower.

The paper is here:  http://www.sciencedirect.com/science/article/pii/S2214140516303930