There was no correction for selection bias so you can’t make any assumptions.
For example; it’s likely that e-bike riders are older and have more spare time. How much would a regular cyclist exercise with the same spare time?
Aha! So, we're comparing mountain bikers and bike-sharers with e-bikes (which belong in the category of electrified city bikes). That alone should raise some informed eyebrows.
I can only going mountain biking on weekends, but it’s far from a low effort activity, I’d be willing to bet that I expend more energy and get more exercise than someone who trundles around the city on an e-bike.
So, since belonging to a group of bicycle use (leisure, sports, commute) is additive in the amount of exercise one receives, the e-bike group is automatically larger than the non-e-bike group.
How does this pass peer review?
- 365 e-bikers (2/3 of them from Antwerp and Zürich, only 20 from Barcelona, only 5 from London, only 18 from Örebro).
- 7212 cyclists.
- 1758 non-cyclists.
There are other things far more eyebrow-raising than the skewed sample.
> Categorical travel frequency data was converted into an average number of days per month.
> Trip distance was derived by selecting the fastest route returned by the Google Maps API
> Distances for multimodal trips were assigned to the main mode using the following hierarchy: public transport, car, e-bike, bicycle, walking
> Physical activity from active travel modes was almost the same in e-bikers and cyclists (1735 vs. 1656 MET min/wk., respectively)