Does a Faster E-Bike Commute Leave You with Less Exercise?

You're considering an e-bike for a trip you already make, perhaps to work, the store, or a friend's house. Then comes the question: if the motor helps, how much exercise would the ride count for? You might compare it with pedaling a regular bike along the same route. Or you might be thinking about a journey you would otherwise make by car. Before putting a number on the ride, it helps to decide which of those questions you want answered.

Effort and journey time are separate parts of that comparison. In an experiment involving eight healthy adults aged 23–54, assisted journeys had lower median relative intensity and shorter median duration than conventional journeys on the tested flat and hilly routes. Riders used maximal electrical assistance and chose their own commuting effort. On the hilly route, median intensity was 50% of measured maximum oxygen uptake with assistance, versus 60% without it; median journey times were 18.8 and 26.3 minutes, respectively. Those figures describe two tested bike configurations, not an isolated motor effect. The route was matched, but bike mass, chosen pace and journey duration were not identical. The medians were descriptive comparisons, without statistical tests of the differences.¹

A less intense ride can nevertheless spend a large share of its time above an activity threshold. About 95% of riding time qualified as moderate-to-vigorous physical activity in both modes under this study's definition: oxygen use at least three times each person's measured resting level, or three measured metabolic equivalents (METs). That ratio to rest differs from the percentage of maximum oxygen uptake used above. The two measures describe intensity against different reference points.¹

The similar percentages did not mean similar accumulated minutes. Across the tested routes, pooled median qualifying time was 19.0 minutes for assisted journeys and 23.9 minutes for conventional journeys. The high qualifying share therefore coexisted with fewer qualifying minutes in the assisted trips. Neither measure was a test of health benefit.¹

Daily travel adds a comparison that these assigned journeys could not supply. A net weekly activity estimate needs to specify which travel mode was displaced, how often and how far the person actually rode, and what other activity occurred over that period. More frequent or longer rides could offset fewer qualifying minutes per trip, but this one-day experiment did not follow travel replacement or later riding. The effect on weekly activity remained unmeasured.¹

When considering how an e-bike would fit into your activity, separate the ride you are comparing from the weekly routine you are planning. For the ride, specify the route and the alternative bicycle. For the week, specify the journeys you would replace and how often you expect to ride. This gives you a specific travel question to consider alongside the rest of your routine.