Yes, if you're riding it honestly hard. A Brigham Young University study found eMTB riders hit about 94 percent of the heart rate they reached riding the same trails on a regular mountain bike. That's real cardio, ride after ride. The bike is doing its job. The bigger problem is that your devices under-credit the work.
The BYU study put experienced mountain bikers on the same test loop twice, once on a conventional mountain bike and once on an eMTB. Average heart rate on the eMTB was about 94 percent of the conventional ride. The riders were solidly in vigorous-exercise territory both times. The part that surprised the researchers: the eMTB riders thought they were working much less than their hearts said they were. The university's own headline called it intense exercise that doesn't feel like a workout. If your eMTB ride felt easy but your heart rate says you worked, trust the heart rate.
Two things go wrong when an e-ride hits your fitness apps.
The assist replaces some of the force your legs put into the pedals. It does not replace the cardio, and the BYU numbers show it. What the motor actually buys you is range: you go longer, climb more, and ride on days you'd otherwise skip because the full climb under your own power sounded like too much. More hours at 94 percent of the heart rate beats fewer hours at 100. For a lot of riders the eMTB means more total training, not less.
Heart rate doesn't know the motor exists. It only knows what your body is doing, which is exactly the thing you're trying to track. So score eMTB rides from heart rate and skip the polluted watts entirely.
I ride an eMTB, and this is a big part of why I built RideTool the way I did. Every ride gets scored in one currency: effort. Each bike in your Bike Profile has an "Effort from" setting, and it defaults to heart rate, so an e-bike scores from your heart while your road bike can keep trusting its power meter. Your e-rides land in the same fitness trend as everything else. No asterisk, no separate category, no re-classifying rides to get credit.
Forget the apps for a second. Pick a climb you ride every week, same bike, same assist level. As you get fitter you'll clear it faster at a lower heart rate. That's the whole story of fitness in one repeatable test: more work, less strain. A good fitness number should just be that test, run automatically across all your riding. If yours is trending up over the weeks, the eMTB is keeping you fit. Keep riding it.
Connect Strava, Garmin, or Wahoo and RideTool turns every ride into a plain-English read on your fitness. Three short emails a week tell you if the riding is working. $29 a year, no ads, your data stays yours.
Start with your next ride