I've been an avid fitness practitioner for about 14 years now. For the last 7 ish years, I've run 3-4 times per week and up until a recent injury, I was running for an hour at a time, usually about 7-10 minute pace depending on various factors. I also lift weights at the gym 3-4 times per week for 1-2 hrs per session and have slowly built up a pretty fit base doing that for over a decade. Last, I hike almost every weekend as well. I state all of this for a specific reason so you know my background to prepare for the question.
I've recently gotten into cycling due to its lower impact. Today, I rode my road bike for 1 hour and 14 minutes, and tracked it with the "MapMyRide" app. The app has my age and weight, GPS enabled, and so on. I know that running for a given length of time at a given exercise intensity level generally burns more calories than bicycling. MapMyRide stated that I burned 430 calories and traveled 11.91 miles on the bicycle, avg speed 9.6 mph and high speed of 23 mph. During the course of this ride, on probably 4-5 hills, I was at near max heartrate and breathing very heavy. I was dripping in sweat. The workout in general felt more like a High Intensity Interval workout, because on the hills, the intensity was high, flat ground it was moderate, and descents, it was probably almost none. I do feel engagement in my upper body when I ride as well, as my triceps will be toned and slightly fatigued after, compared with a run.
I then went on a relatively light intensity hike. The hike lasted 1 hour and 34 minutes, was 8693 steps, 3.5 miles, and it said that my girlfriend (it was her phone) who is 50lbs lighter than I am, burned 464 calories on that hike. I'm not a pro exercise physiologist but I do know that heavier folks generally burn more calories for a given exercise intensity over a duration, at least when walking or running. So if anything, I likely burned more calories than her during our hike.
This seems incredibly off. Not one time did my heart rate rise significantly during the hike, I never entered even the "fat burning zone", was never out of breath, never broke a sweat, and it was what I would consider to be very low intensity. Whereas, the bicycle ride I really strained. My question is, am I probably right in assuming that the calories burned during the hike are inflated by the app in this case? Or perhaps the MapMyRide app gave me a low number for my ride? Again, I didn't do this in a lab, but I've been working out long enough to know when I am exerting more energy and working harder than when I am not, and that bike ride was much harder for my body physically than the hike was.
Or am I missing something? Do you have any suggestions on why the above situation occurred, how I may be able to fine tune the apps, or perhaps a more accurate way to measure? I know there are a lot of variables at play here and these apps make approximations, so feel free to just throw some ideas out there.