Doesn't feel like I'm working hard enough during rides?

Hi all - been riding indoors for a while now, previously on a dumb trainer (one of the Elites) and usually had it set to resistance level 4 and maintaining 90 rpm and I’d be watching TV shows on my tablet for however many miles I needed to hit (typically 12.5 - 20 mi during work week). Through this method, I felt like I was simulating my outdoor rides at similar effort level (17 mph average, 140 HR average as well), and noticed I would typically burn about 200 cal per 5 miles.

Recently got a smart trainer (Tacx Vortex Smart) and was using BKOOL Simulator to try it out before switching to Zwift as I kept encountering connection issues with my tablet (I had a low power Chromebook, so maybe that’s why). I’m using my Moto X4 phone now to run Zwift since I can’t download Zwift on my tablet. No problems there.

The issue I have though, is that I’ve done few 12-16 mi rides and I feel like I’m not working hard enough. Trainer seems to be calibrated properly and it says it has the latest firmware updates. Sure, this probably will depend on the terrain and such in Zwift, but while I could reasonably expect to burn 500-600 cal previously on my dumb trainer before and ‘felt’ like I had a solid workout, on my Zwift rides, I’m barely clocking 400 calories and didn’t feel like I had a solid workout per se. I will have to admit, a lot of the rides were on flat parts of the desert or the ocean parts and not enough portions were on climbs. I did change the difficulty setting to 100% since I noticed 3-6% climbs felt a lot harder when I would ride in BKOOL Simulator, but last night after having done the Deserts and Sequioas route as well as the Volcano routes few days earlier, I still was burning barely 400 calories, averaging a bit faster at 19mph or so which seems a tad fast. My HR average is also hovering a bit lower around 130 as well.

What can I do to make effort levels more realistic? Do more climbing courses? I haven’t taken a FTP test yet, I’ll probably need to do that, but it’s currently set to what I’d expect it to be like which was also validated through using BKOOL Simulator (200W).

Hey Walid, welcome to Zwift!

My first suggestion was going to be put the trainer difficulty at 100%, but you did that already!

2nd, I’m not sure how the Vortex works, but make sure it is tight enough against your rear wheel, as per the manufacturers directions. Also, make sure your rear tire is inflated to the proper psi, usually 100 - 120, again there might be a recommendation from Tacx on this setting.

3rd, how are you measuring calories burned? This is always just a wild guess of a metric anyway, so not sure you should be using it. Heart rate is going to be a better measurement here. Your old trainer had a constant resistance, and the new one will change depending on the Zwift environment, so on flat roads your heart rate should be lower. I think this is probably normal.

4th, do a spindown calibration to see if that makes any difference.

Ride on!

Another thing, you really cannot compare outdoor rides with Zwift rides as far as speed goes. In Zwift you have no wind, no stop signs, no reason to slow down for curves and much more drafting.

I also agree with @Mike_Rowe_PBR calories are at best just a rough estimate (calorie intake is even a worse estimate) and should not be used as a metric to judge fitness or difficulty of a workout, HR is a much better option.

I can keep my HR at or below 130 and still do 20mph on Zwift while on the flat courses. I use a combination of HR and watts during my time on Zwift and totally ignore calories even after the ride/run.

Totally forgot about tire pressure, I know I made sure to have it at 110 psi when I first got the smart trainer, but I have not checked since, so will make sure it’s in range again and calibrate. I do have road tires on there and wonder if that’ll make a difference. I considered buying rear wheels and tire just for indoor rides.

I forgot to mention that I used to have speed and cadence sensor with my Garmin Forerunner, so the calories I stated are what Garmin Connect shows me. I understand it’s more of an approximation, but I definitely can feel the difference in effort level, I would be pretty tired after riding for an hour on the dumb trainer, whereas after Zwift workout, sure I’d sweat, but my legs felt not as fatigued. Looking up differences in actual calories burnt from my workout data just proved in numbers what I felt in that I wasn’t working as hard in Zwift workouts. It could be differences between how Garmin estimates calories burnt and how Zwift does it, but that’s 200 calories off, which is significant enough (especially considering that’s approx 5 miles of work)

I tried calibration after workouts too on Tacx Utility app and it was still within range. Is there a different spindown calibration that Zwift offers?

Totally understand that, I typically ride solo outdoors, so don’t benefit from drafting, but even when I’m going 18-20 mph at 0%, I still feel like I’m working, while in Zwift, it seems almost like it’s default just by spinning, so that’s why I perceived it as ‘easier’. I don’t know what my watts was when using my dumb trainer, but there is considerable difference in HR between before and now. Granted, that probably can be explained by the fact that there was constant resistance before while there are more cases of flat or declines riding in Zwift, which might explain less work being put since if that was outdoors, I’d likely not be pedaling and coasting.

I use Rouvy as well as Zwift and climbing at the same grade is much more difficult / realistic on Rouvy.

OK, so I made sure to calibrate before and after, took a FTP test, adjusted the difficulty setting and now rides are definitely more realistic… I’m definitely working when I’m climbing up those hills.

It seems though, that now I have the opposite problem… I think it’s too hard now? Like on 0%, I’m hardly getting up to 90 rpm and even at 70-80 rpm my speed is going 20+ mph. I tried out one of the flat courses in London and even when it was flat and maybe -1%, I noticed I was working a lot harder than before. Calibration seems to be in range, but I seriously doubt I’m cranking out 160W when cruising on flat terrain going 20+ mph? What did I do this time? The difficulty setting is back to 50% and I still feel like I’m having to push just to ride on flat surface.

Same problem here @gtg007w, I havent had a chance to explore why, but today I have some time to play around with calibration and settings to see whats going on. I tried recabriating my Kickr Snap last night but the Wahoo app wouldnt complete a simple spindown.

Wheel on trainers are known for inaccurate power readings,honestly the only way to know for sure is to run a direct driven trainer or power meters if you want real numbers!

Yea, I only ride with a powermeter on the bike, they are not expensive anymore.