FTP test, low HR, high speed, more?

Hello, I’m new to Zwift, still learning how it all works. Today I did the 20min FTP test and:

It seemed that the warmup and first push were much too easy, My HR never got to 120 until 20 min into the test (120 is about the bottom of my Zone 2)

About the first ten minutes of the test portion my HR stayed within my Zone 2 range, and then the last ten minutes the test became a little harder, topping out at about 153 HR, ten beats below my latest MaxHR check.

I expected the test to be very difficult. It was just a hard effort.

Somewhat related is the speed Zwift recorded was (is always) much faster than riding on the road in similar conditions…flat, etc. I dunno if there’s a way to adjust that.

Low HR, high recorded speed, pretty easy ride most of the way, a little hard the last five minutes. The test result was 239w ave, or 2.85w/kg.

Last question: I have never done FTP test before; I’m 75, slowly coming back from being deconditioned for several months. Aside from all the technical Zwift HR/speed questions, I have no idea whether that’s a good, bad, average, indifferent etc FTP for my age group???

For what it’s worth, Garmin Connect categorized the ride as a tempo ride.

I know, TL, but thanks a million for illuminationg me.

For the 20minute FTP test, the 20 min section is in ‘free ride’ mode, which means it’s up to you to determine how hard you pedal, and for the 20 min section you should be pacing yourself so you end up at the end with no gas left in your tank. If you found it easy, then… you yourself went too easy and the result will not be a good representation of your FTP.

Pacing a 20min test takes a bit of experience, for this reason sometimes people will opt to use the ramp test as their first test, which does not require any pacing, but just to keep going until you can no longer pedal. It’s probably not as accurate as the 20min test if the 20 min test is paced correctly.

The 20min test also uses the currently set FTP to set the difficulty of the first 5min block of the test (to 125% of the currently set FTP). If your FTP is not set to something ‘close’ to your actual FTP, then that 5min section will not do what it’s supposed to do either. What was your FTP set to before the test? If you don’t know, and that 5 min section was easy then it’s unlikely that section was set correctly.

Thanks for the reply, Aaron. This was the first ftp test I’ve done.

The test prescribed amount of power for each segment and I simply followed that.

Perhaps because no data had accumulated, the test algorithm set a low bar?

I guess I’ll try it again In a few days and see if the recommended power output is higher. And I’ll look into ramp tests.

Im still wondering about the high speed shown on the screen vs low perceived effort

Zwift’s 20min FTP test has a 20 min period which is not prescribed, it’s in “Free Ride” mode which enables you to go as hard as you’d like - It should be the strongest effort you can do in that 20mins, and it’s totally up to you to put power on the pedals then. So if you didn’t have a 20min block where you could do whatever you can in the test, then you didn’t actually take the 20min Zwift FTP test, or something else went wrong.

Here is what the 20min Zwift test should look like:
Zwift workouts: FTP Tests » FTP Test (20 min) | What’s on Zwift? (whatsonzwift.com)

The ramp tests, on the other hand, are fully prescribed, and ramp up power every minute until you fail. Those are easier to pace since you just keep pedaling until you’re done.

This is what the ramp test should look like:
Zwift workouts: FTP Tests » Ramp Test | What’s on Zwift? (whatsonzwift.com)

Edit: From your description I’m wondering if what you did was accidentally take the “Ramp Test Lite” which is fully prescribed, ramps up to 250W, would probably give you an FTP about what you ended up with if you go through the whole thing, and then the test just sits there at 75-70W at the end. If that was actually what you did, then you should not choose the Ramp Test Lite, you should instead choose the Ramp Test which will push you to failure.
This is what the Ramp Test Lite Looks like:
Zwift workouts: FTP Tests » Ramp Test Lite | What’s on Zwift? (whatsonzwift.com)

For this there might be a few things going on.

First question: Have you set your height and weight correctly in Zwift? Second question: What type of trainer are you using? (Is it a controllable smart trainer - if so which one?, or a wheel-on trainer? etc.). Third question: What is the magnitude of the difference you’re seeing? What wattage are you pushing, and what speed are you going for that wattage vs what you’re expecting to see?

In general Zwift assumes pretty much perfect conditions, no wind, amazing roads, an awesome bike, a great aero position, etc… So it’s not uncommon to see higher speeds than in real life on Zwift, but if it’s massively far off then it’s possible there’s some other issue there somewhere.

Thanks again for the replies, Aaron. I definitely did the 20 min FTP test (58 min). You are probably right that I misremember the last 20 min, that there’s no watt prescription. I’ll try again later this week to see.

Yes, height/wt are correct, the exercise bike is a Merach S09, which does connect to Zwift and controls resistance for free riding but not workouts.

And your comment about speeds being higher is also probably right, I’m going to quit worrying about that and just ride to HRM and effort.


Spin bikes like the Merach S09 don’t provide trustworthy power data, so anything it says is suspect. You would need a power meter to know your power.

It looks like you are really getting into and hopefully enjoying cycling on Zwift, keep it up.

I looked up some of your other posts and notice that they revolve around your issues with your Merach SO9, which (with no intent to offend) is basically a spin bike. Spin bikes are fairly well known to not calibrate power very well. In your other posts you have said how hard it is to get your HR up and get out of level 1 resistance.

You say above that your test result was 239w and that this would be an FTP of around 2.85w/kg. So your weight is roughly 84kg ?

I looked at your ride activity for your FTP test. After 9 minutes you were averaging 315w and your last half of the 20 minutes was quite a bit stronger. I’m guessing that your 20 minute average was closer to 335-340w. This would give you an FTP of around 320w or 3.84w/kg. Those are some quite serious numbers for anyone let alone a 75 year old returning slowly from a period of inactivity.

So unless you are an ex cyclist (or other sport) of note I would suggest that your exercise bike is misreporting the power and possibly not giving you enough resistance to pedal against.

If you are enjoying your riding do not worry, it should be all about duration, cadence and at a sensible moderate HR. There is no need to be driving your HR through the roof.

However if you are considering any future online racing you might find you are in a race category higher than you possibly should be.

Okay, thanks, Paul. I’m unready to spin the bucks for a proper trainer or spin bike or power pedals that work properly with Zwift and gives accurate readings. I was unaware the budget bike I have would be drastically unreliable. I’ll just ride on as is.

quote=“Ian, post:8, topic:624281, username:Ian_Attoe”]
I would suggest that your exercise bike is misreporting the power and possibly not giving you enough resistance to pedal against.

Yep, either that or I’m taking some serious performance enhancers…:slight_smile:

Ian and Aaron, thanks for your thoughts, I’m going to quit overthinking and ride.


Spin bike power numbers will often be more comparable (not accurate but better for comparison to previous efforts) if you maintain steady cadence and ride the same cadence on subsequent rides that you want to compare. Watts are just a number that says “more” or “less” so for training purposes if you can get consistency out of it that is adequate.

Thanks, Paul, I plan to continue with the exercise bike just as I have with running and cycling for the last umpteen years, using my known HR zones for different ride types, e.g. Zone 2, and forget about all the other stuff.