Ftp builder and cadence

Hi all,
My name is Ria, age 61, started mountainbiking 3 years ago, twice a week, and started recently riding on a Saris for winter months. I have an athletic background, but new to this, so I thought to try to do the ftp builder. I am around 60 kg, did the ftp lite test, ended up with 143. Am doing the plan, finding everything doable, even easy regarding wattage, except……when I follow instructions on cadence, (which is hard on my Saris with such low wattage, and often the cadence info becomes erratic due to no resistance to pedals, I have ERG on) my heart rate goes up consistently and I end up riding constantly in the 4 and 5 heartrate zones! In itself this does not feel too hard, but from what I read I am also supposed to be in heart rate zone 2?
I adjusted my heartrate max to 174 bpm instead of 159 bpm (age implied), I regularily show on my mountainbike rides with a heartrate monitor 174, also adjusted my rest heartrate to 58, which helped somewhat, but in zone 2 I still am supposed to stay under 140 bpm, and when I follow the cadence suggestions, I end up riding consistently around 145-160 bpm. Should I ignore cadence instructions? Or lower ftp (but I already feel I am hardly getting a workout), or ignore heart rate numbers and just do as the program tells me?
Any advice greatly appreciated!
Newbie Ria :grin:

It may help if you say what model of saris trainer you have. You say a lot in that post so I’m not sure what is going on, but some possibilities:

I haven’t done the ftp builder plan, but I have done others and they do start out quite easy so it’s a possibility that is why you are finding it easy.

Heart rate - I rarely see my max heart rate so it’s possible your max is higher than you think. For me to hit my max I need to be doing a sustained (5 - 10 minute) effort over ftp and then do a sprint or something similar to finish me off! On a ramp test I think I’m usually about 5-10bpm below my max.

I do workouts according to power, I don’t really pay attention to my heart rate at the time. I sometimes look back at my heart rate over sustained periods to look at trends.

Your cadence issue, when you say there is low power is that because the training plan is asking you to do a high cadence at a low power or the trainer isn’t providing you with sufficient resistance? Generally I try to meet the cadence targets in workouts if they specify one since I think there is a purpose for doing that. An exception is if you have issues (maybe knee problems) that could be made worse with high or low cadence.

Hi David,
Thank you for responding! The Saris is a T3 or N3?

The max heartrate I just get from Mountain bike rides outside when I have a heartrate monitor on, and then my max heartrate in a ride was 174 bmp on strava.

When I need to do low power , high cadence in the program (100 rpm to 110 Watts) the cadence measure becomes eratic; fluctuates from 54- 115 back and forth, so it is really hard to try to ride at a constant cadence because I basically don’t have a cadence measurement anymore!

The other problem I have is that I can easily follow the power request in the program at a lower cadence and my heartrate stays in zone 2,3, but adding the high cadence raises my heartrate into zone 4 and sort of stays around zone 4, and sometimes even reaches zone 5; this happens when I do the “foundation” rides? So I wonder if that is the wrong kind of training, because aren’t those rides meant to be lower heartbeat and power rides?

So I have basically 2 questions:
-how to ride high cadence when the Saris doesn’t work the cadence anymore

-whether to lay off of the cadence demands in foundation rides, to keep my heartrate in check, or just ignore higher heartrate and follow cadence demands

  • another thing that has come up in my strength training: it asks for 240 W but also says to go all out for 10 sec: if I go all out for 10 sec I ride at 350 Watts. Should I keep it at 240 or go all out?

Thank you so much for trying to help me and respond, David, I am new at this and love some guidance!

Many thanks,

You could try looking to see if you have the latest firmware on your saris and see if that helps with the cadence issue. If you are really bothered by it you could buy a separate cadence sensor to get more accurate readings.

You will have a higher heart rate for a given power with a higher cadence vs a lower cadence, but this is (at least in road circles) considered good as your heart can handle higher stress for longer than your legs can, I’m not sure this translates to mountain biking though. I would say though I used to be a low cadence cyclist and after a Zwift training plan I am a higher cadence cyclist now and it is useful being comfortable (or at least used to) different cadences.

Personally I’d try to stick to the cadence targets for 2-4 weeks at least (as long as you don’t feel undue discomfort). Some of them are supposed to be uncomfortable and will help you get used to different cadences. If your cadence sensor is acting up then just got by your own best estimate

Thank you David! I’m going to do that!


If you are using the Saris for cadence, it can get flaky. Inexpensive cadence sensors are available on Amazon.

I use the H3 for cadence and it is pretty good. I have a cadence sensor but don’t pair it anymore because I am happy with the H3.

This probably show that I don’t have a very smooth pedal stroke…LOL

I used the H3 when I got a new bike and was too lazy to transfer the Tickr sensor from the old bike. Cadence would be stable for a 20 minutes and then start cycling between 45-85 (actual 85). Then go back to normal. So I picked up an inexpensive one from Amazon and much better.

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Hi Chris, yes, it is H3, and thank you for helping me out! Do I hook up an inexpensive cadence sensor independently from the Saris?
I’ll go look into that!

Thank you! I will do the same!

Hi Chris, is the Garmin cadence sensor 2 any good?

The Garmin will work. This is the one I purchased at half the cost and it has worked well: https://www.amazon.com/gp/product/B085NQS2F6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

Thanks, Chris!

just FYI - high cadence training hits the cardiovascular system more than leg strength, so it is not unusual for heart rate to be higher at a high cadence.

“foundation” rides are to build up a base level of fitness, if you are not used to cycling at 100+ rpm then heart rate will be high until conditioning improves.

i would say ride to workout cadence/power demands and ignore heart rate (unless you are blowing up, in which case FTP is potentially set too high).

I view the cadence goals as a suggestion.
I use 1x9 bike on a dumb trainer.
I always hit the power and I try to shoot for the cadence but sometimes I just don’t have a gear that lets me do it.
Still, if the interval is a high rep interval, I’ll get as close as possible and the same for the low rep intervals.
One works the cardiovascular system and one works the leg muscles.
Neither is how I would ride ony own.

Thank you Ben!!! So you say that once I get more used to the high cadences my heartrate shall go down, correct? No, I don’t blow up (I think, am not totally sure what that means) I don’t have a problem condition wise riding for 30 min with a heartrate in the 150-ies, I am used to that from Mountain biking.
It is nice to know what to do now, and not worry that I am doing it all wrong. Thank you so much for sending this email!

Ah, thank you Tim! That was very helpful! Since I am more a mountain bike rider and only thought of riding the trainer since the weather is getting worse, I never even considered cadence as an important thing, I always try to strengthen my power. I guess I am going to do what you do, at least try it, power and then cadence, to work both systems!
Thank you for taking the trouble to email me!