Yesterday, I was doing Mount Field which has (if I recall correctly) speed endurance drills.
Coach Chad on screen recommends lifting you cadence 3-5 revolutions while staying on your target power.
Here’s the problem. I can only achieve this by breaking one of the two goals.
I can raise the cadence 3-5 revolutions (in this case going from 92 to 97) - but then I over blow the power by ~30 watts. Illustration below.
I my raise the cadence 3-5 revolutions by dropping my one gear on the rear cassette, the next step to stay at the target power, means the cadence jumps about 15! Going from 92 to 107!
These exercises are so frustrating and I don’t know what I’m doing wrong or what I should be doing.
Help!
Dumb trainer? Even on my close ratio 12-25 cassette I used to see similar jumps when asked to maintain power and increase cadence by less than 10-15rpm as you have found.
This is one of the reasons I upgraded to a smart trainer.
If a smart trainer, what mode are you using (ERG, RES, STD)?
What bike and gearing are you using? Specifically the cassette on the rear is likely what matters most, but more info can help see a broader picture and maybe offer more options.
Probably you have a big ratio gap between your 2 sprockets. You won’t die if you miss the cadence target. Just prioritize your power target and then try to match cadance as much as possible.
As long as you aren’t physically elevating your heart rate out of Z4 and pushing to bursting point (Edited after below discussion) on a longer basis doing the wo on power but exceeding the cadence target isn’t a bad thing IMO, if anything it should be a benefit to your long term fitness. Pedalling at a higher cadence may push your HR up until you get use to it but in the longer term Z4 or below (Edited after below discussion)is where you want to be.
Mount Field has tempo/sweet spot intervals… Which HR zone model are you talking about? Z2 endurance? or Z2 sub threshold? I know my HR climbs well about endurance (zone 2) rates after about two minutes of high tempo power output.
Yes. Probably not worth worrying about the cadence being only 3-5 rpm higher… Or be happy exceeding the power target by that chunk as long as you can complete the workout.
I should have looked at the workout; when the OP said Endurance Drills I wrongly assumed an endurance one, I see its a Low Level SS one. What I was saying still stands about adhering to power targets even if you are exceeding the cadence target. If the OP isn’t pushing to a longer term burst, pedalling comfortably at a higher cadence IMO is a benefit. For me based on a 5z HR system I wouldn’t want to be exceeding Z4.
But that is the problem and the source of their question here. Just review the info shared (picture in particular), to see that their attempt to slightly increase cadence (white graph line) is bumping a T/SS effort fully into Threshold territory (yellow power line as it gets right under the white FTP line).
That is an excessive change in power and not acceptable since the emphasis should generally be hitting power targets as the primary goal, with cadence as a secondary one. Both cases shared above are less than ideal and would lead me to recommend the rider ignore the cadence aspect of this workout unless they are able to make some other adjustment to keep closer to power target and still hit the cadence recommendations.
There must be something interesting in their setup, because a small increase in cadence seen, is resulting in a rather large change in power. It may be a very progressive trainer resistance curve is one guess, but I am curious to have them answer the questions I asked above so we can try to figure this out.
How do you know from that his HR is pushing to burst when they maintain a steady power to target but increase the cadence significantly (Scn 2 in the OP); the graph relates to option 1 in the OP not adhering to power when you up the cadence slightly.
I did not make that claim specifically. You posted a hypothetical that is great and I am all for. But I countered with the actual info shared for #1 since that is what is posed to us.
IF (and that is a big IF considering what we know as of now) they can make a minor cadence change, keep around power target, that will be fine. But all the evidence points to issues even with #2 despite not having full info to review.
Doing legit Speed Endurance as prescribed is great and I do them myself with great results, usually in ERG. The issue posed here is why the OP isn’t getting that capability and only getting extremes that veer too far off target.
and highlighted If the OP isn’t pushing to a longer term burst ,
It seems to be a specific claim to me. But like I was saying if maintaining a steady power target and exceeding the cadence target isn’t blowing them (the OP) in the longer term it isnt a problem IMHO and its nothing to be concerned with, conversely if it is blowing them, it is a problem and it needs further investigation.
Hello Chad et al,
Thank you for your help with this and trying to figure out what I’m doing wrong. I’m not overly steeped in cycling but just want to get it right, so forgive me if I come off as not experienced. I have ridden a long time as an age group duathlete but not been “nerded out” in the setup. To answer your questions:
Kurt Kinetic Road Machine (dumb trainer).
This would not apply given #1
I ride a Specialized Tarmac Elite. The stock front crank is stamped “53/39” on the big one and “39T-S10” on the small one. I am usually always running on the small as my power numbers (given a person who showed me a graph on this forum before) show that I’m not at the point to utilize the big ring.
The back cassette is 10-speed (Correction: 10 speed, not 11 speed). Is has 28 teeth on the large and 11 teeth on the small.
To answer another poster’s question, I feel in either scenario I’m “working” to “reasonably uncomfortable” but not blowing up. That’s either spinning at 107 to maintain power or cranking at 97 and blowing out power by ~30 watts.
As you will see, the average HR is 144 with a max of 159. It’s exercises that have pushed me over 170 when I have started to feel “ill” light-headed etc. and had to back off. For context, I am 49 years old.
To provide more context (I’m not guarded about where I’m at) here’s the entire graph (below) with all metrics.
Bill
Sounds like you could do with more gears and/or fine adjustment to the resistance I’m not sure if you can do the latter with a KK to do things exactly as prescribed but:
For me for a SS workout that sounds ideal, so IMHO with the equipment you have got you are not doing too much wrong (Sweet Spot is not actually Sweet but its sustainable blowing isn’t ). What I would do is try and maintain a steady power and if the cadence rises so be it you get the benefit of being able to operate at different cadences. In the longer term at this FTP it should start to feel more and more comfortable as you improve at which point its a sign you’ve got fitter and need to raise that FTP. Good luck
OK, the Road Machine is a great trainer (I still have and use mine on occasion), but it’s good to understand that it uses a very progressive speed to resistance power curve.
I found the gear specs for a Shimano 10-speed 11-28 cassette, and then plugged it into a gearing calculator. I did a cadence range from 80-100 rpm with 2 rpm steps, and just used the 39t since that is what you use (and to keep the chart smaller). What we get is a speed estimate for a typical 700 x 25 road tire.
Let’s try one example, 90 rpm start at 39x15 which gets 18.42 mph.
The goal is to hit the same speed (which sets trainer resistance) but shift to an easier gear and increase cadence.
Look at the 17t row (1 shift easier) and see we have to hit 100 rpm for 18.02 mph. That isn’t an exact match to your feedback in #2 above, but it certainly aligns with that trend if you consider it would be closer to 104/106 rpm to hit that 18.42mph speed.
Feel free to digest the table and consider what gears you are actually using. But from this review, it seems like your experience aligns with what I would expect when using the trainer and gears you have. This issue is one reason that many of the old school riders using this trainer often opted for a wheel with a close-ratio cassette. Using an 11-25, 12-25 or similar tight range was done to narrow the gaps between those shifts for smaller cadence steps.
A gearing change might help, but I suspect it will still have some of this issue. You can consider keeping the same gear and just tweaking cadence and living with the higher power, as long at it doesn’t sway too far or cause excess change in your functional demand. Keep in mind it is an option, not a requirement to follow that or any other instructions.
Thanks for the helpful information Chad. There’s a lot to digest there.
I think I will stick to the cassette I have since I just bought it as a replacement a couple of weeks ago.
My gut tells me that I should stick to the power target even if the cadence goes a little higher than suggested. I seem to be able to handle the 107 and I find that, rather than pushing an extra 30 watts, seems to be more challenging in respect to maintaining form so I don’t rock in the saddle or lose my form.
As @HLaB said, “if the cadence rises so be it you will get the benefit” and that’s what I’m looking for.
Thanks for your help with this and it’s interesting to see the science/math behind it.
You said
). What I would do is try and maintain a steady power and if the cadence rises so be it you get the benefit of being able to operate at different cadences. In the longer term at this FTP it should start to feel more and more comfortable as you improve at which point its a sign you’ve got fitter and need to raise that FTP. Good luck 
