I have been following a training program this season (thank you, mpl201) that includes workouts meant to be done on your indoor trainer. Recently, the intensity level of these workouts has gone up a notch or two - for instance, last night’s workout called for two intervals of 6.2 miles at between 84% and 92% of max HR, which for me would translate to a range of 150 - 164 BPM.
I have a heck of a time getting my HR up that high on the CT without going into unsustainable levels of effort. Here’s a rough approximation of my power/HR numbers from last night at ~90 RPM (I realize CT numbers are to be taken with a large grain of salt, but they’re all I have to go on at the moment):
225 W / 125 BPM
260 W / 132 BPM
300 W / 140 BPM
I’d say 300 Computrainer-watts is just about (if not beyond) the max I could sustain for the ~16 minutes it takes to cover a 6.2 mile interval on a flat course at that effort level - i.e. 300 W “feels like” it ought to be at least 92% effort, but the HR doesn’t bear me out. If I were exerting that much effort while running, my HR would be over 170. If I’m riding out on the road, I can get my HR over 140 pretty quickly climbing a hill. Most of my outdoor rides are longer, aerobic rides, though, so I haven’t tried elevating my HR for extended periods on them.
Has anyone else encountered similar issues? Should I just not worry about my HR on the CT and go by perceived effort, or is HR too important to ignore? I may try a hillier course next time to see if that makes any difference.
found the same thing, I dont worry about it any more. I suspect its to do with the calibration. I have used different CT trainers and they are vastly different at least in terms of PE v Speed v HRT based on a calibration of 2.5lbs
you cannot compare road to ct speeds and even watts, but test are valid if you do them on the same ct under same calibration and course etc.
Thanks Simon - I was wondering about recalibrating. Won’t it only affect the CT-calculated power and speed figures, though? that is, am I correct that it won’t change the basic problem that my “max” effort doesn’t seem to produce my max HR on the CT?
If you are training to a targer HR, why worry about watts (unless you are using ergo mode)? If you are riding in spinscan and trying to reach 150-164, just keep on shifting until the speed/resistance/watts takes your HR up.
Now, that said, if you have difficulty getting your HR to the target zone, that can be a sign that you are more tired than you may think. Were you sufficiently warmed up?
Also, given enough time at a particular wattage or gear, your HR will go up. Are the numbers in your chart from a 1 minute effort (at the indicated wattage), a 1 hour effort?
Personally, I have a lot more success hitting HR targets when in ergo mode, since I don’t have to worry about digging deep to generate the power, I just have to hang on to the number dialed into the CT.
How did you calculate that 84%-92% of MHR = 150-164bpm? If you used 220-age, then that doesn’t mean crap. You may very well be at 84%-92%, but your “formula” is wrong for figuring out what that range really is
If have you increased the intensity of your workouts, and have also been training hard, then you may be fatigued. When fatigued, your HR is usually suppressed and it becomes much harder to get it going, even when the watts match the effort. That is one of the values of wattage training, since you are measuring actual work. You should be able to calculate wattage zones (just like HR zones) and use these to determine your pace, rather than HR. If you rest up and take a light week to recover, you should see your HR jump back up to where you expect it to be.
Cycling MHR is usually significantly lower (~10 beats or more) than running MHR, since you are not bearing your own body weight. So the fact that your HR would be much higher when running at the same RPE is NORMAL. That is the way it is supposed to be.
If you normally do “aerobic” rides, your body is not yet ready for sustained output at a pace that may very well be above your AT. If you always stay below your AT (except when climbing), then it will take time for your muscles to be able to handle that load. Right now, it sounds like your muscles are not strong enough and are giving out before they really stress your CV system enough to push your HR up. They can be weak from lack of doing this kind of work AND/OR training fatigue.
In summation, go by RPE and watts. You can use CyclingPeaks to help you determine your wattage “zones.” Take some rest, as it sounds like you are upping your intensity to a new level; when rested, your HR should also come back up.
PS: Bumping up your cadence also tends to drive HR up, since there is less torque on your muscles and your CV system is working more. Try 96-100 rpms, same wattage.
I find the CT HR very sporatic and unreliable to the point that I cannot even use it. It is usually “on” for a while and then will drop VERY low, the VERY high. Really all over the board. I would suggest to use your HR moniter if you want accurate info.
Thanks for your input. A couple of comments/clarification points…
“How did you calculate that 84%-92% of MHR = 150-164bpm? If you used 220-age, then that doesn’t mean crap.”
Yes, I admit I used the infamous formula (+5 BPM for running, -5 for cycling) - I have read that it doesn’t necessarily mean much. It seems to line up pretty well for my running effort levels, but not so well for cycling.
“When fatigued, your HR is usually suppressed and it becomes much harder to get it going, even when the watts match the effort. That is one of the values of wattage training, since you are measuring actual work. You should be able to calculate wattage zones (just like HR zones) and use these to determine your pace, rather than HR.”
That sounds like a good idea - I think I will try that on the CT workouts.
“Cycling MHR is usually significantly lower (~10 beats or more) than running MHR, since you are not bearing your own body weight. So the fact that your HR would be much higher when running at the same RPE is NORMAL.”
Understood - I guess I just didn’t expect the difference to be so great (more like 20 - 25 BPM).
“Right now, it sounds like your muscles are not strong enough and are giving out before they really stress your CV system enough to push your HR up. They can be weak from lack of doing this kind of work AND/OR training fatigue.”
Either of those could be factors - this is the first year I’ve done much higher-intensity cycling work.
“In summation, go by RPE and watts.”
Thanks - I think I will do that (before I kill myself trying to get to that elusive 150 BPM figure
Thanks. I actually gave up on the ear clip a while ago and have been using my Polar HRM. I tried the CT-Polar interface for a while but gave up since it requires the non-coded transmitter, which of course doesn’t work with my S-7xx model… (grrr.)
I have little trouble getting my HR up on the computrainer, but as most of the posters have said, the CT wattages can be off at times. So, I think that relative numbers are what you would be looking for when riding the computrainer. Keeping tire pressure and calibration the same from day to day is important in this area.
Another poster mentioned fluctuating HR on the Computrainer. I’ve got two heart rate monitors, one older Polar and one newer one with the coded strap. What I find is that the older one does not want to work as well and fluctuates quite a bit. I don’t know if it is the chest transmitter or the receiver. The other one seems to work just fine. So, it may be the heart rate monitor.
“If you are riding in spinscan and trying to reach 150-164, just keep on shifting until the speed/resistance/watts takes your HR up.”
Even in the biggest gear I could push, my HR just wouldn’t go much over 140.
“Now, that said, if you have difficulty getting your HR to the target zone, that can be a sign that you are more tired than you may think. Were you sufficiently warmed up?”
I think so - the higher effort intervals were after ~30 minutes of lower intensity work.
“Are the numbers in your chart from a 1 minute effort (at the indicated wattage), a 1 hour effort?”
They’re just my memory of what I was sustaining last night (i.e., not worth very much :-). The longest intervals were in the 16-18 minute range.
"Personally, I have a lot more success hitting HR targets when in ergo mode, since I don’t have to worry about digging deep to generate the power, I just have to hang on to the number dialed into the CT. "
Thanks - I haven’t looked at ergo mode but will investigate.
My various training routines are focused around my lactate threshhold rather than my maximum heart rate. And since I train with a power meter, I look first to my LT based on wattage rather than my HR. I still keep an eye on my HR to make sure things don’t get to much out of whack, but so long as I keep within my prescribed power range, I don’t sweat it if I’m outside whay my HR range normally would be.
In other words, if my workout includes intervals between 240 and 255 watts, with a corresponding HR zone of between 146 and 149 bpm, I religiously stick to the power zone, regardless of whether my HR is in the 146 - 149 zone. If my heart rate, however, is way above the zone, then maybe something is wrong (fatigue, etc.) and I consider backing off. If my heart rate is consistently above or below the zone, then maybe I need to re-measure my LT and adjust the zones accordingly.
There are various tests to determine your LT. One way is, after a warm up, do a 30-minute time trial at maximum effort. The average HR and power for the last 20 minutes of the TT will give a decent estimate of your LT, as measured respectively for HR and power. I’ve always done these TTs on the road, as I’m not sufficiently disciplined to tough out a 30-minute maximal effort on a trainer. I’m sure you can find other ways of measuring your LT on the bike that are just as accurate.
I don’t use a Computrainer but I do notice that my heart-rate tends to be lower when riding the indoor trainer as compared to riding outside. I think there are several reasons for this: optimal temperature indoors means less stress, and riding outdoors requires additional energy to balance and control the bike. I still get much higher quality workouts indoors, don’t worry just adjust your target heart-rate accordingly.
FWIW, it seems to me that my HR runs 10BPM lower on the CT than equivalent effort on the road. I know that that does not make any sense, and when I say equivalent effort, I do not have a gauge for it, b/c I do not have a power meter on the road. But I am jealous of your low numbers. When I try to keep up with the “fast” rides or an time trialing, my HR is at 180.
Good post! Yes, LT is what you really need to measure and go by, not % of MHR. I will use LT based CT workouts early in the season and then gradually shift more to power-based workouts in ergo mode as I build to the race phase.
Michael McCormack has some good articles related to all of this on his coaching website.
Thanks - what you say makes sense. I don’t have a power meter for riding on the road, and probably won’t acquire one this year, but I think I will look into structuring my indoor CT workouts more around power/LT than heart rate.
FWIW, it seems to me that my HR runs 10BPM lower on the CT than equivalent effort on the road. I know that that does not make any sense, and when I say equivalent effort, I do not have a gauge for it, b/c I do not have a power meter on the road. But I am jealous of your low numbers. When I try to keep up with the “fast” rides or an time trialing, my HR is at 180.
I’m jealous of your high numbers - perhaps we can meet in the middle
Great to hear that the workouts have helped – two things re: getting the HR up on the CT during intervals:
make sure you calibrate every ride, and
difficulty in elevating HR could indicate that you are under-recovered and therefore unable to push hard enough in those intervals (“overtraining” is more chronic, “under-recovered” just means you would probably benefit from one more day off)
During the meat of my in-season training (build-ups to Ironman races) I will often switch my hard bike interval sessions from Tuesday am to Wednesday am, since the weekends are usually crushing and much harder to recover from.
Just a thought – feel free to email me if you have any other q’s.
