Heart Rate (HR) during Threshold Workouts

Hi all,

I’m in my second week of sweet spot base mid volume 1 and did my first ever over-under threshold workout yesterday (Tunemah). The last set of over-unders was absolutely horrible, but I somehow managed to complete it without reducing the power.

What worries me is the heart rate I’m seeing during these types of intervals. My max heart rate is about 197, and during Tunemah my heart rate ranged from 175 to 182. Thats about 92% of max HR, which seems really high for this intensity (almost in the anaerobic zone, right?).

Is this something I should be worried about? Should I reduce the intensity of the workouts? If nothing else I guess its a prime example of why you should use power over heart rate as a metric for training…

I should probably note that I haven’t gotten around to buying a fan for my pain cave just yet, and I was sweating buckets during the workout.

First off, congrats on pushing through and finishing! Two questions to help clarify: How much fitness are you bringing in? I.e. this is your first over under, and you’re two weeks in to SSB I, so I assume this is your first ever structured training plan? Second, how did you come to the number for your max HR?

In general, I’d say for over unders, that HR is nothing out of the ordinary. O/U are HARD. They are designed to really push your limits aerobically and in terms of muscular endurance and so a high HR is to be expected. Another relevant question would be how you HR dropped in the rest intervals? How quickly did it drop from peak to a low recovery HR?


Looking at your HR on the workout, I don’t see anything out of the ordinary - your heart rate rose steadily and there aren’t any odd spikes or drops, so it seems like there’s nothing to worry about. It’s just a hard workout. If you’ve just started structured training and this is your first over/under workout, just know that it gets, well, not easier, but you get used to them.


Yes @zwillis1 , you’re absolutely right in your assumption, this is my first go at structured training. I’ve also been off the bike for a couple of months prior to starting SSB, so not really bringing in a lot of fitness. As for your second question, I used my max HR from the ramp test (which also corresponds well to what I’ve seen from previous workouts).

During the rest intervals, my HR dropped down to about 140 after 2 minutes.

I would say, then, that your HR is just fine. I looked back through some of my over/under workouts and by the last interval of Palisade (5x9min over/unders), my HR for the interval was averaging 174 (with a max HR of around 190) and I’m at the end of SSBII with a fair amount of fitness prior to starting the base phase.

One good way to measure your fitness is looking at how quickly your heart rate drops to ‘normal’ in the rest intervals and how variable your HR is during the intense intervals. If your HR hits a high and remains mostly steady (as yours does), you’re generally just fine.


in these over- unders I always look for the heartrate to go down in the under intervalls. For me it means, there is the margin to compensate the over-threshold work. For myself, on these figures, I would conclude the FTP setting might be a touch high, maybe 3-5%.

Nice work!
Speaking from my own experience, I’d say your experience of over-unders is exactly what it should be. Over-unders are hard work, and they are hard because… they work.

With no fan, that’s going to make it a brutal workout, and it’s going to push your HR up anyway. I wouldn’t worry so much about the HR you’re seeing there with the info you have given - I say that, but I always watch HR and always compare HR to previous rides too lol. For reference, I did that workout just a week ago, HR on the workout was max 173-ish, and I hit high 180s as a max HR.

Regarding the comment above and the HR dropping in the ‘under’ segments, mine does so just by a few beats and I partially attribute that to mentally telling myself “this is under threshold, this is relief”, and listening to the text where coach Chad also states that relief WILL come in those under segments, sometimes it takes a while. Focus on your breathing and give yourself a mental break after the first 30 hard seconds of not letting power drop too far down.

This is my 3rd season using TR structured training, and all in all, based on my experiences/worries/etc - I say continue on, good workout :slight_smile:

(and get a fan)

Everyone else has addressed this already - but over/unders are brutal - even given the vagueries of heart rate data the values you’re seeing are fine

Mostly posting to tell you to buy a fan. It’ll make a world of difference


While you’re buying a fan, by two of them! My heart rate went up just reading you doing over/unders without a fan. TR recommends Lasco Performance Fans (see Amazon).

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Listen, my friend, don’t worry. I’m 54, my wife is a doctor and I have it on her good authority that I’m perfectly okay thrashing my heart muscle close to its limit on a regular basis.

Like you, I was worried last year (my first Trainerroad year) especially during over-unders and VO2 Max type work, as my HR was very high at times (170+ from a max of 185 and one time I actually saw a genuine 185, yikes!!!).

Hanging on to yet another interval through gritted teeth, lungs heaving and heart racing, there were many times that I thought “is this actually a sensible thing to be doing at my age?” but the fact is that if I happen to have a genetic heart defect it will be found out whether I’m walking up stairs or doing a big TR workout, and like for all my muscles, it’s good for me to work them hard sometimes, as well as give them decent rest too.

Hope that puts your mind at rest. Happy training and good luck, the harder you work the faster you get!

EDIT - yes, get a fan, the bigger the better!!


See? You’re stressing us all out worse than you’re stressed about your HR :wink:

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Haha, I can’t have the stress level of fellow forum members on my conscience, so I just went ahead and ordered one of those Lasko fans @MI-XC.

Thanks for all the great replies! Definitely put my mind at ease.


I did tunemah yesterday as well and I have a virtually identical max HR to you. 198 @ 48 yo

My ‘overs’ averaged high 160s to low 170s at 95 rpm. After the first set I reduced my leg speed and completed the remaining two at a lower RPM

Average HR for the uppers camecdown below 170 @ 87 rpm.

If I had been doing them without a fan, and at a higher rpm of 95-100. I would quite easily expect to see my HR up to 175-185.

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One possible way to lower HR is to push a bigger gear at a lower cadence instead of an easier gear at a higher cadence. I mix it up depending on how I’m feeling from interval to interval. Some of Chad’s instruction touches on that as well.

Wait untill you start doing VO2 max intervals :grin::muscle:

@Anderse Don’t ignore HR. Power in conjunction with HR leads to very powerful information. And if you keep a log of other factors after each workout (e.g. sleep, environmental (your fan situation), life stress, etc.) that may have led to HR being high or low for the workout, you will have very valuable information for future workouts or events.

I think @zwillis1 advice re: monitoring your HR recovery rate is a good one. If you have a spreadsheet of your HR zones, tracking how long it takes you to drop from threshold to tempo to aerobic is valuable (too many details to explain here; but you can google).

Regarding your 92% comment, recreational athletes typically have a ratio of mid to upper 80s that their functional threshold heart rate (FTHR) is as a percent of HRmax; serious athletes 90-92%; world class as high as 95%. Based on your personal description, perhaps you are in the 88-90% category? This means that while you likely went anaerobic, the amount of time you did so was pretty small (judging by your workout chart) and thus, will have little impact on recovery for your next ride.

Keep up the great work!