Heart rate too high for sweet spot?

After completing general build low volume, my FTP went from 203 to 219, and I finally got over the 3w/kg mark (started last year in early summer at a measly 145 watts). Today I completed the first training of SSB LV 1, Tray Mountain-2. It was hard but do-able. However, i have a feeling my heart rate during a large portion of the training was too high to represent sweet spot. What do you guys think of these numbers? Did I overachieve on the ramp test?

Did you feel like death? If not I’d put my money on your Max HR being set incorrectly

Here is Tray Mountain (not -2) for me


It could definitely be MaxHR is set too low. It could also be an indicator of lacking base fitness.

It’s pretty hard to say from a general range chart. Take a look at the workout and how your HR ramps and if it levels off.

1 Like

It was quite hard, but only at the last interval I was really counting the seconds.
I’m pretty sure my max heart rate is fairly correct. I’m 35 and put in the maximum HR I observed while going all out in previous ramp tests and outside rides: 186.

1 Like

Maybe this gives a better indication? It slowly creeps up for each interval. I usually start around 155-ish, it levels out in the low 170’s for the last two 12 min intervals.

Maybe I’m a bad comparison because SS has always been a strong suit, or maybe the traditional base I did really worked, but for me this one was surprisingly easy. I know another guy who struggles with SS, everyone’s different.

1 Like

That seems low to me. I’m 45 and my max is 198bpm and my mate the same age makes at 202bpm we are all different though.

1 Like

Intervals uses Friel HR zones AFAIK and that means you need to do an all-out 30+ minute effort. It’s not based on max HR.

Do you know how intervals set your HR zones?

1 Like

I think the zone boundaries are based off of max HR. I believe it initially sets lactate threshold HR as a percentage of MHR. I didn’t update LTHR until today and would get emails after any decent workout what my LTHR had increased from 168 to whatever. Below is my sort of nonsensical HR zones after updating my LTHR to what it settles in at during longer (20+min) threshold efforts. The only thing that changed in the chart when I updated my LTHR was the percentages associated with each zone. All the zones and boundaries remained the same.

Edit: sorry that pic is huge.

1 Like

Something is wrong with your HR zones, or you are an extreme outlier.

1 Like

I’d say a little high. My max is about the same as yours.
So, too hot, humid. much caffeine, lack of sleep?

1 Like

I’m 51, but my max HR has been 180-185 for the past decade. I think I hit 186 once in my life. It’s 182 right now, been coming down little by little.

@Hernia86 My LTHR is 163. When I do short Sweet Spot, I’m usually in the Z3 HR range. For me that is 136-153. Really long intervals would push me up to LTHR at the end. It’s (for me) just a sign of fatigue and relative fitness. It takes me a good bit of work to get my HR up to Z4, which is 154-173. These are Coggan HR zones. Friel has a higher range, and (for example) my workout today (4x10 @ 92%) would’ve all landed in Friel Z2 HR for the entire workout, with a max at the upper end of that zone.

That’s a bit low, of course, as I’m due for a FTP test, just looking at the indicators. The point being, hitting Z6 is not right. So either your max HR is wrong, or your FTP is wrong. FTP being wrong you will know after a week or two of these if you’re completely crushed and Z2 work takes you to the edge of collapse, and unable to recover.

If I hit VO2Max intervals, then all bets are off and HR will stay higher than if I just do steady state work. Even if I hit SS or Z2 after the VO2Max power work, it’s just more elevated from fatigue.

Look for trends over time.


I don’t want to derail the thread, but yeah, my threshold HR is a super high percentage of my max.

I just don’t think the site is using Friel HR zones, since those are based off LTHR and the zones I posted are based off MHR as far as I can tell. I can change the Threshold HR setting and the zone boundaries (z1:0-135, z2: 136-150, etc.) don’t change. All that changes is the percentage column as it appears to be relative to Threshold HR.


Just wondering about your cooling situation.

With an increased FTP, you are doing more work, and therefore generating more heat than you were used to in the past. With an extended SS interval like Tray Mountain, that heat can really build up, and your HR increases as your body tries to get rid of that excess heat.

More fans, more powerful fans, AC, ice can all help manage the heat from indoor training, and have your HR reflect the effort, rather than heat management.


First of all, thanks to everyone for your input!
I’m thinking it might be a mix of factors.
I certainly felt hot during the ride, so I’m looking to moving the bike to a cooler location and adding an extra fan. Tiredness could also be a factor, as in I was riding right at the end of a workday.

My heartrate however keeps puzzling me. I went looking trough previous workouts. These are my results for Eclipse earlier in the year:

I also checked Antelope, and each of the 10-min sweet spot intervals are for a large part situated in the treshold zone.
Time for a lactacte test maybe?

Or just simple “ride at ftp as long as you can”. If you cannot do 30 min at your FTP it is definitely not your FTP. 40-60 min would be ideal. Do the Kolie Moore’s test or something similar. Looking at your HR, I would suspect overinflated FTP by ramp test (very common) or not enough cooling (hot room or quite high humidity).

How do you feel during the intervals? Do you feel your legs but breathing is very stable, or you have to breath quite hard, on a edge of gasping for air? (Not vo2 max gasping but you feel the need of more air?). With SST your breathing should be quite calm, deep but stable.

Third option is your max HR is not your max HR as stated before.

No, its time to understand a few key points:

  • heart rate zones are GUIDELINES and not fact
  • Coggan and Friel and British Cycling are 3 popular HR zone systems and all 3 use LTHR to establish zones
  • I’ve only used Coggan and Friel zones and they provide me with two different HR zones
  • Friel and British Cycling have you do a 30-min all-out time trial to estimate lactate threshold heart rate (LTHR)
  • a nice guy made a free tool (intervals-icu) and it claims to use Friel HR zones
  • somebody above reports that intervals-icu incorrectly uses HRmax instead of LTHR for zones

Here is Coggan HR zones vs Friel HR zones for a ride earlier this week:

Same ride, different HR zone results from two different HR zone systems. They are both based on LTHR.

Certainly something strange going on (rest? nourished? FTP? Max HR?). I’m in week one of SSB MV 1 with a bump in FTP from the ramp test on Tuesday, and Thursday was also Tray Mountain -2. RPE was higher than expected, but I was low on calories for the day. As you’ll see, our power distributions look the same but my HR distribution looks very different than yours. 55 male…

Id say your ride looks good and to me it looks like youre at more of lower threshold power level there at 197 NP being your heart rate crept up through out the ride. Not bad though.

If you want to get technical id say those were 12 minute threshold efforts rather than sweet spot.

But dont worry about sweet spot at the moment and work to get another 12 minute effort at 197NP.

Do you think you could so that?

Then look to do some ( sweet spot ) reps at say 160 NP and do them for 20 minute reps to start.

A good thread.
My question is a tangent. Where do you get these screenshots with Power and HR in TR?