Sweet Spot Heart Rate

I’ve been doing some digging on the form, but, wanted to see what everyone’s current opinion is.

For a 15 ish minute sweet spot interval that would normally be based on power, in the absence of a power meter, what % of maximal heart rate would you expect a 28 year old male with a field tested maximal heart rate of 197 BPM settle into?

I am currently looking to be around 88-97% of “FTP heart rate” which for me, is probably going to be some calculation based on a recent 20 min field test and the average calculated heart rate for that 20 minutes. Since it’s been a while since I’ve done a proper 20 minute test (thanks to AI FTP), what would everyone’s approach be to this? Should I just go off of percentage of maximal heart rate? Thanks!

For me it’s 85%HR.

That’s 144bpm with a MHR of 170. I hope to be sitting at 144 if I’m going ok.

1 Like

% of “FTP heart rate” (lactate threshold heart rate or LTHR) is what I’ve been taught from Coggan, Friel, etc.

Longer sweet spot for me is usually 90-96% LTHR. My LTHR has been the same (160-162bpm) for years.

You could also take a quick look at HR from completed TR SSB-1 workouts like Tallac, Eclipse, Galena, Hunter, etc. Look if you see a pattern with HR.


Same approach with I agree thats the way I would do it too. I’ve quite enjoyed the lack of a 20 minute field test thanks to AI FTP. The idea about looking at past workouts and the sections of where I settle into HR is a good idea. I’m gonna take a look thanks!

1 Like

About 155 BPM for me out of a maxHR of 185

It’s what i use when i’m outside on my MTB with no power to estimate that i’m about at Sweetspot.

How long does it take to get up to that HR? For me for SS, it takes ~10 mins+ to stabilize at under LTHR which is a good indicator I’m in the right zone.

My LTHR has shifted recently following Covid so I’m not 100% certain that it is usable for this. I find the number from MHR reliable for my uses, same with LT1. These being not strict limits, but I know I’m in the zone when I’m pretty much right on that number.

For me I’d have to be riding “high” SS to get to the 85%MHR in 15mins. Conversely, if I get up to it too quickly I know I’m battling, or if I start to drift up from that point the same.

Depends on a lot of stuff. First ride I pulled up was a 1x40-min in early season 85F heat, and within 2 minutes it hit 93% LTHR and it stayed at that HR for the remaining 38 minutes. And my coach has me doing a lot of hard start SS, say 1-min above 110% and then 9 minutes at 94%. So those bring up HR and generate a surge of lactate from the start, and then a longer tail to remove lactate.

For long threshold efforts it takes 10+ minutes to reach LTHR.

After a month long off-season my LTHR shifts from ~160bpm to 154-156bpm, and then within 4 weeks quickly rebounds back to ~160.


That’s an individual thing.

I see what you’re saying. I haven’t tracked LTHR following off season as I don’t usually do any Threshold work during Base.

With regards post-Covid changes. I’m putting out some lifetime best numbers, so I don’t think it’s deconditioning. There is potential that it’s an increase in cardiac conditioning :man_shrugging:. The post-Covid increase seems in line with a lot of what I’ve read (and what Kolie Moore has seen as a consistent reaction), but I don’t know the mechanism.

My understanding is that if your FTP is a high % VO2max, then that increases your LTHR as % Max HR.

HR is individual but with a max coincidentally of 197bpm anything over 95% max for me is a sprint and my SS will sit some where around 89% max. I like to use the max figure simply because that what I am used to and can process quickly. But other methods are just as valid, just pick what works best for you.

Individual indeed, 92% HRmax for me is riding around threshold, so 95% HRmax just getting warmed up in a longer vo2 effort.

HRmax makes it difficult to compare across athletes, hence one reason for using % LTHR and % HRR (heart rate reserve).

What I process is all from memory: 143bpm is the top of endurance, 150bpm is the top of tempo, 154bpm is the top of sweet spot, and 160bpm is riding around threshold.


It’s definitely possible it’s just related to a reduction in VO2max following Covid. Based on my numbers since and sensations/HR at rest and exercise I don’t think that’s what it is.

Either way, I really like the consistency of the values from MHR and they have worked well for me for the small amount of use I have for them.

Definitely there’s a heap of value in LTHR values, I was just providing a point about how changes in LTHR can be for a few reasons :grin::love_you_gesture:.

FWIW I see more changes in HRmax from training. My standing joke about having covid a couple times now is that my Resting HR decreased 10bpm, I got faster, more durable, easily lost weight, and quicker rebound after a period of detraining. I don’t actually believe covid had anything to do with any of those things, but like they say lies, damn lies, and statistics. Because all of those things happened after having the delta variant of covid. So it must be correlated and true :wink: :rofl:

95% LTHR (Friel). 85% MaxHR.

By the end of the interval, it should not creep up to threshold HR. If it does, dial back the power during the next interval.

If you lower to 75-80% MaxHR, you can do longer intervals (more TiZ), good way to address muscular endurance limiter, spice up base training, climb a hill during an otherwise endurance ride, extend TTE, and ultimately do more work in, for example, a six week period. Give that some thought.

Thank you. 85% max today in the absence of a recent LTHR test (I’m talking months since I did a proper one) felt pretty good. I’ll get back out there and crack out a proper LTHR test, but, for now the % of max heart rate worked out well. I am venturing back into intervals again as I prepare for a local community bike race and certainly need some higher intensity built in to a plan again. I’ve enjoyed the luxury of long summer rides with not much focus except aerobic base building. Should have a solid foundation to build on by now.

1 Like