Entering HR in Fascat Zone Calculator

Hello. I just finished my FTP test to calculate my power and HR zones. When entering the Threshold HR into the Fascat Zone Calculator, do I enter the “peak 20 min” HR or the average HR from the entire hour long ride? It appears that peak 20 min is correct, but when I click the lightning bolt my screen looks a little different than the one in the directions.


Yes use your average heart rate for the 20 minute test.

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Also see our training tip on setting your heart rate and power based zones in TrainingPeaks:

Excellent. Thank you.

Thanks, Frank. I did go over those instructions many times. I think I figured out why it was confusing. Maybe I’m the only one, but I’ll explain in the case it’s a common issue. Prepare for a long explanation, and PLEASE PLEASE PLEASE know this in no way a criticism–just something I realized that may help you make your awesome site and training plans even better!

Perhaps it’s different for other training plans, but for mine: the 18 week Sweet Spot Program, the FTP test/Field Test workout that appears on my TP calendar is an hour long workout which consists of a steady warm up throughout the zones, a few higher wattage openers, a short rest, the 20 min test period, and then a cool down. So when I was done with the test, I had recorded an hour long consisting of many wattages and heart rates. The sample workout that is used in the Setting Up Training Zones tip sheet only shows a recorded workout of the 20 min test period–which I didn’t catch until just now. So originally when I looked at the sample 168 Avg HR I had assumed the the sample test 168 avg hr was the full 1hr workout, not simply the 20 min test. This is reinforced in the fact that the tip sheet directs us to use the 20 min peak power of the workout, so one would assume the test/workout period is considered longer than 20 min. If it was only a 20 min total recorded workout all anyone would need to do is look at avg power because the avg power of 20 min is the same as the 20 min peak power–which can be seen on the sample workout: they are both 219.

Basically, my training program(and I’m guessing others) are given a 1hr workout which includes the 20 min test. Most of us, if not all, are recording the entire workout and not just the 20 min test. But the sample workout is only the 20 min test. This time discrepancy is not a big deal regarding power because peak 20 and total avg are going to be the same–but for HR there is going to be a difference between 20 min test period avg HR and overall workout 1hr avg hr. The tip sheet says to use AVG HR, which one would assume is the avg hr of the entire recorded workout because that’s what the tip sheet uses. The difference is that the workout in the training plan is 1hr and the sample workout only 20 min.

To further complicate things: as far as I can tell the only way to derive the HR from 20 min test period from the full 1hr recorded workout that is given in the training plan is to use the peak 20 min HR from TP. The (possible?)problem with this is that 20 min peak hr is not going to give an accurate avg hr of the 20 min test–my hr at the start of the 20 min period was 145 and at the end 194. It took 2’ 40" after the test for my hr to return to 145. So my peak 20 min hr will include much of the 2’ 40" after the 20 min test instead of my lower HR during the first few min of the actual 20 min test itself. While the power reading is either “on/off” heart rate is going to take some time to ramp up and ramp down so peak 20min HR is not going to reflect a truly accurate avg HR of the 20 min test portion of the workout. Perhaps there is a way to highlight the 20 min test period within the 1hr workout using TP, and then get the avg of the 20 min? I’ll have to try that later.

Hope this helps in some way. Sorry to be so long winded.

Try to “Analyze” the workout and then select on the 20:00 “lap”?

Yes! I just figured that out. And I was wrong about the 20min peak HR and 20 min test portion avg HR being different–they are only off by 1 beat. Thanks!

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Actually, when I select the 20 min lap it doesn’t change the avg hr of those 20 min, it still shows the overall avg. But if I manually highlight the 20 min test period, it does give the avg hr of the 20 min, and as noted it’s only 1 beat different than the 20 min peak avg HR over the entire workout.

Not sure what’s going on there. My peak 20 minute HR doesn’t cover the 20 min test for the screenshot I shared, rather it contains both of the anaerobic steps through some of the 20 minute test. In a previous test, my peak 20 minute HR starts a few minutes into the test and ends a few minutes after the test. In both tests, when I select the 20 min test “lap” an average HR is displayed for the 20 minute interval that looks correct.

Use your heart rate for the power test. It will start lower and finish higher. But he average should be close to your FTP. Since you are technically riding above your FTP by 5% your heart rate climbs through to the finish of the test. But since starting lower it comes out to average out close to your heart rate FTP.

I did the test today (no power meter): CTS 2 eight minute interval with their prescribed warmups. Both avg. Heart rates were 170 bpm. I thought I needed to reset my garmin and so did so --so was thinking an upload may not fit/work. I wondered what to enter in my training peaks and saw some direction from you under thread “training peaks threshold HR value” for another guy who also used CTS: The directions were, go under settings, then to ‘zones’, then pick ‘lactate threshold,’ then coggan method and add sweet spot by multiplying .88 & .97 for low/high on it. Should I use 170 which was my avg or should my entry for lactate be adjusted at all? Also, I’m 58 (don’t know if that makes any difference).

We always use the 20 minute effort and use that average. You could do the same with the 8 minute efforts. And fill into TrainingPeaks as you described.

Hi Jake,
Our family’s going thru our 2nd family emergency in 2 mos & i had to go out of state & am at a motel. I am due for my RM1 tomorrow & then to start hypertrophy monday. However i don’t have good access to determine RM1 (i do have access to stationary bike, can do my Bulgarian split squats, can improvise leg curls with cable, but no access to leg presses.

I’m thinking i may need to repeat this past week’s adaptation as best i can this coming week (as well as bike trainer) and perhaps move my pgm a week down–not completely sure when i can get back home yet.
Any thoughts Or suggestions? I mart wind up falling somewhat behind since i won’t b able to do leg presses and/or mayreduce time on trainer. Thanks
Mark M

Hey Mark,

Take care of your family first!

As for training I would just push everything back a week. Do the best you can this week staying active, doing the movements you can to keep your body activated. This way when you started back up it won’t be from nothing. Also you wouldn’t want to start right up with hypertrophy. So that extra week of adaptation leading into the 1 rep max will be good to get in.

Take care!