Working on L4 (100% FT - 2x20s) using a HRM?

[sergen]

I've been reading the first part of the 'It's Killing Me' thread and would like to start work on 2x20 intervals at L4, the one problem being I don't own a power meter. However, for the purposes of completing these intervals I would like to establish what heart rate corresponds closest to my FT (which I understand to mean the most power I can output in an hour).

Joe Friel suggests 2 methods of establishing this 'threshold' HR figure (he uses the definition that one's threshold HR is the average HR one would expect to have in a 40K ITT of 1 hour's duration).

The first method is to complete a 10 mile time trial under race conditions and assume the average HR is 105% of threshold. The second is to do a 30 minute time trial under non-racing conditions, hit the lap button after 10 minutes and use the average HR from the last 20 minutes as an indicator of threshold HR.

Does anybody have any experience of using either of these methods to determine the average HR that corresponds closest to their FT? Last year I took part in a competitive 10 mile ITT. I had an average HR of 194bpm, which according to Friel's book suggests a one hour 'threshold' HR of 185bpm. Also, I'm not sure if it's of any relevance but for what it's worth my max HR is 208bpm.

And to those who use power meters - let us assume you do your L4 intervals at 100% FT. Do you notice a general, relatively consistent correlation between your average HR and your 2x20 intervals when conducting them at 100% FT? I'm guessing that there may be a slightly higher average HR on the 2nd repeat due to cardiac drift so I should rephrase the question - do you notice a consistent average HR between sessions when performing your 1st L4 interval at 100% FT?

Many thanks

 

[wiredued]

Using the KK power speed computer 105% TT will have my heart rate between 172 and 173bpm that is always consistant for TT. At 91%FTP for twenty minutes my heart rate is 159bpm during the last 5 minutes of the interval ussually. If the rest time is less than 10 minutes the next interval will be 159bpm for the last 10 minutes of the 20 minute interval if I pick up the pace to 100%FTP HR will be 166bpm aprox. If I don't eat for 3 hours before working out HR is lower at 91% FTP than ussual if I am not feeling well or I eat something within 2 hours of riding HR is higher. Another way of finding 91% FTP is ride at a pace slow enough to take a swig from your water bottle but fast enough to require three quick breaths before it.

I've been reading the first part of the 'It's Killing Me' thread and would like to start work on 2x20 intervals at L4, the one problem being I don't own a power meter. However, for the purposes of completing these intervals I would like to establish what heart rate corresponds closest to my FT (which I understand to mean the most power I can output in an hour).

Joe Friel suggests 2 methods of establishing this 'threshold' HR figure (he uses the definition that one's threshold HR is the average HR one would expect to have in a 40K ITT of 1 hour's duration).

The first method is to complete a 10 mile time trial under race conditions and assume the average HR is 105% of threshold. The second is to do a 30 minute time trial under non-racing conditions, hit the lap button after 10 minutes and use the average HR from the last 20 minutes as an indicator of threshold HR.

Does anybody have any experience of using either of these methods to determine the average HR that corresponds closest to their FT? Last year I took part in a competitive 10 mile ITT. I had an average HR of 194bpm, which according to Friel's book suggests a one hour 'threshold' HR of 185bpm. Also, I'm not sure if it's of any relevance but for what it's worth my max HR is 208bpm.

And to those who use power meters - let us assume you do your L4 intervals at 100% FT. Do you notice a general, relatively consistent correlation between your average HR and your 2x20 intervals when conducting them at 100% FT? I'm guessing that there may be a slightly higher average HR on the 2nd repeat due to cardiac drift so I should rephrase the question - do you notice a consistent average HR between sessions when performing your 1st L4 interval at 100% FT?

Many thanks

 

[acoggan]

I've been reading the first part of the 'It's Killing Me' thread and would like to start work on 2x20 intervals at L4, the one problem being I don't own a power meter. However, for the purposes of completing these intervals I would like to establish what heart rate corresponds closest to my FT (which I understand to mean the most power I can output in an hour).

Joe Friel suggests 2 methods of establishing this 'threshold' HR figure (he uses the definition that one's threshold HR is the average HR one would expect to have in a 40K ITT of 1 hour's duration).

The first method is to complete a 10 mile time trial under race conditions and assume the average HR is 105% of threshold. The second is to do a 30 minute time trial under non-racing conditions, hit the lap button after 10 minutes and use the average HR from the last 20 minutes as an indicator of threshold HR.

Does anybody have any experience of using either of these methods to determine the average HR that corresponds closest to their FT? Last year I took part in a competitive 10 mile ITT. I had an average HR of 194bpm, which according to Friel's book suggests a one hour 'threshold' HR of 185bpm. Also, I'm not sure if it's of any relevance but for what it's worth my max HR is 208bpm.

And to those who use power meters - let us assume you do your L4 intervals at 100% FT. Do you notice a general, relatively consistent correlation between your average HR and your 2x20 intervals when conducting them at 100% FT? I'm guessing that there may be a slightly higher average HR on the 2nd repeat due to cardiac drift so I should rephrase the question - do you notice a consistent average HR between sessions when performing your 1st L4 interval at 100% FT?

Many thanks

1. I would suggest that you not try to "mix-and-match" various approaches to quantifying training, as that frequently leads to the training intensity being higher or lower than intended.

2. Average heart rate during 2 x 20 min efforts (or any predominantly aerobic effort, for that matter) should be reproducible to w/in ~5%, at least under controlled conditions (e.g., constant environmental temperature). As you indicate, however, you can expect to see a steady increase in heart rate throughout each effort, especially the first one.

In any case, how often you do such efforts and how hard you do them will be a far more important determinant of the amount of progress you make than whether you pace them by power, heart rate, or just plain ol' perceived exertion.

 

[rmur17]

I've been reading the first part of the 'It's Killing Me' thread and would like to start work on 2x20 intervals at L4, the one problem being I don't own a power meter. However, for the purposes of completing these intervals I would like to establish what heart rate corresponds closest to my FT (which I understand to mean the most power I can output in an hour).

Joe Friel suggests 2 methods of establishing this 'threshold' HR figure (he uses the definition that one's threshold HR is the average HR one would expect to have in a 40K ITT of 1 hour's duration).

The first method is to complete a 10 mile time trial under race conditions and assume the average HR is 105% of threshold. The second is to do a 30 minute time trial under non-racing conditions, hit the lap button after 10 minutes and use the average HR from the last 20 minutes as an indicator of threshold HR.

Does anybody have any experience of using either of these methods to determine the average HR that corresponds closest to their FT? Last year I took part in a competitive 10 mile ITT. I had an average HR of 194bpm, which according to Friel's book suggests a one hour 'threshold' HR of 185bpm. Also, I'm not sure if it's of any relevance but for what it's worth my max HR is 208bpm.

And to those who use power meters - let us assume you do your L4 intervals at 100% FT. Do you notice a general, relatively consistent correlation between your average HR and your 2x20 intervals when conducting them at 100% FT? I'm guessing that there may be a slightly higher average HR on the 2nd repeat due to cardiac drift so I should rephrase the question - do you notice a consistent average HR between sessions when performing your 1st L4 interval at 100% FT?

Many thanks

HR varies so much. For example here are 3-min avg. HR data from my last L4 workout. 30-min right around FTP:
0-3 142
3-6 151
6-9 154
9-12 157
12-15 159
15-18 160
18-21 162
21-24 163
24-27 166
27-30 168
Avg.HR 158

My range for such intervals has yielded avg. HR's from the mid 140's to the low 160' or about 15 bpm. I don't think I'd ever try to pace off avg. HR.

Back in 2002 when I became switched onto training with power, I did threshold intervals as best I could simply by setting my fluid trainer at the same resistance, same tire pressure, etc. I warmed it up for ~15min past the point of resistance stabilization and simply used a gear and cadence (or rear wheel speed if you have that mount) that allowed me to get in ~20 min without croaking. I was going pretty much to failure on the 1st interval, spinnng for 8-10min and then repeating for as long as I could hold it .. usually only 12min or so.

Essentially I was using PE and trying to replicate my set-up as much as possible without any power feedback. I'll admit I had little idea of progress with this method but at least I was trying.

All these things are good reasons to get a PM. I started on a lightly used PT Pro which is still working well today. No need to break the bank for a SRM or wireless etc.

 

[wiredued]

When I start riding outside in the spring I would like to stay above 76% FTP without a PT can you describe that target in perceived exertion terms? That would be helpful... Thanks

1. I would suggest that you not try to "mix-and-match" various approaches to quantifying training, as that frequently leads to the training intensity being higher or lower than intended.

2. Average heart rate during 2 x 20 min efforts (or any predominantly aerobic effort, for that matter) should be reproducible to w/in ~5%, at least under controlled conditions (e.g., constant environmental temperature). As you indicate, however, you can expect to see a steady increase in heart rate throughout each effort, especially the first one.

In any case, how often you do such efforts and how hard you do them will be a far more important determinant of the amount of progress you make than whether you pace them by power, heart rate, or just plain ol' perceived exertion.

 

[dkrenik]

I've been using speed as a proxy for power on my rollers for several years now. I would recommend a little experimentation to see what speed you can maintain for both 20 min intervals that doesn't "kill" you at the end of the 2nd interval. You can then progress as is appropriate for you.

My 0.02

 

[acoggan]

When I start riding outside in the spring I would like to stay above 76% FTP without a PT can you describe that target in perceived exertion terms? That would be helpful... Thanks

See columns 5 and 6 of Table 2 of this article:

http://www.cyclingpeakssoftware.com/power411/PowerTrainingChapter.pdf

 

[bing181]

I've been using speed as a proxy for power on my rollers for several years now. I would recommend a little experimentation to see what speed you can maintain for both 20 min intervals that doesn't "kill" you at the end of the 2nd interval.

That's about what I do. I have a Tacx trainer, but the Power seems so far out that I don't really trust it for anything - or to put it another way, even if I take what I think my FT power is as a reference, I'm not sure that coming back off that by 5% really IS coming back by 5%.

I know pretty well what my one hour TT HR is, and I just try and make sure I'm around that by the end of the second 20min. On the other hand I like the "water bottle" reference - though wonder if there isn't a "words between breaths" method that could work here as well?

 

[Spunout]

That's about what I do. I have a Tacx trainer, but the Power seems so far out that I don't really trust it for anything - or to put it another way, even if I take what I think my FT power is as a reference, I'm not sure that coming back off that by 5% really IS coming back by 5%.

I know pretty well what my one hour TT HR is, and I just try and make sure I'm around that by the end of the second 20min. On the other hand I like the "water bottle" reference - though wonder if there isn't a "words between breaths" method that could work here as well?

Test on your Tacx trainer, it will give you a value that you can use...on that trainer.

 

[bikeguy]

I've been reading the first part of the 'It's Killing Me' thread and would like to start work on 2x20 intervals at L4, the one problem being I don't own a power meter. However, for the purposes of completing these intervals I would like to establish what heart rate corresponds closest to my FT (which I understand to mean the most power I can output in an hour).

Joe Friel suggests 2 methods of establishing this 'threshold' HR figure (he uses the definition that one's threshold HR is the average HR one would expect to have in a 40K ITT of 1 hour's duration).

The first method is to complete a 10 mile time trial under race conditions and assume the average HR is 105% of threshold. The second is to do a 30 minute time trial under non-racing conditions, hit the lap button after 10 minutes and use the average HR from the last 20 minutes as an indicator of threshold HR.

Does anybody have any experience of using either of these methods to determine the average HR that corresponds closest to their FT? Last year I took part in a competitive 10 mile ITT. I had an average HR of 194bpm, which according to Friel's book suggests a one hour 'threshold' HR of 185bpm. Also, I'm not sure if it's of any relevance but for what it's worth my max HR is 208bpm.

And to those who use power meters - let us assume you do your L4 intervals at 100% FT. Do you notice a general, relatively consistent correlation between your average HR and your 2x20 intervals when conducting them at 100% FT? I'm guessing that there may be a slightly higher average HR on the 2nd repeat due to cardiac drift so I should rephrase the question - do you notice a consistent average HR between sessions when performing your 1st L4 interval at 100% FT?

Many thanks

Yes. i.e, today 30 minutes on an indoor erg at constant FTP+5% even with slightly increasing power during the last 6 minutes, HR over the final 12 minutes was 170 bpm. Bpm during each 30 seconds of that 12 minutes was also 170 bpm. I think my polar HRM showed 171 bpm once out of the 24 times I looked at it. The other 23 times it showed 170 bpm. My HR rose to 160 bpm in the initial 4 minutes, then to 170 bpm over the next 12 minutes with most of the rise at the start. My max HR is 180 bpm. By RPE I felt tired at minute 12, very tired at minute 24, and exceedingly tired at the finish.

-bikeguy