« Again the Pacing Thing – Fast Starts | Main | Triathlon Purchases by Ability & Experience »



Feed You can follow this conversation by subscribing to the comment feed for this post.

Robin Judice

Joe, thank you for an excellent analysis of the heart-monitor/pacing conundrum. Heart rate can also be a poor indicator when the athlete is dehydrated or hot in a race or workout. Just because HR is over the "limit" doesn't mean they should stop or slow down.

Even when I use HRM's with athletes, we do speed work and races without them... athletes need to learn the motor memory/pacing knowledge/recognition what's happening in their body without the use of the machine.

(And I was a HRM addict from way back, by the way)

I appreciate your time and will share your post.

Robin Judice


Hi Joe, I don't think a HRM is as bad as you make it out to be. I use one to great effect simply by taking into account the HR-lag you describe. For short intervals such as the 3-minute ones in your example, I only pay attention to the HR at the end of the interval and strive to hit my goal HR there. For longer intervals and long endurance workouts, I pay attention to the HR average. For racing, I don't use a HRM and go by feel instead. I think HRMs work well, and I think there is no shame in not having other measuring devices!

Philip Madonia

A trained athlete starts a race with a power output or pace goal to maintain, but in the end, the heart decides whether the athlete can do so, or do perhaps even better on that day. The athlete gathers this info. either from one's RPE knowledge or from one's heart rate (average). If this info. tells one the going is easy, then the pace or power meter numbers are adjusted upward to where the heart leads.
It is useful to know what average heart rate can be maintained over the time frame of a race so that one can rise above pace or power output expectations .


Very instructive article. Thank you!


Hi Joe:

Thank you for the above - I now understand why investment in a power meter can optimize the investment in saddle time.

Sorry to hijack the post. Though, have you time/interest to share thoughts on the value of the likes of Compex muscle stimulator units?


If the athlete is pacing himself/herself well and finishing strong with five intervals per set, how do you decide whether it is appropriate to add on a sixth interval to the set? Is there something that you look for in the power curve of the fifth interval to know that it would be appropriate to add an interval onto the set? Or would you look at the area under each of the recovery phase HR curves (or their slopes) to evaluate the rapidity with which the athlete recovers ? While I depend on my powermeter for a great deal, I am always interested in what the heart rate can tell me too.



You could get a indication of the output using a garmin gps to get the intervall lap speed or distance, this you can use when you ride the same hill and compare the different intervalls, if finishing the last intervalls faster than the previous then you have reached what you want.


Great post Joe! Recently started using a PMeter and had already begun working on using it to pace my workouts in combination with my HR monitor. I hope to use it to help me avoid overtraining when doing my AT workouts as I figure out what my power zones are compared to my HR zones.

On a related topic, I'm wondering about recommended total interval/ ME effort time for a day's workout. Often the recommended effort times for interval workouts total 30min. I imagine this increases during the season as fitness increases, as well as successive seasons as base fitness increases. I know age groups will probably differ as well. Would there be some total effort time guidelines for novice/ Int./ Expert/ Elite? Pro level athletes?

I'm a Cat.2 road rider, 38yrs old. My longest race is 3-4hrs but usually only 2x year. Most of my races are just under an hour (crit.) although several circuit races go to about 1 1/2 hours. We'll finally have a TT champs this year but I don't imagine it will be much longer than 20km.



PS: Does total combined effort time increase as workouts are combined or should the time be divided up for a recommended effort time (ex: 30min. total?)

i.e.: SE day (P1, P2, A2, A3, & S6)

Joe Friel

Cris--Thanks for your comment. But I'm afraid I have to start the answer with my old saw, "it depends." You suggested some things it depends on. I might also add the precise level of "AT" intensity. If it is truly at FTP then one would do less total time in the workout than if it was somewhat below that, say 92% of FTP. And 102% would tilt it the other way. One's capacity for work was mentioned by you. That's a huge one. Then there's one's capacity for recovery. That varies between individuals and throughout the season (base-build-peak). Recovery is impacted by nutrition, sleep, lifestyle stress and what one has done in training in the previous days. This could keep on going. When it comes to "it depends" what any given individual may do is simply too hard to closely define. In general (very "general"), the answer would be some place between 20 minutes and 90 minutes within a single workout. But I've known athletes to do more and not be able to do the minimum here. The only way to find out is through trial and error. Good luck.

Joe Friel

Madeleine--This is a hard question to answer with any degree of confidence (see my reply to Cris' question above for details). Actually, I do it the other way around. I always schedule an athlete to do fewer intervals than I think he/she is capable of based on our experience. Then I tell the athlete to do less if power declines 5% on a subsequent interval or if the motivation is simply not there. It's _always_ better to know you could have done one more quality interval than to find out you couldn't.


Hi Joe,
Thanks for the article. I noticed that you mentioned that it usually takes several minutes for heart rate to catch up with power...(and you said thats good for cardiovascular health and that you wouldnt want it the other way)...well, unfortunately, the opposite applies to me. I find that my heart rate usually spikes right away...should I be concerned? Usually, if I start out embarrisingly slow, I can keep my heart rate where it needs to be for that particular workout...Thanks for any feedback!


Great reply Joe! Your "It depends" answer is much more informative and helpful than perhaps you think it is. THX

Björn from Sweden

Very interesting Joe. One comment though. Back in the day (early 90s) drafting in Olympic races was not allowed hence you needed to pace yourself optimally over the whole distance.

Today its a different story. If you're not out of the water with the rest you're left behind. Drafting changes the pacing-plan completely and it may be well worth doing a larger effort at the beginning of the bike and then (hopefully) be able to settle in at the later part to be fresh for the running. Still, it doesn't diminish your point of using a power output meter.

Joe Friel

Cris--Thanks. Happy to be of help by muddying the water whenever I can. :)

Joe Friel

Charley--I can't comment on whether or not you may have a medical condition. That's not my realm. What I typically see is that high aerobic fitness leads to a slow increase in HR. The opposite is also common.


I'm wondering about mtb races of six to 10 hours rom 2000hm up to 5500hm, would you try to pace the first hills (from 15minutes up to an hour) at the same power as the last hills ? Or would optimal pacing allow for some "natural decay" ?

Joe Friel

Pieter--You're trying to avoid race pace decay as much as possible. Start at a pace which allows this.

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Your comment could not be posted. Error type:
Your comment has been saved. Comments are moderated and will not appear until approved by the author. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.


Post a comment

Comments are moderated, and will not appear until the author has approved them.

Your Information

(Name is required. Email address will not be displayed with the comment.)

Joe Friel's Sponsors

Blue Competition Cycles
"Specialized Bikes is my newest sponsor. I’ve been impressed with their bikes for a long time so I tried one. Had to have it. What a great ride!"

D2 Shoes
"I've been riding in custom D2 Shoes for 8 years. I'm on my third pair. The first two pairs are still going strong. And, yes, they put my cleats midsole."

ADS Sports Eyewear
"ADS Sports Eyewear makes all of my glasses for casualwear, reading, cycling, golf and more. Hundreds of models from all the major manufacturers."


March 2018

Sun Mon Tue Wed Thu Fri Sat
        1 2 3
4 5 6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30 31

Subscribe via Email

Enter your email address:

Delivered by FeedBurner