[Matt L.]

Currently I am base building but am running only around 30-35 miles a week. I hope to be in the mid-40’s by late September. Since the first week of July, all of my efforts have been targeted at a pace below AeT. I believe my that my AeT is 171 and my AnT is 183, or about a ~7% spread. Over the course of the past three months, my perception of effort seems to correspond with these numbers.. I’m probably due for another test all the same.

The thing is, my heart rate seems to be fairly static for a huge chunk of my easy pace zones. It hovers around 156-158 at what ought to be a Z1 pace (slower than 9:50 min/mi). all the way down to around 8:15-8:30 min/mi. This heart rate is still Z2 for me, but it’s made it really hard to get Z1 work in.

I live in Texas and most of my runs are late in the afternoon, so I’m usually dealing with temps of 91+ and humidities in the mid 30’s at that time of day. When I do work in morning runs, I usually am able to keep it under 150 for a while but I typically wind up hovering in that 156-158 territory by the end of the run.

I should note that these numbers have been reasonably consistent as measured by both a chest strap and a watch. I start to see climbing HR’s above the 8:15 area, but it almost feels like my proverbial speedometer is broken up until that point.

I did have a really wonderful outlier run earlier this week as a storm was blowing in, and my watch recorded an average HR of 138 as I progressed from an 8:26/mi down to a 7:23 over 6 miles. I wrote that off as a trash data because of the wrist based HR, but the conditions were as nice as they’ve been in months and my perception of the effort was easy, so I haven’t been able to shake the thought that the heat and humidity is just messing with my HR and that those numbers might be more accurate than I’m giving them credit for.

This isn’t the first time I’ve posted here about interpreting heart rate data in heat, so I hope I’m not beating a dead horse. Has anyone else had similar issues living in the south? I’d love any tips some of you may have for training in the heat. Should I go as slow as is necessary to keep in Z1? Thanks for reading and I appreciate any thoughts from the communnity.

Topic

[Anonymous]

Anonymous on September 2, 2020 at 10:33 am #44716

Thanks for your patience. Your post was caught in our spam filter. (It’s public now.)

It sounds like your pace is correct or, rather, correct enough. Especially when training in heat and humidity, HR will rise, so given cooler temps and less humidity, I suspect you’d be in Zone 1. Because pace is really what we’re after (and HR is a rough measure of it), I think you can continue as you have been.

With respect to testing your thresholds, with a 7% gap you’ll be better served to get a lactate or gas exchange test. A 60′ drift test would be overly stressful because your thresholds are so close together.

[Dodson]

Dodson on September 6, 2020 at 8:30 am #44780

Well, thanks for your reply and for taking a peek in the spam filter, Scott. I had wondered about what had happened to this post!

I think your answer to this question has tracked with reality. I just finished my first 40+ mile week (ever) feeling fairly fresh so things seem to be about right as far as pacing and intensity are concerned.

With more aerobic work under my belt, I don’t think my AeT has budged since the spring. I always feel a change in gears as my HR turns over ~171. I haven’t ventured above 180 in a long while but with the events I was training for officially cancelled, I’m settling into an indefinite base period and am not as interested in becoming more specific about the top end.

A theory question:

Because pace is really what we’re after (and HR is a rough measure of it), I think you can continue as you have been.

Would you be willing to go into a little more detail about this? I’ve kind of operated under a belief that regardless of my pacing, my HR is the best picture available of my body’s stress. So, even if I’m running a z1/2 pace, if my HR ticks up closer to the middle and upper thirds of z2, isn’t that cardiac stress still something to manage even if the mechanical stress might not be so fatiguing?

Edit: It looks like I remembered my account info from last year!

This is the same as “Matt L.”

[Anonymous]

Anonymous on September 12, 2020 at 10:16 am #44988

Imagine if you were doing a whole bodyweight lifting exercise like squats. What’s more important to track and guide the training: the weight on the bar or your heart rate?

For running, pace is the weight on the bar. For road runners, they should train by pace above all. And cyclists should use power.

But for mountain athletes, the terrain changes, and then so does the pace. So pace no longer reflects the intensity of what we’re doing. So we’re stuck with heart rate.

With thousands of training hours, you’ll bet a better and better feel for what certain intensities feel like. At low intensities, RPE may become useful (although it’s always useless above AnT). And even better is ventilation.

Basically, without an objective way to measure the external load (like pace or power), we need fudgy, kung-fu-like methods to indirectly estimate the external load via the internal load. Heart rate is a good place to start with that.