asgelle

Why?

sfrider 

Because once it creeps up over LT it's indicative I'm above threshold power and will soon burn out. Or more specifically, the threshold power has dropped below the power I'm holding.

asgelle

Forgetting about heart rate for the minute, every proper definition of threshold is in a rested state. Fatigue may limit your ability to maintain threshold power, but the threshold doesn’t change.

Second, heart rate drift over time is normal and to be expected. Given the wide range of heart rates that threshold power can elicit, it doesn’t make sense to me to use HR to limit effort. Since fatigue is always multifactorial, it makes sense to evaluate the state of fatigue only on a similar multifactorial, holistic basis.

Seattle Forrest

​​​​​​I agree about power being more useful in pretty much every way. I still wear the chest strap though. It's less useful but still has value.

colnago62

Not for me. At least with most of the riding I do. When I am doing a zone 2 ride, effort is so low that the numbers don’t really tell me anything that perceived effort doesn’t tell me. When I am doing structured work like zone 5 or above, it is mostly flat out and fairly short duration so, again perceived effort tells me what I need to know. Now I do use it when doing sprint type efforts to gauge recovery. I tend to do that type of work from a fully recovered state

asgelle

Do you do any post-ride analysis?

Seattle Forrest

For me, tacos are best but pizza is good too. 🙂

colnago62

I use TrainingPeaks which does a very good job of tracking power metrics in the road. Most of my structured work is either on a trainer or at the track. It is very easy to measure improvement in both situations. I just don’t find heart rate data particularly useful.

Iride01 

If good power meters were as inexpensive as good HR monitors, then many more of us might agree with you. <grin>

colnago62

That is true. It is a much less expensive alternative. Also, if I where running and swimming, I might might find more value in the data. I have SRM Origins on all my bikes and the numbers seem accurate between the devices. One of the things I dirst noticed when riding with power instead of HR, was my heart rate was a smoother with less peaks and valleys. I also noticed after collecting more data that when riding in within a lower power zone, my heart rate never increased so much that I needed to observe it. I began turning off heart rate when looking at data on the ride and after. Eventually I stopped using it for most training.

MoAlpha

Being physician and a physiologist, I like HR and HRV as state measures, but I agree that HR isn’t a very useful live parameter on the bike. It was much better for running, which is more steady-state, and I can remember what a revolution in training the first wristwatch monitors caused. I still look at my power/HR after rides and I also use the regression model that interval.icu builds for you, using a base of rides with power to derive an estimate of TSS from HR for rides without power.

terrymorse 

According to Andy Coggan, zone 2 will increase lactate threshold, but not as effectively as zone 3, and zone 3 is not as effective as zone 4.

I do most of my riding in what some call the "sweet spot" — high zone 3, low zone 4. It's easy enough that it doesn't wipe me out, and it still offers a good training effect.



Sweet spot training

RChung

Andy's schematic was just that, a schematic. That's why the y-axis is labeled "arbitrary units." I think he was trying to express the idea that strain was monotonic with intensity, that duration was monotonic with intensity, and and that training effect should have a peak somewhere at moderate volume and moderate intensity. At the time when Frank Overton came up with the idea, it seemed reasonable that the peak should be about where you could recover from the previous day's ride, but at the time it wasn't based on empirical evidence that this was were training effect would be maximized -- the argument, however, can be cast that the peak must *at the very most* be lower than the intensity that you couldn't recover from. Frank reasoned that getting as close to that point as possible would enable the largest sustainable volume, so that must be where it peaks. I'd say an awful lot of training plans (from Trainerroad, Sufferfest, Zwift, and many many other sources) bought into this idea that the maximal volume that can be achieved at an intensity just below what you can recover from are based on this concept of sweet spot.

And sweet spot workouts seem to work out. But the question over the last few years is whether that's really the optimal workout design. In this case, it's hard to determine because you're comparing something that appears to work (sweet spot) with alternatives that also appear to work. You're not comparing a good thing with a bad thing, or even a neutral thing, you're trying to compare and differentiate two good things.

But I think over the last few years, the scale has tipped in favor of more polarized training as the (slightly) better of the two good things -- or, at least, that's my understanding of the current state of the debate. A way to think about this is that where Andy's original schematic should've peaked? It should've peaked farther to the left. My current understanding is that the real sweet spot is farther to the left, and that another way to think about sweet spot isn't the intensity you can recover from by the time of the next workout, but rather a longer period of time since workout fatigue can cumulate. So another way to think of this in Andy-speak would be that ATL decays more slowly than Andy originally proposed, so sweet spot should be farther to the left.

At least, that's my understanding, and that's how I've been restructuring my training.

terrymorse 

Thanks for the explanation.

So the idea of polarized training is to add in some hard workouts to produce adaptations that you wouldn't get in "sweet spot" training?

RChung

I *think* the actual idea is that long term training adaptations respond more to volume than intensity, and that too much intensity restricts long term volume; so that if it fits within your schedule, you're (slightly) better off backing down the intensity and upping the volume.

One of the real contributions of Andy's work was giving us a way to trade off (some) volume for (some) intensity. That was what Frank Overton was trying to do: find a "sweet spot" that balanced the two.

When I'm time-crunched, I still trade off volume for intensity -- that's all I can do. But when I have the choice to do both, I've given slightly higher priority to volume than I used to, and keeping intensity low. But Berkeley is a lot like Palo Alto, and if I'm going to ride in the Berkeley Hills I'm going to get exposed to a lot of intensity no matter what, so there's a limitation to how low I can go on that.

asgelle

I've been doing and recommending something very similar. Even before sweet spot was coined, I said steady endurance workouts should be done at the highest power that lets you maintain that power throughout the ride and let's you complete all other endurance rides in the cycle (weekly at the time) at that same power. Of course, this is subject to day-to-day variability, but I think the concept is clear. I also think this is consistent with Seilor's observation that world class athletes spend so much of their time below LT1. For the volume of training they do, they are glycogen limited to remain at what is for them a low intensity. Someone like me, however, with my low LT2, can operate much longer at a higher relative intensity without fully depleting my glycogen budget. It seems to me Seilor confused correlation with causation and never looked at why high level athletes distributed their workout intensities the way they did. He just assumed the distribution was what made them world class rather than the other way around.

MoAlpha

Old age may shift the trade-off in favor of a little more emphasis on the higher zones, since the cellular systems respond more sluggishly to training stimulus, or at least that’s what I’m assuming at age 65. Of course, recovery is also slower, so you more pay for those fast days.

sfrider 

That's just a matter of definition. Be that as it may, the reality is that the power you can sustain over an hour is substantially less after four hours of riding than it is after one hour of riding at a similar intensity, which in turn is less than when fully rested. This droop in power sustainable is individual and trainable, and requires something other than power to track and train. Hence, the use of HR. When on hour five of your ride you go above your sustainable power, or get too close to it for that matter, your HR will begin to climb very quickly. This is the indicator that it's not sustainable.

colnago62

It could also mean your hydration level is dropping or you are overheating.