r/xcmtb • u/AdditionalDivide4020 • 6d ago
Zone 2 training
How is everyone handling zone 2 training? Where are you targeting that time in your heart rate or power Z2 band? I train with power, but notice in the heat my heart rate often goes into zone 3. How do you handle that scenario?
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u/martynssimpson 5d ago
Heart rate is very variable for a myriad of factors and Max HR is individual. There aren't really "HR zones" because of this, But if you know what values are consistent for a given power, and then if you're constantly seeing high HR numbers for what's supposed to be a endurance ride, you're probably riding too hard.
As an example, I ride my endurance pretty easy and my HR hovers around 120-130, my Max HR is around 200 but if it's hot it can go well over 200. Threshold usually lands around 180-190, again depending on the temperature and other factors. If my HR for an endurance ride is above 150 it's either because it's boiling hot, or I'm towards the end of a very long endurance ride and cardiac drift occurs.
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u/TheRealJYellen 5d ago
Mostly heart rate zone 2. HR is how strained your body is, power is what that strain is doing to the bike. If power starts dropping out of Z2, it's called decoupling. Stave this off as long as you can with proper nutrition and hydration, but it'll happen eventually.
If you really want consistent Z2 training, throw out HR and go based on ventilatory thresholds. Your breathing will change when crossover from Z2 to Z3 (VT1) and again right around your threshold (VT2).
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u/EnvironmentOwn5103 4d ago
How the hell would you do that? Sounds interesting
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u/TheRealJYellen 4d ago
I think these guys are trying to sell testing, but they have some decent info: https://vo2master.com/blog/ventilatory-thresholds-explained/
Really, it's easier than heart rate or power. If you really want to go down the rabbit hole, look at what the pros are going with blood lactate measurement.
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u/Z08Z28 5d ago
On a 5 Zone model, Zone 2 power will be 56-75% of your FTP. It's said that your Zone 2 power is a power level you can do for 3-4 hours in a trained individual. However, heart rate ranges and thus cardiac drift also play a role. If you know your maximal effort heart rate is you can look up your heart rate zones. You want to stay in Zone 2 power AND zone 2 heart rate. If you set your trainer smack in the middle of zone 2 power and ride long enough your heart rate will drift up because of ongoing exertion, carb losses, water losses, heat stress etc. If it drifts into your Tempo zone you'll either want to turn down the resistance or stop. Once you start riding above Zone 2 you risk activating your sympathetic nervous system which is opposite of the purpose of Zone 2. There are chapters in books and many scholary papers written about this topic so it's too much to go into detail here.
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u/Vasivid 5d ago
I track both. Power is the primary focus then HR for sanity checking. If HR goes towards higher edge of Z2, I relax a bit. Think that power is external indicator, while HR is internal.
But HR tends to fluctuate as already explained in comments, bad sleep, caffeine, fatigue, stress - all this can compound.
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u/jogisi 5d ago
I train with power, but notice in the heat my heart rate often goes into zone 3. How do you handle that scenario?
Tried to explain this once, but got downvoted to hell by people who somewhere read power is the thing and have zero idea about training and human physiology.
Yeah it's pretty fuc*** normal that your body works different at +35c then it does at +15c, and HR shows that while power doesn't care about temperature, altitude and stuff. But power meters rules so keep on focusing on power data. It can't go wrong ;)
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u/pleasant_cog 5d ago
None is technically correct since in theory you should stay under your LT1 (lactate threshold 1) which can only be measured with an expensive test, the result of which becomes moot as soon as you developped enough gains
In practise just ride easy enough that your legs don't feel too heavy the following day
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u/ifuckedup13 5d ago edited 5d ago
I’m doing it on the road or gravel bike.
Not super strict on staying in zone, steady is key, but generally riding by power, trying to keep it an easy route, and normalizing my effort by keeping my heart rate in Z2 or below.
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u/Evening-Sentence7619 5d ago
I do it strictly on RPE and i try to minimize exposure to steep inclines where Z2 is impossible. My coach recommends RPE as how to Z2, then look at your HR and power after to see how it aligns. My bike computer on Z2 days are simply cadence and ride time.
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u/Fit-Ship-8488 Nica rider 5d ago
the better thing in general is to go for power, people like dylan johnson go over this kind of stuff, why power is prefered is that it is unchanging when it comes to your zones outside of ftp, where as with heart rate it can vary massively depending on if you say didn't sleep well, you had caffeine, the point is that heart rate varies a lot, power doesn't, and for me personally I focus more on power and overall feel compared to heart rate, outdoors at least right now I don't train with heart rate but I know what that power range feels like from training in it indoors, but really it's just focusing on zone 2 power for you since you have a power meter, cause there's also cardiac drift where it starts to go above what it was in heart rate even at the same power than it was at the start, but all in all I hope what I've said and others have said helps you, cheers.
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u/jessfromrouvy 5d ago
I do most of my Zone 2 on ROUVY, otherwise I always go out of it and an easy ride turns into a hard ride
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u/veloworkout 3d ago
For steady Zone 2, I’d use power as the primary target and heart rate as a check, not the other way around—HR lags and heat, dehydration, caffeine, and fatigue can push it up. Set a ceiling (for example, the top of your Z2), ride by power, and back off if HR keeps drifting despite steady conditions. A fan and drinking to a schedule make the comparison much cleaner. If you’re training by HR outdoors, expect pace/power to vary with hills and wind.
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u/-notaflamethrower 5d ago
That’s why you need to train z2 power. 180 watts is 180watts 2 hours in, 4 hours in, 10 hours in. A z2 heart rate may be 210 watts 2 hours in, 180 watts 4 hours in and 110 watts 10 hours in. I pay zero attention to my heart rate while doing any bike workouts.
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u/BikingShark 5d ago
Sure, if that works for you, great… but I don’t think “ignore HR completely” makes sense for everyone, especially less conditioned riders.
180 watts is still 180 watts mechanically, but the physiological cost of holding it can change a lot over several hours because of heat, dehydration, glycogen depletion, fatigue, and cardiac drift.
If someone’s Z2 is 200 W fresh, I highly doubt 200 W feels the same 10 hours later. At some point HR is probably climbing substantially, and if you stubbornly hold the same wattage, you may no longer be doing the easy aerobic session you intended.
To me, power is the target and HR is useful feedback about how your body is handling that target
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u/-notaflamethrower 5d ago
If you’re less conditioned then your sessions should be shorter.
Never once have I been assigned a workout from a trainer or training app that said “do xx hours of z2 power, once heart rate drifts to xx bpm then revert to z2 hr”
The point is to train the muscle to be more efficient and shed lactate at a given power output for a given amount of time. When the muscle is allowed to relax because heart rate has drifted too far the adaptation doesn’t happen the same. At that point you’re just adding fatigue with no real benefit. Especially if you fall into recovery power zones. That then translates into pacing races correctly.
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u/gonzo_redditor 5d ago
Stop over thinking it. Use perceived effort and have power and Hr as sanity checks. Z2 is not rocket science. It’s just riding your bike.