HR zones versus power - do they align?

Today I have been wondering if HR and power zones usually align, albeit with different ‘curves’ if plotted on a linear graph - imagining power as a straight line then does HR typically increase at a lesser rate to a certain point then ramp up quickly until max?

(Notwithstanding variations to HR caused by fatigue, sickness etc.)

Below is why am thinking that.

Did Baxter today for the first time in a very long time, started SSB1 from scratch this week so did ramp a few days ago.

Unusually I had an HRM on, almost all my training has been RPE or power alone. Shocked me that the higher zone 2 into zone 3 power stuff hardly moved my HR or RPE for that matter.

Mostly I was in zone 1 for HR, only nudged into zone 2 for the tempo intervals and only by a couple of BPM.

As background I have taken some time off the bike for last month and not trained much since late November. Baxter felt very easy, never uncomfortable in the slightest. FTP on recent ramp was around 10 watts lower than November (from ramp and 20 min test)

Some existing info worth review (if you haven’t seen it already).

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Not seen that before thanks Chad, somehow missed that searching the forum!

Everything linked there raises another few questions though.

Do we need to, or should we, elevate heart rate to gain ‘fitness’?
If so to what level and for how long?
Would 90 mins in HR zone 1 still give meaningful fitness benefits?

Reason this is important to me is lack of time. I am doing LV as it is achievable with all the other things going on. That means every second on the trainer needs to offer as much value as possible, be as broad as possible (train every system), and of course not burn me out/lead to injury or undue time off.

The low-volume plans are explicitly designed to hit training goals as efficiently as possible. SSB1 ramps through gentler endurance/tempo workouts in the first week to sweet spot and over/unders for the rest of the plan. If you’ve been off the bike/off training since November, that might be what you want. Baxter isn’t supposed to put a lot of stress on your heart; it’s supposed to get your body accustomed to pedaling continuously for 90 minutes so you can do the rest of the plan without injury or burnout. It’s the only low-intensity session in the plan.

Also keep in mind that SSB1 isn’t designed to “train every system” – really none of the plans are. Base builds your aerobic engine, Short Power Build trains your VO2max and up at the expense of endurance, Sustained Power Build trains your endurance at the expense of VO2max and up, General Build hits everything but not as hard, the specialty plans laser-focus on energy systems specific to the event type, etc. If you feel like your base is already deep enough that three months without training didn’t really make a dent, you could always hop directly into SSB2 or a build instead.


Depends on how you define “fitness” - general health fitness or race-ready fitness?

Developing any/all levels of fitness will require some level of elevated HR. However, training general fitness does not require extended time at HRmax etc. Brisk walking is considered one of the best forms of developing cardio fitness; 30min/day @ 60-65% HRmax (HR Z2) will do a body good!

Then there’s the MAF Method (aka low HR training). If VO2max training is raising the roof, then MAF is raising your floor. This takes a lot of time, both acutely and chronically. But it works. Again, done at a nose-breathing pace (HR Z2/VT1/AeT).

Race-ready fitness will obviously require a lot more time in higher HR zones.

Unfortunately, 90min in HR Z1 is kind of wasted time unless you are coming back from illness or injury etc. Z1, both HR and power, is more for recovery than developing fitness.

I’ll stick with SSB1 for another week and see what happens.

Did Goddard last night and only just crept into HR zone 2 in the 6 minute SS bits at the end.

My HR is tracking my power closely and responding quickly but sitting lower than I have ever noticed. On the ramp test I was just a couple of BPM lower than my max from ~4 years ago when popped, so it can still get up there.

point of reference…

When I was fit, my HR was Z1, and barely Z2, for tempo work. It would also vary by time of day. My morning workout was always lower than my evening workout. Sweet spot work would nudge me up a bit, and I could hold that HR for over an hour, with 20 minute sweet spot intervals. A 3x20 @ 94% would bring me up to the “appropriate” zone on the last one though.

I very much use HR to gauge my aerobic fitness, but largely ignore it for workout guidance. I also use HR to track my time to “blow up” approximation, and overall strain, on hammer rides with lots of surges into Z5/6/7.


I’m wondering if doing lots of hour plus walks on holiday did me some good last month? Either that or it was drinking loads of beer…

Try a fresh battery in the HRM, if it’s suspect. I know my Wahoo Tickr, when battery is low, reads a near constant value, that’s just wrong.

Some ~90% intervals got the heart moving up to ~78% of max HR. Must just be those first few workouts not having sufficient stimulation to get the HR up.

Just to close this off - I used another battery for one workout and another HRM for another.

90% FTP equals 70% HR. This is the same at 80RPM or 105RPM. RPE is low during but after workouts my legs feel used.

Be interesting to see what my ramp result comes out at. I’ve previously been weak aerobically and strong anaerobically, and ramp tests have come out with a result higher than my 20 min result. This time around I don’t feel this is the case.