I am aware that Z2 has been munched over eternally. But I thought I’d put that out there.
I have been experimenting lately with some very constant, top of Z2 training sessions. My idea was to select a flat course with as few descents as possible and hold the wattage for 2-3 hours with little to no pause.
This is what the power graph looks like:
It is quite unintuitive to ride in this way, especially on (small) descents, where I need to hammer it to hold the ~200W. In contrast, on climbs I almost have to consciously hold back a lot to stay in the same zone.
The reason why I ask this question is that I almost suspect this session is too hard. There is no decoupling:
but, my legs feel quite a bit tired after 2-3h of holding the power. HR-wise, the average HR is 145, which is just at the edge of Z1 based on intervals’ model. Still, it is about 10 beats higher than when I was doing Z2 rides on the turbo trainer in winter @220W/135bpm.
No decoupling most likely means you’re pretty efficient at those watts. Increase duration or intensity.
Wouldn’t worry too much about the higher HR. So many different factors influence HR.
Z2 though is a big zone. Don’t neglect the lower Z2 / top Z1.
What’s more important is whether it had any impact on subsequent sessions. If it did, you would be much better off dropping the intensity down and hitting the volume/consistency.
There isn’t much (any?) data to suggest that z2 training is more effective if you do it at your LT1 threshold.
That’s valuable input. To be perfectly honest, I don’t have the time to train more that 3-4 days a week and so such sessions don’t really affect anything as I have enough time to rest. The reason I do it at LT1 is to get as high a load in that zone as I can in the fixed amount of time.
Last week I had this experience of cycling in zone 2 and feeling tired in my legs. But this occurred because I was doing an average of over 3 hours of training every day, causing overtraining. Have you assessed your fitness?
Personally i do my Z2 training based on power but do look pretty close at HR too.
Typically i try to do most of the effort in the upper part of Z2 and average around middle Z2 (because of undulating terrain and unwillingness to take big roads ). So i end up normalizing ~10w higher than averaging. HR wise i will stay between ~62-70% of HRmax.
→ typical results: 80-90 % power Z2 + 10-20% power Z1 and 90% HR Z2 CTS + 10% Z1
If it is high quality or not, i do not know, but i hope so
Regarding unintuitive to ride: for flat and constant uphill riding i actually quite like the pace, regarding downhill i feel the same like you. In practice i try to not drop HR too much on downhills and not worry to much about staying perfectly in power Z2.
About aerobic decoupling i do not worry too much about if i know i have done most things correct, like fueling and regarding clothing. If HR will drift too much though i will not make an extra loop
Interesting that your HR was quite a bit higher for the outdoor ride than for indoor rides with more power. For me it is the other way around or it must be brutally hot outside.
For HR i use the CTS 5 Zone model. In my opinion it represents a bit better the aerobic zone than.
The fact you show no decoupling on such a long ride suggests that this is not too taxing, that maybe you can even ride a little bit harder for your endurance rides. Comparing HR indoor to outdoor can be challenging but certainly 10 bpm is a lot. Maybe just do a few more endurance rides and see if it was just a day where your HR was elevated.
Are you relatively new to cycling? What is your cadence, too low? Both could be reason for your legs tiring, despite your HR saying the workout is easy for you.
Thanks for your input!
Cadence is definitely not too low, my guess is that I am not used to pushing on the flats…
And no, I have been cycling for 10 years now
So many factors to consider…where does this workout come in ones plan (what workout are you coming from, what are you going into next), what time of day are you training (perhaps early morning and fuelled the evening before), what does your gut currently tolerate in terms of carbs p/h, etc…
Whilst I advocate increased carb in take for my athletes, its not one size fits all. It benefits from periodisation (like most things) and not every ride needs the same amount of carbs p/h…
Of course - not every ride needs the same amount of carbs p/h but…
The OP is riding 3 hours at, as he says himself, the “top of Z2”. He needs carbs at that intensity. He also says his legs “feel quite a bit tired after 2-3h of holding the power.”
Unless his bar that he eats every hour has about 60+g carbs he’s not getting enough carbs during that spin. I haven’t come across a bar that energy rich.
The latest research shows that the more carbs you can consume, the better your performance and recovery will be.
I have literally lost count of the amount of people that I know who eat very little per hour on endurance rides but get home and spend the rest of the day with their head in the fridge. The same guys wonder why they’re always shattered at the end of the 4hrs endurance.
Given the symptoms the OP is describing at the intensity/time he’s talking about, and given the fact that he’s eating only “usually one bar per hour roughly” I stand by my assertion that he is not eating even remotely close to enough carbs on that type of training spin regardless of whether he’s fueling the night before or where his workout is in his plan.
). So i end up normalizing ~10w higher than averaging. HR wise i will stay between ~62-70% of HRmax.
