How hard is holding a constant power?

This is my first few weeks of training with power and I’ve noticed it is very difficult to hold a constant power on the bike. Every tiny shift in gradient causes some changes. Usually I’m within ± 30W of my target. Is this expected for everyone and will this be something that I’ll get better at over time?

You’re not on your own Martin


It’s a bit of a learning curve but the stronger you get, at least I’ve noticed, the easier it is to maintain a constant power. It’ll take a block or so to get used to it but by the end your normalized for a interval should be virtually identical to the average power! Good luck!


Are you using real time power, 3 sec power average, 10 sec power average or something different?

I recommend using 3 or 10 sec average power.


I find it really difficult outdoors too, especially on flatish terrain. You have to accept that you’re going to swing through the zone pretty widely. As noted above, 3 sec or 10 sec average power helps, and I also use a lap view, and on that screen look at 3 sec power, as well as, lap average power. So if you’re doing an intervals start a new lap and just focus on the average lap power is my solution.

You all! Power is stochastic in nature - its not meant to be steady, that’s not how it is irl or “in real life” as Coach Jake says.

Real world performance and power data is variable - learn to modulate your effort to achieve averages and normalized powers between your zone ranges. For example when you are doing a 15 minute sweet spot intervals its perfectly fine if you power goes above or below 84-97% for a moment or two in order to maintain your speed and effort. What you want to verify is that upon completion you did in fact achieve average and normalized between 84 and 97% of your FTP.

This is why ERG mode gets a bad rap - its not how power works in real world outdoors performance


I do a lot of my training during the weekdays indoors due to efficiency. What that means is a lot of my intervals can be done in erg mode. I’ve made a conscious effort this year to not always have erg mode on during my intervals and try to maintain a watt target like @FRANK describes above. But…if I’m feeling tired at the end of an interval session with one more interval to go, I’ll sometimes turn erg on in order to maintain my intensity level. Basically it helps me to overcome my thoughts about stopping since I don’t have to think about it.

Any drawbacks to that approach?