At least Atomic Habits says it's more important to show up. Like a good way to start a running habit is just to put on your shoes every day even if you don't run.

So here just going to the gym could be enough to check of the box for the habit, rather than say you failed if you don't do the whole 25 minutes or you feel like you wasted time at the gym.

You of course can build on top but it's good to have that fallback minimum.

You're gonna do better at building the habit working out for 1 minute per day than 7 days in a row for 60 minutes, a few times a year.