Of course everyone is different, but there are at least some studies the does lend credence to the "willpower as a finite resource" theme.

As someone else mentioned, that study has come under fire. It's also one I never agreed with because for me personally it wasn't true. I have always found things like discipline and willpower to be more about inertia than anything else.

If I wake up and start playing a video game or eating crap, that inertia carries through the day. The reverse is also true, if I get up, workout, and start being productive that will carry through the whole day. Once I realized this about myself I adjusted my whole schedule around. Instead of after work workouts, I moved them to the morning. Instead of staying up late, I get up earlier and naturally go to bed earlier. So instead of wake up and chill and ease into my day, I wake up and go. And, that go carries through the entire day.

The way I look at it, you can push past your ordinary daily soft limit in this area, but there will be a cost, and the more you disrupt your routine in pursuit of your goals, the higher that cost will be-- past a certain point (likely different for everyone), you will get diminishing returns & risk of a breakdown goes up.

The balance to strike here, I think, is to give your mind & body a chance to recuperate before you get too close to that breaking point. Or phrased another way, look at 'pushing yourself into a second wind' as a critical tool for certain situations, but one to be used sparingly (preferably when you have some open calendar spots ahead).

There's only really one study that backs up the "willpower is finite" thing, and it has failed replication.

https://getpocket.com/explore/item/the-way-you-think-about-w...