I completely agree with this.

I think the important thing is to focus on the long term. Pacing yourself.

My ability to focus used to be terrible. But as with a lot of things, what you practise you get better at. Meditation can help you practise this, and also give you a reset when you're running low on focus.

I recommend being preemptive, and getting in mental shape, getting in shape, and not over extending yourself.

I can easily focus for 2-3 hours, but then I will be trashed, instead I pace myself and work for 45 minutes then enforce a 15 minute meditation session. If I'm feeling burnt out, I might go outside or take a longer meditation session.

My meditation style is: I focus on moving my attention back to my breath every time it wanders off, while listening to white noise.