When you wake up in the morning and you just feel like crap, and you do not want to do anything and you start whining that is when you keep your commitments anyway. You will drag through them, and your performance will suck but you will get them done. Then you can crawl back into the hole you came from and do nothing for a while. But at least you got the commitment done.
This is the exact difference between success and failure. Success is when you do it anyway, regardless of the excuse. Failure is when you let one excuse become another and before you know it several weeks of inaction have gone by. Do not let that happen. Pick your minimum commitment and do it everyday regardless of the circumstances.
That is why I was doing pushups this morning at 5am, feeling like complete misery. I did them anyway, I checked that box. Done for the day.