[ZeroFries]

I would say 1) as you have it above, and add a healthy lifestyle in general, then 2) try to pair as often as you can, figure out why your co-workers do the things they do

Honestly all that time outside of work might be better spent just being happy and using other parts of your brain, so that you can devote 6 hours during your work day to focusing on improving. Sure, you can exercise for 8 hours a day and get better progress than exercising for 3 hours a day, but for how long?

Edit: Read more comments. If you got fired for underperformance in the past, it might just be due to mis-alignment between yourself and the manager in charge. I had this at my last job. Sometimes it's tough for managers to properly assess work quality and production speed.