You can have one extra hour, every day, for the next month. You can't let any of the current demands on your time creep into this extra hour. And there will be no interruptions during this time. What do you do with it?
As of right now, I would spend it consuming long-form writing to exercise my brain. And if I were able to divide the time, I'd use 30 minutes of it to work out, exercising my body.
Now figure out why you aren't making time for that 25th-hour activity in your 24-hour day. Imagine how much happier we'd be if we all found time for our 25th-hour goals.