When I was in grade 2 I had an old substitute teacher tell us a story about how he trained his willpower by setting an alarm every night at 3 am and when it went off he’d do 10 jumping jacks.
I tried it that night, got out of bed and did 2 jumping jacks before realizing this was the dumbest thing ever. If I had the willpower to get out of bed in the middle of the night to exercise I already had the willpower in the first place.
But weirdly enough ever since that night I’ve been able to get out of bed on the first alarm