I don’t think this is true! Days of your life are (imo) not defined by the date line, but by the 24-hour periods you experience. If you accept my rules, then as long as you always have flights shorter than 24 hours, you can still run on sequential days.

Edit: you could also potentially run on the plane. I admit that would be pretty weird though

I ran on the Queen Mary II, every day, across the Atlantic :)

Much easier than a plane, though.