how far do you have to run?

you are forced to run:; till you die; till you lose your legs; 10 light years; 5 light years; 2.5 light years; 1 light year; 5 trillion miles; 2.5 trillion miles; 1 trillion miles; 500 billion miles; 250 billion miles; 100 billion miles; 50 million miles; 10 million miles; 5 million miles; 1 million miles; 750k miles; 500k miles; 250k miles; 100k miles; 50k miles; 25k miles; 10k miles; 5k miles; 2.5k miles; 1k miles; 100 miles; 50 miles; 25 miles; 10 miles; 5 miles; 4 miles; 3 miles; 2 miles; 1 mile; 1000m; 900m; 800m; 700m; 600m; 500m; 400m; 300m; 200m; 100m; custom