First, when it’s a cutback week you need to add 5 miles to the run despite the exhaustion your legs have been feeling all week because dammit you’ve got better things to do next weekend than run 15 miles.
The night before, try out your new diet of not eating anything because you’ve decided you’re fat and don’t deserve food. At all.
Then, you head out for your run the next morning without eating anything OR drinking anything. It’s imperative that you neither eat nor drink because as previously mentioned you’ve decided you don’t deserve food or drink of any kind. Also, don’t take any water with you. Moses crossed the desert in the 10 Commandments movie with meager rations, surely you don’t need anything for a mere 15 mile run. Suck it up, buttercup!
Start your run with some hills that you know always tire you out immediately, that’s a sound starting place when you’ll have 12 more miles to get through.
When you’re not singing “Manamana” in your head or coming up with new lyrics for “American Pie” by Don McLean, think terrible thoughts of how slow you are compared to some ambiguous, meaningless “everyone else” and get really angry with yourself for how terrible and fat and slow and stupid you are because dammit you’ve got the time to really dwell in the darker areas of your psyche.
At each mile, convince yourself you might be having a heart attack and enjoy the constant feeling like you’re going to pass out because you refuse to consume food or water. Secretly wonder if you can mug someone on the trail for their water bottle and curse those team in training shitheads who insist on throwing their breakfast table with drinks and food in your face even though they won’t share any. “I’D DONATE $50 IF YOU’D JUST STOP SHOVING THAT SHIT IN MY FACE!” you think.
Make sure this run is an out and back with no alternative but to walk/run home.
Then get home and be like, “fuck it, I’m never running again” only to put on Frozen and sing “Let It Go” and then say, “tomorrow, I run!”