If you have every truly pushed your body for long periods and under heavy loads, you know exactly what it feels like to do The Hardest Squat of The Day.
It is always that first squat where you force yourself under the bar and try to unrack it. It doesn't matter how much Horse Liniment you've covered yourself in or how many hours you've foam rolled or run your shoulders through a sand blaster...that first set will always be the toughest.