Carbs Control Strength?

I’ve noticed that when I eat alot of fruit with my diet, several pieces of either apples or bannanas, I tend to have more strenght and endurance for my workouts. Like usually i do incline dummbells and start with 65lbs as a warmup, and work my way to 105. Today I went in and could barely get 70 up. Is it due to lack of carbs, or does anyone think it just could be an off day. I kind of rushed through my worout a lil bit.