Stress and fatigue are 2 huge factors...........personally, i know that if i had a rough week @ school and/or work, or im having any emotional problems (friends, family, boyfrineds, etc.).........my focus just isnt in the gym at that time, and its screws my whole workout.................but dont worry, yourll bounce right back to it...............
Strength does not come from winning. Your struggles develop your strengths. When you go through hardships and decide not to surrender, THAT IS STRENGTH