Prepare your body for intensity by stretching before Fencing. It gives you more flexibility and makes your muscles warm so that you could pull off moves that you normally can't every day.
It's important to stretch all parts of your body, not just your legs. Fencing uses all muscle and tendon groups; from your pinky finger to your baby toe.
Be sure to stretch your hands an wrists, torso, legs, and toes.
Not doing this is bad for your body an results in painful muscle strains if not more serious torn muscles or ligaments. So take the time to stretch. It'll make your body happy and you won't be suffering from strained muscles.