Pablo, you must be able to touch the brakes immediately when you taxy. On the take-off run, you must not be touching the brake at all. If you have a crosswind on takeoff with a lot of rudder pushed on, there is a danger you may press that toe brake. So you must have both heels on the floor for take-off. I have had a take-off abandoned in a 4 engine jet because the other pilot was pushing a rudder pedal hard and had pressed the brake too. It is easy to do.
Your English is better than our Spanish!