If you want to learn how to develop the four basic punches in boxing: the jab, the cross, the hook, and the uppercut, those can be learned fairly quickly. The strategy of boxing an opponent takes longer. This is also true for other "hard" martial arts including karate and kung fu.
Unlike these "hard" martial arts, Spring Power does not teach you how to hit or kick your opponent. The basic premise of self defense in Spring Power is to touch the opponent as lightly as possible, immediately control their balance and then drop them on their head. If you can do this then you have a lot of options as to how lethal you want to be. This level of boxing takes a very long time to learn. Spring Power self defense teaches that you are not a battering ram but a spring mechanism.
These principles hold true for any "contact" sport including football. An offensive or defensive lineman learning these principles would dominate their opponents.