Explain why exercise programs must increase in difficulty induration overtime to remain effective

Exercise program must increase in difficulty induration overtime to remain effective  because as time goes by our body becomes used to certain physical activites, thus in order to continue to build and maintain the muscle it is necessary to increase the difficulty of your workout

Force and balance. you get agility from balance and the force you use, and leverage can only be attained by using the force to get it. hope that