If you play sports a lot or competively then most likely you stay active and are in at least decent shape. I'm going to give a list of certain exercises you should do to better your performance in your sport of choice.
Football: If you play football you need lots of lower and upper body strength. Squats, dead lifts, and bench presses should be the staple of your workout routines. Squats are great for strengthening the legs and tremendously increase your over all power that you need to make tackles, blocks etc. Dead lifts are also very great for building over all strength. Dead lifts will help tremendously with pulling power and grip strength. Bench presses are obviously the best over all upper body strength builder. You need strong shoulders and chest as well when trying to tackle, resist being tackled, or to make a great block.