One activity that i do in order to stay in shape when not in wrestling season is lift weights. Lifting actually involves quite a bit of physics. For example when you use the bench press you need to apply a force on the bar to push up the bar and the weights that are on it. The amount of force you exert on the bar is the same amount the bar exerts on you. Also, the reason for why the weights feel heavy is from gravitational force pulling the weights downward at an acceleration of 9.81 m/s^2. In all essence all bench pressing is, is exerting a force on the bar and it exerting that same force on you. Another example of physics in lifting can be seen when you dead lift. When you squat while holding the bar, gravity is pulling you down. The opposite force to make this balance is the normal force which the ground exerts on you and the extra weight you are holding. The normal force balances it so the net force is 0, keeping us in place while we lift. Overall you can find physics in any type of lifting exercise you do and these two good examples.