An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
The first law is, perhaps, the most readily observable on the soccer field. A player already in motion will more easily continue to be in motion and be able to "spring" into action in response to events on the playing field. A player who is stationary will have a more difficult time responding to the soccer ball. The basic lesson here is that players will do better by staying in motion on the soccer field as much as possible. The best world class players are always on their toes . . . even when they don't have the ball.
For general health and fitness purposes, being in frequent motion (rather than sedentary practices) is essential for building a healthy lifestyle. If you sit around, your body will accommodate sitting around. If you stay active, your body will embrace and accept active lifestyles.
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
Force = Mass x Acceleration
For every action, there is an equal and opposite reaction.