Thanks for the email. I keep in good shape by making it a priority in my life.
I schedule time each day to work on my fitness, soccer skills, strength, etc. so I can be the best player I can possibly be. I also play lots of other sports and do lots of other activities to not only keep fit, but to have fun.
I believe physical fitness is important because it forces us to test our mental and physical strength and gives us an immediate gauge on what we are made of... meaning do I give up (am I a quitter) or do I finish the job and rise to the challenge? When we constantly are able to meet the challenge physically by being mentally tough, then our confidence increases and we become tougher and stronger on the inside, too.
Hope that is what you are looking for.