Islam governs all aspects of life and has a stance on any topic that you could imagine. Of course, our main focus as Muslims is to be close to God. We are put on this Earth as a test for the Hereafter. What we do in this life will be assessed in the Hereafter. This does not mean that we have to live a life of strictly praying and pure spirituality. Instead, there needs to be a balance. God does not want you to sit around all day, everyday, and only pray and recite Dua (supplication) to Him. He wants you to think about Him in everything that you do everyday, but that does not mean do nothing else. Physical appearance is important. Maintaining your health is important.
Islam is not just about spiritually but it is also about health and happiness. Being physically active is important, because if you are allowing yourself to become overweight or unhealthy, that behavior is frowned upon by God. He gave you this body so that you would take care of it, and only allow good and pure things to go into it. He did not give you a body to put haram (forbidden) food or drink into it. We must do whatever it is in our power to keep our body healthy and fit.
God tells us that we are put on Earth to build for the Hereafter. So use the resources around you to do so. It is important that we take the share from this life that God has given us, to show Him that we are thankful for what He has given us. When you are healthy you can maximize your energy to build your life for the Hereafter. It is recommended that you should play sports or engage in other physical activities, as it is good for your soul to be focused on maintaining a healthy lifestyle.