The Bible expects every believer to honor their bodies with God. (1 Cor 6:20) I've noticed that a possibly common issue that pops out of the minds of brethren is to do good things to our bodies. Reasonably, we could conclude that God really loves us so much that He would like for us to be always healthy. I don't think this is always the case though and can really throw a lot of people off. For example, why do we have viruses and bacteria that makes our loved ones sick? The interpretation should instead be to follow God's standard because believers have been bought with the blood of Christ. The Bible sees our bodies as temples, and we should abide by the Word of God. I see it as putting our mind on heaven. Just think of it, how would people react once they are exposed of their foolish desires and how selfish it was? A friend of mine wants to be a fitness model to get all the girls. His dad, having been in the business, keeps advising his son to give it up out of concern for being bottled up in empty relationships- money is also a major factor that motivates a lot of intelligent people.
Being sick could also serve as a purpose of reminding us of how the world is filled with pain and until the coming of Jesus, we will be struggling under our sins. I myself have been enjoying communicating through writing and personally preaching to myself. Even with this benefit I have obtainable, I still struggle with the fact of how I wish I was taller, had more muscles, and more hair! I feel a little locked up because I can't find this absolutely satisfying reason in the Bible to exercise and put on Rogaine for gaining some benefits. The Bible definitely has its mind on Christ and won't be appeasing to any reader's selfish desires.
God states that we were all made in the likeness of Him and in Psalm 139:14, we were naturally born with beauty. Being a young guy still, I can still obtain these physical benefits to increase my confidence in myself. The question that's been a little headache is if I obtain big muscles, for instance, will I turn into an arrogant and conceited person? First off, the heart has to be right with God. Secondly, we should be doing all we can to serve under the influence of the Holy Spirit. This means being active in Bible study and obtaining wise teaching from anointed individuals. We must be doers of the Word, not just bench-warmers! (James 1:22)
A suggestion I have received from google searching is that if too much Bible study makes you backslide then get a hobby! We each have a certain threshold of faith, and God molds us individually with different trials. We all belong to the same body, even though we are different parts, we are all spiritually equal. Surely, one could do more but it's not by works we are saved! (Ephesians 2:8-9) It is a true blessing to walk with the Lord, and we should invest some time to increase our faith in Jesus. As one gets closer to the full counsel of God, he or she becomes more like Jesus in the Spirit! It is a satisfying journey to serve the Lord and to cast my eyes primarily on Him. Too often, I have been seeking for the approval of others and as a result, brought down. Anyone who has been away from fellowship could detail how Jesus is portrayed as peaceful man by turning the other cheek! John 5:22 states Jesus is the judge in heaven. We should keep in mind many do feel hell should be a logical place. I know this may be a little hard, but we should pray for those who wrong us to have a relationship with Jesus. Pastor Bob Coy of Calvary Fort Lauderdale said "Hell is a logical place." Raul Reece of Calvary Diamond Bar said it's a place of grinding of teeth (imagine slowly and painfully losing an inch off your vertical teeth length) and burning - so painful that only demons deserve to live there. Oh yeah, God totally deserves to be revered. Evaded the topic a little to discuss about God's undivided attention, but getting back!
My take about exercising or improving our appearances is fine, as long as it does not contradict the Bible. I think whatever could be done naturally without harming ourselves fits God's boundaries. Proverbs 16:24 describes the Word of God, "Pleasant words are like a honeycomb, sweetness to the soul and health to the bones." Jesus gave permission in the gospels to visit the doctor if we get sick. (Matthew 9:12, Mark 2:17, Luke 5:31). 3 John 2 states that John wishes the elders to be in good health and to prosper in all things. Isaiah 6:10 and Proverbs 3:8 imply being lazy is a sin and producing fruitful labor in body comes after a literally physical transformation in the individual's actions that comes from the heart's attitude, which gives a definition of repentance. Keep in mind, the Biblical context shows that the men of Israel were called by God to train themselves to defend their nation during the times of war.