If Christ dwells in our body, how much care of our body should we take regarding smoking or exercise?
The Bible instructs believers to treat our body with respect knowing that it is the dwelling place of the Spirit:
Paul's principle concern was avoiding sexual immorality, which desecrates our physical body. Instead, we should live in such a way that we glorify the Lord with our body. In matters of food or drink (or by extension, anything else we put in our bodies), we have liberty:
Nevertheless, if our choices bring discredit on Jesus or call into question our witness, then we should abstain from such things:
So there are no specific set of rules for how a Christian should care for the physical body other than do not sin with your body nor cause others to sin by your example.