This t-shirt is good for three things:
1. Getting a laugh out of anyone who takes the time to read it.
2. Annoying my Krav instructor enough to make me do 20 burpees.
3. Explaining hermeneutics.
Hermeneutics is the practice of using various literary principles to ascertain the true meaning of a written work, in this case scripture. Using the shirt as an example, we see that this is not always as simple as it seems. In fact, scripture can be very easily twisted under the guise of "study".
For a fat guy like me, a Biblical command to avoid exercise would certainly be comforting. Proverbs 28:1, however, is not that. Proverbs as a whole is intended to make the reader stop and think in order to learn wisdom that can be applied to every day life. In and of itself, there is nothing wicked about running when no one is chasing you. However, one of the reasons you might run without being chased is if you have just done something someone might chase you for. Solomon is not talking about a man doing some common exercise routines, but about those who flee the scene of a crime, lest the crime be attributed to them. This is why the same verse continues to say "but the righteous are bold as a lion". The contrast, therefore, is being steadfast in the knowledge that no one has reason to chase you, as opposed to fleeing in fear that someone might.
The shirt, of course, is just a joke, but the principle that makes it possible is the same principle that can be applied to achieve far less amusing ends. Scripture can be twisted in many ways, and unfortunately rather easily. We need to beware, therefore, to first avoid doing this ourselves. It can be tempting to look for comforting verses which, in their correct context, bring no comfort at all, but we should avoid this. But second, beware also that others are guaranteed to try to twist it to deceive you, too. False teachers are all over the world seeking to use your faith to feed their agenda, and the devil is just begging you to listen to them. Don't.