This is an absolutely true statement of young men. They are proud that they are strong. Young men will pump iron or exercise to make them even stronger. Paul warns about putting too much emphasis on the bodily exercise.
1 Timothy 4:7-8 Have nothing to do with godless myths and old vives tales; rather, train yourself to be godly. 8For Physical training is of some value, but godliness (spiritual training) has value for all things, holding promise for both the present life and the life to come.
The beautiful grey hair of an old man shows wisdom and experience. For a man to live long enough to have grey hair, God would have to have blessed him.
Under Gods command 