I just switched to a new gym, and the young lady who runs it did a body-fat measurement and we found I am at 15.5%, 195 lbs, 5'8", and two weeks shy of 70, resting heart rate 52.
We now are developing a program to enable me to enter (in the senior's division, generally over 40) the 'physique' judging in body-building competitions. This physique judging in the men's body-building is relatively new, and as it gains popularity the age groups should expand into participants closer to my age.
The judging is on appearance and definition, rather than musculature/bulk (The Hulk, Ahnold, etc). I use free weights, and ride a bicycle on the local roads 17 - 25 miles per ride.
edited to add: My gym person warned me that if I do compete, I'll need to drop to about 4 - 5% body fat, while maintaining my weight at 185 - 190, a good weight for me.