It's a bit of a myth really that of the muscular military spy (even James Bond would fit that role) - most intelligence officers tend to be small and wiry, lacking bulky muscles, trained for speed and agility. They would be fit, but not noticeably so. So they of course be lacking beer bellies and man boobs, but they wouldn't have big muscles.
Now someone at DEFCON is not going to be a field agent - they will work in an office behind a computer which leads me to the next myth from DEFCON: that spooks are not geeks. They are exactly that. They are us, like us, have the same interests. They just work against us whilst believing they are working for us.
UKSF are not equivalent to what the American (if I may be so presumptuous) above termed a "Fed" though.
I still largely agree, it's just hard to draw comparisons, although I imagine CID (resp. FBI) personnel even without sidearms may be more naturally inclined to spend time at the gym than the average HN reader.
Now someone at DEFCON is not going to be a field agent - they will work in an office behind a computer which leads me to the next myth from DEFCON: that spooks are not geeks. They are exactly that. They are us, like us, have the same interests. They just work against us whilst believing they are working for us.