With just a little inventive inspiration you may find all sorts of physical activity to keep that razor edge. Try lining your flight bag with lead for weight training. Run up and down the aircraft stairs with it until you bonk. In many third world regions a whole new variety of sporting activities await you. In Asia and South America it is easy to find martial arts training, indeed learning to grapple with two or more partners is a fine skill to hone. Games of stickball with the local youth are good(your head is used as the ball), as is the classic run through the barrio with your Rolex.
For another event, simply refuse to pay your bill at a local "entertainment" facility. The ever willing to please local authorities will introduce you to a game that bears a striking, and I do mean striking, resemblance to indoor Rugby.

The great thing about most of these events is that they have no drab and boring set finish line, but are much more fluid in their conduct. You will find their ways friendly and informal.
Having the crew van hijacked at the point of an automatic rifle will allow you a rapid jump to a 200+ pulse rate and test your reflexes. All in all, I think you will find many of these events so stimulating that you will forget all about tri-gear and concentrate solely on your new found sporting activities.