Well having about 8 years of boxing training along with about as much wrestling, being a Scorpio with Capricorn ascendant, moon in Leo, Mercury and Venus also in Scorpio. I would have to say for having such a heavily fixed chart I am pretty well tried, tested, and proven. I believe it depends on will power, emotional control, and skill. Cardinal signs Capricorn, Aries, Cancer, and Libra are known to be the most likely to excel in military and combat sports because of their initiating nature. Me being a fixed sun, moon, mercury, and Venus definitely adds staying power. A tremendous will. And stubborn as hell. Just look at the fixed and stubborn nature of a Taurus. Whenever cardinal (also Martian and Plutonian) energy is found, will be a fighting spirit and a metaphorical kick in the a** for the placements inhabitants. Fixed signs have strong wills and often have a hard time letting go of anything they are truly passionate about. Whatever that may be.