A good standard of fitness in airsoft will certainly help you to win games. There are many people who are concerned that they might be too unfit to play airsoft, but this is not the case. If you are struggling to keep up then you can always decide to hang back and defend a static position, or in the worst case scenario you can drop out of play for as long as you want to and take a breather in the safe zone. Plenty of unfit people come to games and of course they are improving their health every time they do so, even more so if they push themselves, so poor personal fitness isn’t something which should discourage you from coming along.