A method is provided for improving athletic performance in a sport in which participants employ a projectile during competition. The method includes training for the sport with a sensing system included in the projectile, where flight characteristics of the projectile remain substantially unchanged with the sensing system included in the projectile relative to the flight characteristics of the projectile as used in competition without the sensing system. The method also includes evaluating at least one flight characteristic measured by the sensing system when the projectile is employed with the sensing system, and if the act of evaluating finds that adjusting at least one physical characteristic of the projectile may assist in improving the participant's performance, changing the at least one physical characteristic.