Endurance and Posture: The erector spinae (which literally means spine stiffener) and the stabilizer muscles determine posture and back strength. Having a strong back can help improve your endurance. After-all, if the athlete’s back is tired, chances are there will be a noticeable change in posture which can reduce mechanical efficiency. Furthermore, improved posture allows the athlete stand taller, allowing a better chance to head high balls. Finally, to a much lesser extent, enhanced posture can improve kicking efficiency, making shots and passes more effective and precise.