Core Exercises The “Core” ExercisesThis IronGlenn Exercise Set plus his “Circle of Balance” provide a unique and powerful training regimen for the serious athlete. The Core exercise group is for all players to strengthen and protect the athletes body.. The Core Strength A Strength B Pitchers Stride Batters Catchers Glutes Infielders Outfielders Shoulder The Core Strength A Strength B Pitchers Stride Batters Catchers Glutes Infielders Outfielders Shoulder Core Exercises