"Sporttraining." . . "Isometrie." . . . . "Isometric drills for strength and power in athletics" . . . . . "Leermiddelen (vorm)" . . . . . "Isometric drills for Strength and Power in Athletics" . . . . . . "Sports." . . . . "Krachttraining." . . "Isometric exercise." . . "Gymnastics." . .