ALL FIT: Episode 6 STRENGTH & ENDURANCE Slim explains that exercise is required to develop strength and endurance. Slim meets Slenda and the All Fit Team at Slim's Gym w... more »here they show exercises to build muscular strength and endurance. Slim points out that different people need different amounts of strength depending on what their lifestyle and activities. In the Body Lab, Slim shows viewers that muscles are made up of thousands of tiny muscle fibers grouped together into motor units. To increase strength and endurance and to make muscles grow, the motor units must be overloaded gradually. Slim teaches the name and location of the Gastrocnemius muscle.« less