[header] How to build muscle endurance [title] Build strength and endurance together. [step] Typically, at the gym you would do fewer repetitions with heavy weights to build strength, and more repetitions with light weights to build endurance. Doing both together in one routine allows you to build muscle strength, size, and endurance all at the same time. 
[substeps] Design a routine that involves four exercises for each muscle group. Each exercise should target that muscle group in a different way, requiring movement from a different angle, or with different grip positions.