He doesn't have to do cardio if he doesn't have too. Have him lift with shorter rest periods with higher reps. Muscles burn more calories this way.
When you look at most sports played today, recreational activities, and work related tasks, the great majority of them place anaerobic demands on the body. Now, surely you have done hard labor before. When performing any intense work, you begin breathing faster and faster…in fact, you will go aerobic within a few minutes if the work efforts demand so much of your anaerobic energy systems that the demand for energy can’t be replaced by intermediate and anaerobic energy systems (fast glycolytic and aerobic).
