Variety is good but pushups are a fantastic core exercise. They really workout much more than your arms and you can do them anywhere. Plus, these workouts do

Variety is good but pushups are a fantastic core exercise. They really workout much more than your arms and you can do them anywhere. Plus, these workouts do build up a certain amount of aerobic value because they involve multiple sets with shorts rests in between. I'm up to 75! But best to also do some squats, some situps/crunches, etc.