Add some partner training to your workout. Grab a teammate, spouse, your kid, or a friend and challenge each other to a more intense work day.
One of my favorite partner exercises for doubles or a large group is the wheelbarrow and wheelbarrow explosive pushups. Great for relay competitions or for distance or time. From regular pushups to walking or hopping on a flat surface, stairs, or up hill. The wheelbarrow push-up develops upper body strength and explosiveness and will do a number on your core as you fight to stabilize your lower half that is being held by your partner.