"Five or six more sets," she gasped as she completed the last five crunches in the latest set. "Are you sure?" Mark gasped. "We had quite the workout." "Absolutely," Sara smirked as she collapsed to the mat to catch her breath. Are you too tired to keep going?" Their workouts always ended with crunches. Sara loved pushing them to absolute exhaustion after their intense sessions. Their sit-ups with feet intertwined and fac...