Sunday: Cardio "The perfect cardio for beginners is jogging on the treadmill for 25 minutes," Holly said. "Start with zero incline and get your heart rate up to where it's hard to hold a conversation. The speed should be comfortably challenging." After the first two weeks, try one of these treadmill workouts to kick it up a notch: 25-Minute Walk-Run Workout 20-Minute Beginner Incline Running Workout 20-Minute Fat-Burning Running Workout Image Source: Getty / skynesher