This 7-day cardio plan is a challenge for anyone who wants to test and improve their endurance. It’s a fat burning, heart racing program guaranteed to make you sweat.  There are workouts for all seven consecutive days, alternating between steady-state cardio (running or jogging) and high-intensity interval training. On HIIT days, you’ll be doing up to six moves a day, including squats, burpees, and planks. These moves are great for burning calories and they can boost your metabolism for up to 24 hours afterwards.