This content is from the experts at Men's Fitness magazine.
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The Men's Fitness Body Focus workouts target each part of your body in turn. Work your way through the series and you'll develop strength and muscle mass across your body.
The lower back muscle group protects your spine and holds your body in alignment, so a strong lower back protects you against injury and gives you a platform for all-round muscle growth.
How to do this workout
Parts 1 and 2 are designed as separate workouts to be done on different days in your schedule. Leave two or three days between each one to give your back muscles time to recover properly. Warm up for the workouts with ten minutes on a treadmill. Try to spend at least 45 seconds on each set of exercises and rest for one minute between them. Rest for two to three minutes between exercises.