The single best exercise for lower-back stiffness isn't a stretch — it’s this 2-step back and core move

Back pain doesn't always originate from your back. For example, tight or weak hips, core muscles, or glutes can cause lower back pain or stiffness, and your back muscles may under- or overfire if you don't focus on proper posture.That's why exercises that strengthen the muscles around your spine and pelvis, like your core, hips and back, are crucial — it's not just about stretching. There's a specific two-step exercise tucked neatly away that I like to bring out for this exact moment. It's technically two moves — one for your posterior chain (your back, glutes and hamstrings) and one for your deep core; together, they can strengthen your postural muscles and reduce pain and stiffness.It gets met with a groan every time I introduce it to my clients' sessions, but if you suffer from a tight lower body or symptoms of sciatica, this could help. How to do the exercise in two steps(Image credit: Shutterstock)Start on your back with your arms and legs extendedEngage your core and curl your hips toward you so that your back is supported by the matLift your legs to hover a few inches above the mat, then crunch through your abs and lift your arms and upper back away from the matKeep your chin tucked and gaze forward, and focus on breathingHold the position for 30 seconds.(Image credit: Shutterstock)Maintain the position and slowly roll onto your stomach so that your arms, chest and legs are lifted away from the matKeep your gaze down, neck neutralSqueeze your shoulders, back and glutes as you lift through your chest and thighsHold the position for 30 seconds. Roll onto your front and repeat the steps above several times through. I recommend between 3-4 sets.If you struggle with the intensity, reduce the time spent in each position by 10 seconds and try again. Focus on squeezing through your core as you face upward (known as the hollow hold exercise), then squeeze your back and glutes when you are in the prone position (face down, known as the Superman exercise).You can softly bend your knees if you need to, but otherwise, try to keep your legs straight and toes pointed in both positions. Once you feel comfortable, try adding a gentle rocking motion, a bit like a rocking horse, to the hollow hold.It's crucial to breathe during exercise, which might sound obvious, but a surprising number of us hold our breath when the body is under stress or strain.It's crucial to breathe during exercise, which might sound obvious, but a surprising number of us hold our breath when the body is under stress or strain. During workouts, breathing helps regulate blood pressure; did you know your diaphragm also counts as a core muscle? Expansive breathing helps keep your core engaged and posture in check, while diaphragmatic breathing in general is known to help reduce stress.Focus on generating most of the movement in your Superman position from your mid to upper back rather than excessively arching your lower back, creating a soft banana shape with your body. Switching on your glutes will also help protect your spine as you lift your legs into the air.It can feel mentally and physically challenging, but done regularly, the two exercises combined can counteract weak postural muscles, which are a negative result of sedentary lifestyles.Take long, deep breaths and use your exhale to deepen the pose and lift higher. More from Tom's GuideForget planks — I did 100 sphinx push-ups every day for a week, and here are my resultsI drank the same smoothie as Tom Brady every morning for a week — here’s what happened to my bodyForget squats — you only need 1 dumbbell and 5 exercises for this full-body workout