The secret to training your abs is out – and it entails more than sit-ups and planks, more than just targeting your rectus abdominis, the ballyhooed band of muscle between your chest and your hips. If you want true core strength, a growing group of experts will tell you that you need to carry heavy weights and walk. This forces your core to constantly microcorrect and rebalance as you move, explains Aaron Horschig, C.S.C.S., D.P.T., a St. Louis-based physical therapist. You also need to twist and turn, challenging your oblique muscles and back extensors.

‘While there’s nothing wrong with training the abs for show, training for stability – which encompasses all of the muscles that surround the spine and hips – is essential training for everyone,’ says Horschig. His new book, Rebuilding Milo, includes a variety of exercises, many of which challenge your entire core – think lower back extensors, glutes, and obliques, which all team up with your abs to stabilise and bolster your back, lending postural support.

Unlike body parts that handle just one or two tasks (like your biceps, which are most heavily utilised to bend your elbows), all those core muscles have a host of responsibilities. They work together to flex your spine (as happens during a classic sit-up), and they help rotate your shoulders so you can turn to look at a friend. They also prevent excessive rounding of the lower back (known as anti-flexion), a key tactic in the battle to stop back pain. The ideal abs regimen trains all these functions, protecting you against injuries and readying your core (and spine) for anything life can throw at you. Horschig says people finally get that. ‘More and more people are starting to understand the true role of core,’ he says.

The end result of all this work? A lower back that’s armour-plated against persistent pain, and the ability to move athletically and fluidly. And along the way, you’ll build those six-pack abs, too.

Train your abs every day. Some muscle groups require several days to recover, but your core muscles are built to be resilient. That means you can train them nearly every day. Consider doing 3 or 4 sets of core work in every workout, rotating in new and different ab exercises to continually challenge your rectus abdominis, oblique muscles, and lower-back spinal erectors.

Never going heavy. Bodyweight planks and sit-ups are a solid starting point for your ab training. But just like any other muscle, core muscles are meant to be loaded and overloaded. Add resistance to your core training, and don’t be afraid to challenge yourself, especially on moves like the mixed-rack carry. ‘You have to do that sometimes,’ says the popular bodybuilder and trainer known as Ulisses Jr. ‘I’d be lying if I told you I didn’t load my abs.’