A strong core isn't about having photogenic abs, looking good in swimwear or grinding out another deadlift. It is a key element in dozens of everyday movements, including simple things such as carrying your shopping or getting out of bed in the morning. Many people know that a weak core can lead to a bad back, but the benefits of strengthening it are sometimes underappreciated. An analysis of studies published between 1970 and 2011, for instance, found that "core stability exercise was better than general exercise for reducing pain " in chronic low back pain patients. Given that back pain affects 540 million people globally, just five or 10 minutes a few times a week spent improving core strength is an excellent investment.
The big three
Spine researcher Dr Stuart McGill at the University of Waterloo in Canada has spent his career studying back pain and its rehabilitation. He recommends a "big three" set of exercises. This consists of the curl-up, the bird dog (or quadruped) and the side bridge, all of which are low-intensity and suitable for almost everyone.
Do it right
Gyms usually offer short core-strength classes. Even if you much prefer exercising at home, it is always a good idea to make sure you are doing exercises correctly to avoid injury. Fitness apps such as Gixo and TrueBe use your smartphone camera to connect you to a trainer, so you can also have a one-off or "booster" PT session at home.
Don't stop when pregnant
Pregnancy and childbirth can be particularly challenging for the core - studies suggest 50 per cent of pregnant women will have low back pain, while 20 per cent will have pelvic girdle pain. An analysis in 2013 reported that five of the seven studies examined showed significant reduction in intensity and presence of pain in pregnant women undergoing an appropriate core-strengthening programme.
Crunches and sit-ups were once the go-to core exercise for gymgoers and fitness routines. But these exercises are now thought to be quite hard on your back and to isolate muscles that would be better exercised in combination. Plank exercises - and other more dynamic movements - use more muscles at the front, side and back of your core. There are many different varieties, starting with the simple half plank - on your forearms and knees, rather than toes, maintaining a straight back. Longer is not always better: good form maintained for a small time is much better than bad form dragged out for minutes.
Dead bugs are one of the simplest and most effective core exercises. Lie on your back with your arms extended, knees bent at 90 degrees, calves parallel to the floor. Keeping your lower back in contact with the floor, extend and lower your left leg and bring your right arm up. Tap your heel to the floor, return to the start and repeat with the opposite arm and leg, making sure your lower back never arches.
Variety is key
Mixing it up is crucial, as is focusing on trying to keep your deepest abdominal muscles "engaged" - they are the ones you will feel when you cough. To add difficulty to a home routine, consider a TRX suspension trainer or a Swiss ball. These add a stability challenge to standard exercises. Others swear by pilates - although a Cochrane review suggested that, while it is effective, it is no more so than others form of exercise for pain and disability.