We all know sitting down all day’s not great for our health. But when we recently read the latest news on the setbacks of a sedentary life, we leapt from our seats in horror. A deskbound job, it seems, means a saggy, wide behind.

Scientists at Tel Aviv University recently scanned the buttocks of a group of inactive people and found their muscles to be shrinking and breaking down as a result of underuse. They also found inactivity lets fat cells thrive, causing thick layers of fat to develop deep within the buttock muscles.

And it’s not just the inactivity that’s to blame. The study revealed ‘preadipocyte cells’ (the precursor to fat cells) that were subject to sustained loading – in other words, being sat on – turned into fat cells and started to accumulate fat twice as fast as normal cells. Sitting for long periods won’t just waste your glutes and make your bum fat – it’ll make it flatter and wider, too.

But while our bottoms take the brunt, office work has other body consequences. There’s that hunched-over-your-PC posture and slack abs, for a start. Thankfully, all it takes is awareness and the right exercises to counteract the damage. Here, our experts take you through the causes and corrections of ‘office body’.

The problem: Flabby bottom

“If you’re in a sitting position all day, your buttock muscles – your gluteus maximus, gluteus medius and gluteus minimus – will be stretched out to full range,” says physiotherapist Elizabeth Ebelthite, director of Marple Physio (www.marplephysio.com). “They become lazy and weak. At the same time your hip flexors, at the front of your hips, are shortened and become tight and overactive. Our muscles are strongest at mid range – neither too flexed or too stretched.”

Why does it matter? “Having weak glutes and tight hip flexors can predispose you to lower back pain and hamstring injuries as you’ll overuse these parts to make the movements your glutes should be responsible for,” says Ebelthite. The three glute muscles are also what give your derriere shape and tone, so if you want a bum that’s more fab than flab, you’d better start working it.

“You’re guaranteed to improve sports performance if you target these key muscles, too,” adds Ebelthite. “If more runners worked on their glutes, for example, they’d be stronger, faster and less injury-prone.”

Test your glutes by lying face down on the floor, she advises. “Bend one knee to a right angle, so your sole is facing the ceiling. Keeping the foot flat, slowly raise that leg about six inches from the floor and try to hold it there for 30 seconds.”

If your buttock muscles are strong and switched on, you should be able to perform this move easily and feel it only in those muscles. If they’re weak your leg will start to shake and you’ll feel it in your hamstrings and lower back,” says Ebelthite. “A lot of people just get cramp in their hamstrings instantly, meaning their glutes aren’t firing at all.”

Make it better in the office

  • To strengthen your buttocks at your desk, simple isometric clenches are great – alternate between holding for 10 seconds each rep, squeezing and releasing slowly and fast pulses.
  • Try the Wall Sit. With your back flat against a wall, bend at the knees to lower your body until you’re in a sitting position. Hold for 30 seconds.
  • Take the stairs two at a time to really engage your glutes.

At home or in the gym

  • Lying on your back, feet flat on the floor and close in to your bottom, hug one knee in to your chest. Then try to lift your bottom off the floor a few inches and hold for a few seconds. Do 8 reps, building up to 14.
  • Lie on your side, supporting your head with your hand. Keep your lower leg bent, upper leg straight, foot flexed. Leading with your heel, lift the upper leg slowly and lower. Do three sets of 10.
  • At the gym try weighted squats and lunges, kettle bell swings, the stairclimber.
  • Stretch your hip flexors (after exercise or when warm from a bath). In a lunge position with your back knee on the floor, rest your hands on your front knee, tighten your abs to keep your back straight, rotate your back heel outwards and push your hips forwards. Hold for 20 seconds.

The problem: Upper body hunch

Look around your office and you’ll soon recognise the typical desk-worker slump – shoulders hunched, neck forwards, head dropped. “It’s the opposite of good posture,” says Pilates expert Caron Bosler (www.caronboslerpilates.com). “Your chest muscles (pecs) get short and tight; your upper back and neck muscles (traps and lats) relax too much, over-lengthen and don’t hold the shoulders and head where they should be.”

Why does it matter?

The more time your muscles spend in this underworking, overstretched position, the weaker they get. “A hunchback posture becomes permanent,” says Bosler. “Over time it can actually become impossible to pull the head back into proper alignment.”

Poor posture’s not just unattractive, it can compromise your breathing, circulation, digestion, mood and lead to long-term back problems, headaches, joint problems and more. “Simply by correcting your posture you’ll instantly feel more energised and look 7lbs lighter,” promises Bosler.

Make it better

“Any position that counteracts the forward slump is going to help,” she says. “You need to open up the chest and work the upper back.”

In the office

  • Try the executive stretch – lean backwards in your office chair, stretching your arms out wide to the sides. Relax into the position.
  • Stand with your back against a wall. Try to actively get your heels, hips, shoulders and head back on the wall. Stay and breathe there for a few minutes.
  • Face a wall, just under an arm’s length away. Place your right palm on the wall at shoulder height, keeping a soft elbow. Turn in an anticlockwise direction until you’re facing away from the wall. Feel the stretch across your chest and bicep. Hold for 20 seconds, repeat on the other side.
  • Pretend you’re holding a pencil between your shoulder blades. Roll your shoulders back and down and squeeze them together for 5 -10 seconds. Repeat 10 times.

At home or in the gym

Stand with your feet hip-width apart, exhale and bend forwards from the hips, keeping a flat back. Pretend you’re gathering armfuls of flowers from the floor below you, then lift back up to standing, throwing your arms up and behind you, letting the ‘flowers’ cascade down over your head. “This movement stretches your hamstrings and lower back, then opens out your chest, neck and rotates the shoulders back,” says Bosler.

In a full length mirror, turn sideways. “With correct posture the top of your ear should be in vertical alignment with the middle of your shoulder, your hip, your knee and the point just in front of your ankle bone,” says Bosler. “You shoulder cuff should be pointing directly up, not forwards.”

At the gym, do weights exercises to strengthen your upper back – lat pull-down, pull-ups, bent over row, reverse flies, rowing machine.

The problem: Slack stomach

Ever sit at your desk and wonder what that puffy thing is overhanging your waistband? Wait, no, it can’t be, your… stomach? Yes, sorry folks, but another casualty of the sedentary job is your six-pack. “Sitting at a desk isn’t good for your core,” agrees Bosler. “The erector spinae – the small muscles that run up either side of your spine – have to take responsibility for holding you upright and so they get really tight.”

Why does it matter? As well as an unslightly pot belly, having a weak core can lead to all sorts of lower back niggles and pains, sciatica and referred pain in the limbs and joints. Keep a strong core, however, and you’ll soon have abs to rival Jessica Ennis and posture that makes you look and feel healthy and strong.

Make it better in the office

Switch your office chair for a Fitball. Sitting on one of these means your core is constantly engaged and backpain is minimised. “To pick the right size for you, make sure your hips are above your knees when you sit on it,” Bosler advises. Feels too weird? Just try it for half an hour at a time and build up slowly.

Every time you’re on the phone or whenever you remember, actively engage your core. Think about lifting your pelvic floor and pulling your belly button in towards your spine.

Try Bosler’s top stretch to relieve sciatica: from sitting, cross one foot over the opposite knee, let the knee of the upper leg flop to the side, then lean forwards, feeling a stretch and release around your glute, hip and lower back. Hold for 20 seconds. Repeat on the other side.

Use your desk to perform a half plank. Rest your elbows and forearms on the desk, straighten your legs out behind you and hold, keeping your body in a straight line from head to toe. Aim for one minute.

At home or in the gym

Switch on your abdominal muscles in the morning so you’re more aware of them all day. Do three sets of 10 basic ab curls, keeping a neutral spine throughout.

Work on variations of the plank position, such as side plank or lifting alternate arms and legs (Superman plank).

In the gym, skip the machines and work out using kettle bells, free weights, Vipr, TRX, Fitballs and Bosu boards to add extra core work to your usual routine.