How to do sit ups: Form, variations and ab workout tips

The sit-up: a classic exercise we’ve all done, and still one of the best workouts for abs – certainly the most popular. It’s different to the crunch, which is a much smaller movement, designed to work your upper abdominal muscles, but it falls into the same family of simple abs exercises you’ll have likely learned about in PE or gym class. If you want to get more advanced with it, consider looking into some of the best online personal trainer and fitness apps.

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The classic sit up can help in muscular development that contributes to maintaining muscle well into old age. A 2016 study published in Interventional Medicine and Applied Science showed older women with the ability to perform more sit-ups suffered less age-related muscular atrophy, known as sarcopenia, helping them to stay mobile and live longer.

In addition to providing a longer life, situps help athletes and amateur sportspeople alike. A good foundation in sit ups will provide a stronger core, working the rectus abdominis, transverse abdominis, and obliques muscle groups.

If you exercise regularly or play any kind of sport, your body's "trunk" will be twisting and turning, whether carving a wave while surfing or pivoting to kick a football. 

But have we been doing it correctly? Some critics claim sit ups are bad for your hip flexors and lower back, which sometimes take the strain of the move instead of our core. In order to avoid this, we need to learn (or in some cases, re-learn) how to do a sit up with proper form. 

How to do sit ups modified for beginners

Getting the sit up right does require excellent core strength, so beginners should start with the modified sit up. It’s a great alternative to the classic sit-up for those starting out on the road to fitness, or anyone who hasn’t built up their core strength and flexibility. 

Remember to keep your feet grounded throughout and your legs firmly together. The movement should come from your core.

• Lie flat on your back with legs together, bent at the knees, and feet flat on the floor. 
• Place your hands on your shoulders and raise your elbows, so your arms are crossed in front of your body. 
• Raise your upper body until you’re sat upright. Lower yourself back to the start position.

How to do sit ups

If you’ve mastered the modified beginner sit ups, it’s time to try the regular version. Sit ups should be smooth, not awkward, with correct form and technique applied throughout. 

Take your time to begin with – it’s better to do it slowly, with correct technique, than quickly with poor technique.

• Lie flat on your back with your fingertips behind your head, your knees bent, your legs together and your feet flat on the floor. Your elbows should be in line with your ears, or just below.
• Raise your upper body until you’re sat upright, or as close as you can get. As you do the exercise, you should feel your abs tighten.
• Don’t push or pull your head forward while performing the sit-up – your hands and arms should remain still throughout.

How to do sit ups: Common sit up mistakes

Sit ups can be a tricky thing. The traditional sit up can place a lot of pressure on the lower back if you perform the move on a hard surface, as the floor places pressure on the spine as it curves. 

If you do find you're suffering from lower back pain. don't continue to perform sit ups in spite of this, as this could increase your chances of injury. Instead, make sure your exercise programme incorporates moves that tone your core without putting pressure on the spine, such as planks. 

If you do suffer from lower back pain and want to give sit ups a try, consider performing crunches on a stability or swiss ball. According to the American Council of Exercise, a swiss ball supports the curvature of your spine, allowing for a full range of motion while avoiding undue pressure on your lower back.  

Whether you're doing sit ups on a stability ball or on the floor, always focus on form over speed. Lowering your body slowly adds an extra dimension of core strength to the workout. 

Variation: V-up

The V-up adds arm movement for a greater workout. If you’re bored of regular sit-ups, this is an excellent alternative. The V-up is so-called because in the upright position, your body should make a ‘V’ shape.

• Lie flat on your back with arms stretched out behind your head, palms facing upwards. 
• Simultaneously raise your arms, legs and torso, as if you are trying to touch your toes. The movement should come from your trunk. 
• Go back to the starting position and begin the next repetition straight away.

Variation: frog leg sit-up

A frog leg sit-up involves sitting upright as per a classic sit-up, but with your knees bent and splayed out towards the floor.

• Lie flat on the floor with your arms overhead. 
• Feet should be together and close to your groin area, with knees spread wide.
• Using your ab muscles, bring your arms forward and pull yourself up to a seated position. 
• Return to lying and repeat.

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