A strong core is the secret to improved triathlon technique, stamina, efficiency and injury prevention. Here are four key at-home core exercises for triathlon to gain real inner strength.

Achieving the lean, ripped torso of a pro triathlete might not be achievable for many of us, but any triathlete can build the deeper core strength that helps hone swimming, cycling and running technique, reduces wasted energy and decreases the risk of injury. These four simple core exercises for triathlon – complete with progression ideas – can be performed anywhere with no equipment and will quickly make a big difference.

What is your core?

Often thought of as purely the abdominal muscles, the core is made up of all the big and small muscles around the midsection and pelvis.

These core muscles function to stabilise the body and shift force between the arms and legs. Having a strong core means you can utilise this and more effectively transfer strength between the lower and upper body as well as reducing the risk of injury particularly in the lower back, which is often overused when the core is weak.

Why is core strength important for triathletes?

Swimming, cycling and running are all sports that use the whole body and depend on the core as the foundation to support their movements. As such, core strength is essential for any triathlon competitor.

During swimming, a solid core helps to provide a good body position throughout the stroke, aiding in good rotation and connecting the leg kick and arm stroke. A weaker core can often result in fishtailing, where the legs waft around from side to side in the water, reducing streamlining and requiring extra energy to correct.

Of the three triathlon sports, cycling is the least dependent on core strength, however, it’s still important to avoid wasted energy and comes into its own when climbing and particularly when getting out the saddle. A strong core also helps transfer more power through the legs and stabilises the body position on the saddle.

core strength is essential for any triathlon competitor

When running, a strong core is important for maintaining good form over time and helps with posture, stability and control. A weaker core disconnects the upper and lower body, sapping energy, which can result in a rocking or twisting motion between chest and legs. A weak core also means you’re more likely to drop the hip and knee in the recovery leg, resulting in the supporting knee having to counterbalance and folding marginally inwards, creating an injury risk.

Technique, engagement and breathing

Correct technique is of the utmost importance when performing your core exercises – quality is certainly more important than quantity and will help reduce the chances of injury.

Before performing your core exercises it’s important to engage your core first. To do this simply breathe in and then as you breathe out draw your belly button back towards your spine – you should now feel your core engaged! Ensure you keep this engagement throughout the exercises, particularly the ones that require movement. If you feel your core disengaging, take a pause, engage your core and try again.

Deep, controlled breathing is also essential while doing your exercises, so avoid the temptation to hold your breath during movements, which causes unwanted tension.

How often should you do core training?

As with all training, start with the basics and progress gradually. Aim to complete these core exercises for triathlon three times a week running through each exercise two or three times. If you struggle to fit in specific core sessions, try tacking it on to the end of one of your low-intensity sessions as part of your stretching routine.

4 key core exercises for triathlon


The plank is a very simple and functional exercise that works on the whole of the core improving core strength, stability and posture.

Core Exercises For Triathlon - Plank
You may find the plank challenging to begin with but persevere and you will soon become a stronger triathlete. (Photo: Triathlon Vibe)

The plank is a static exercise where you hold your position and form to improve your core. You should feel the muscles around your mid-section working, they may even start to shake.

How to do a plank

On the floor, start in a pushup position but with your elbows bent at 90 degrees under your shoulders with your forearms resting on the floor. Ensure your shoulders are relaxed. Your torso should be off the ground with your forearms and toes as points of contact.

If you’re new to core exercises you may want to start with your knees on the floor helping ensure correct technique whilst you build up your core strength. Ensure that your shoulders, hips and ankles form a straight line. It can be very tempting to push your bum in the air – making the exercise less effective – or to drop your hips, which isn’t good for your lower back.

Gradually work your way to holding the plank for two minutes, once you have reached this it is time to mix it up.

Plank progressions

While performing the plank, you can make your stabilising muscles work harder by removing one of the points of contact. Lift a leg or arm off the ground, concentrating on maintaining your stability and alignment through the body. As your core strength improves, you may progress to raising the opposite arm and leg at the same time.

Another way to make the plank harder is to gradually raise the starting position of your feet. You can even try placing your feet on more unstable surfaces such as a couple of cushions or a swiss ball.

Side plank

The side plank focuses on the supporting core muscles that often get missed. In addition to your core, it also works on your shoulder and hip strength and stability too.

Core Exercises For Triathlon - Side Plank
Strengthing the core isn’t all about rock hard abs – you need to work on all the core muscles by including exercises such as the side plank. (Photo: Triathlon Vibe)

The side plank should be felt in your mid-section and more along the sides of your ribs than the regular plank.

How to do a side plank

Lying on your side with feet stacked on top of one another, rest on your forearm with your elbow below your shoulder. Engage your core and raise your hips off the ground until they form the central point in a straight line between your chest and feet, aligning shoulders, hips and ankles.

Some people find that raising their non-weight bearing arm skywards and turning the head to focus on it helps with balance, while for others this seems to decrease balance and give a harder workout so try both and see what works for you.

As with the plank, if you’re new to this exercise then you can work up to full weight bearing by bending the knees at 90 degrees so that your lower legs are tucked out the way behind you. If you find your shoulder is taking too much of the load then try putting your elbow up on a raised surface and progress gradually to the floor, allowing the shoulder time to strengthen.

Aim to progress the time you can side plank to one minute each side before progressing.

Side plank progressions

Side planks should always be done in pairs, making sure you strengthen one side and then the other evenly. You can progress this into one movement, transitioning directly from one side to another by rolling into a normal plank position then up onto your other side without relaxing to the floor.

Another way to progress is to adopt the side plank position then raise your top leg upwards until you reach the end of your range of movement. This gives the glutes an extra workout and also makes maintaining balance harder, forcing stabilising muscles to become more active.

Glute bridge

Thanks to sedentary office jobs where we sit all day, many of us have lazy glutes which the body compensates for with an overactive lower back. So, as well as working the core, this glute bridge exercise strengthens the glutes to reduce the load on the back.

Core Exercises For Triathlon - Glute bridge
Engaging the glutes is key to reducing the load on the lower back and maintaining good form. (Photo: Triathlon Vibe)

When doing this exercise, it’s really important that you feel the work is coming from the glutes. You may need to do some bum squeezes initially to fire the glutes and train your mind to understand what it feels like when your glutes are working.

How to do a glute bridge

Start by lying on your back with your knees bent at 45 degrees, feet flat on the floor and arms raised. From here, engage your core to press your back into the ground. Maintaining this tension, focus on contracting the glutes then push down through your heels whilst raising your hips upwards until they form a central point between knees and shoulders – or until just before you feel your back trying to take over.

If you find it difficult to maintain balance with arms raised, then place your arms gently on the floor for support – but avoid pressing down while performing the glute bridge.

Aim to perform 20 reps for each set – all with perfect technique. Stop if you lose control of the glutes or if your back starts taking the load instead of the core.

Glute bridge progressions

Once you’ve mastered the glute bridge, you can progress to a single-leg version, raising one heel from the ground and ensuring you still maintain stability and control. This will isolate the muscle, forcing it to do all the work and making the exercise harder.

As with the plank, you can make the glute bridge more challenging by starting with your legs in a higher position, such as on a bench or sofa and build gradually towards an unstable surface like a swiss ball.

Superman on all fours

This exercise focuses on keeping your trunk strong while extending your extremities – which is exactly what we do in swimming, cycling and running.

Core Exercises For Triathlon - Glute bridge
The Superman on all fours requires balance and coordination, as well as control – slow and steady provides a better core workout. (Photo: Triathlon Vibe)

Superman on all fours works the core as well as smaller stabilising muscles around the hips and shoulders. The key to this exercise is to move slowly and keep control of your movements.

How to do a superman

Start on all fours with your knees below your hips, your hands below your shoulders and your back flat. Engage your core then slowly extend your opposite arm and leg out in front and behind you respectively. When raising the leg, squeeze the glute to avoid the work being transferred to the lower back. Once full extension is reached, bring your arm and leg back to the starting point in a slow, controlled manner before switching to the other side.

Aim to perform 20 reps – 10 on each side.

Superman progressions

To progress this exercise, instead of bringing your arms and legs back to their all-fours starting position after full extension, continue to draw your elbow and knee together, pulling the abdominals into a crunched position to make the core work harder before extending back out. You can also amplify the workout by performing all the reps on one side before swapping to the other.