Open-water swim technique: 11 common mistakes triathletes make

Triathlon swimming coach Annie Hollest explains 11 common mistakes triathletes make in the open-water swim and advice on how to correct them

Credit: James Mitchell

1 Avoiding the plunge

If you’re new to triathlon you’re probably putting off the inevitable, particularly given the low temperatures in the UK this spring. However if you’re entered for triathlon with an open water swim its vital you practice in open water as much as you can prior to race day.


You’ll find the environment completely different…there’s no black line to follow and the water can be murky and cold. The sooner you dive in the better so there are no surprises. If you’re really nervous seek a good local coach or club and sign up for a group beginners’ session – you’ll find many people are feeling just the same as you and its really not as bad as you’re dreading!

2 Leaving Open Water swimming skills practice until the season starts

Did you know there are lots of things you can do in the pool over the winter to keep your open water skills tuned up year round? This includes:

  • Crocodile sighting regularly every odd length of your set.
  • Swim alongside a buddy hi-fiving the arms closest to each other with the lane rope between you. It’s a great drill for practising having a higher swinging arm recovery.
  • In Line (on the toes) or Arrow Head (on the hip) drafting as part of your warm-ups/cool-downs, taking it in turns to lead/follow/left/right hips. This can also improve your confidence swimming in close proximity to other swimmers.
  • Mass starts in the pool with a group of buddies or as part of your club session will help you get used to being around other swimmers in race conditions.

I regularly run a wetsuited open-water session with my squad throughout the winter and spring months. We remove all the lane ropes and secure orange buoys to float over the flags to mark out a rectangular course in the pool, completing clockwise and anticlockwise loops. The squad always surprise themselves with how rusty they get without this regular practice.

3 Not researching the swim race course

Here’s a map of the Blenheim Triathlon Sprint Course (swim course in purple):

The majority of the course is a straight line, following a row of small buoys on your left hand side. There’s a sharp left turn at a larger buoy about 650m, with another 100m to go to the swim exit. So you’ll have one left turn to make over the whole course. Many courses use a rectangular shape, however, this was the course at Zurich Ironman 2015:

So three sides of a square, under a bridge, exit over an island, diagonally cut the square and complete a triangle before exiting after the bridge. An interesting course but it helps to have studied it first! I find it useful to head down to the race the day before and take mental images of the entry and exit points as well as doing a thorough recci of the start and finish, if you’re competitive you’ll want to know where you’re going to line up if it’s a mass start (unlike Zurich and many other Ironmans which let 10 people go every 10 seconds, much safer if you ask me).

4 Having a CO2 freak out

We touched on this in my last article that covered 9 swimming technique mistakes triathletes make. Holding your breath, even momentarily can lead to a build up of carbon dioxide in the blood, leading you to that ‘panic bell’ moment where you’ve reached your lactate threshold and your body says no more. If you’re untrained for endurance swimming or you go out too hard this will happen even faster. We’ve all seen the athlete starting at the front and breastroking after 75m. This is very common and completely avoidable if you practice good exhalation technique.

To exhale properly, after taking a breath in through your mouth, immediately let your face relax, jaw drop and just let the air go without pausing. Any tension in your facial muscles will restrict the airflow, leading to more carbon dioxide storage. (Don’t pretend you’re blowing out candles!)

The aim is to breathe out as much as you can and as relaxed as you can. This helps to replenish a large volume of air every time you breathe and access the lower part of your lungs where the majority of the oxygen and carbon dioxide exchange happens. Whether you favour breathing every two or three strokes, breathe out right from the start of the race and this performance hump will be a part of history.

5 Purposefully not training the leg kick

The classic “I don’t need to use my legs in triathlon swimming to save energy for the bike and run” is so untrue! Neglecting your leg kick is such a common mistake. Partly because it’s easier to swim with a pull buoy (unless you’re Kicktastic) and we’re drawn to things that make our life easier!

Even with a 3:5 wetsuit with more leg buoyancy you’ll still loose speed not kicking at all as your legs fishtail behind you and drag you down, resulting in a net higher energy expenditure to pull them through the water.

Your leg kick in triathlon needs to be sufficiently hard that your legs stay close together, streamlined and not causing drag. If this requires you to kick a little then don’t shy away from it! In a sprint distance you should have enough energy stored in your body to complete it anyway, so a gentle flutter kick won’t have any effect on your bike and run performance.

At longer distances you stand to gain even more from training an efficient leg kick, since you’re swimming for longer periods. But the likelihood is you’re going to be refueling anyway, so even if you do use a little bit of energy it’s minute compared to what you’ll expend and consume on the bike and run.

6 Buying, not training, speed

Yes a good wetsuit can make you faster, probably a maximum of 4-5 seconds per 100m, but think how fast you could be with a solid training program as well; you could double or treble the speed gain! Ensure your training is balanced and reflects your weaknesses as well as your strengths. Neglecting what’s hard won’t serve you well in the long run.

7 Mistrusting the GPS data

Ever looked at your watch after a training session or race and thought “Oh, that was a long course, they must have marked it out wrong!” On very few occasions this does happen, but it’s much more likely that you’re zig zagging off course! An athlete of mine came back from the Olympic Distance World Champs and said “Annie I got a PB!” Obviously I was delighted, but when I asked how far he’d swum he said 1650m! That’s 10% further than he needed to swim, which means his swim time could have been another 10% faster if he’d swum straight!

8 Sighting infrequently

This goes hand in hand with the previous mistake… There’s no denying that you will swim straighter when you sight regularly. Take a test next time you hit the open water. Choose a buoy and swim 15 strokes towards it with your eyes closed, breathe normally but don’t sight. Stop after your 15th stroke; are you where you thought you would be?

The variation of where people end up in relation to the buoy is amazing when I do this at my open water sessions! Many swimmers do swim straight, but when fatigue hits and you forget to sight you’ll be one of the one’s being scooped up by the safety team heading way off course.

When I race I sight every two breaths. As you may have found, often when you sight there’ll be someone’s arm in the way or a wave blocking your view. I find it helps me piece together my bearings and those little image snippets join together in your mind to give you the racing line to the finish.  You can use the mantra: bubble – bubble – breathe – bubble – sight- breathe to help you remember to sight regularly.

9 Sighting: lifting the whole head out of the water

Quite simply the higher you lift your head to sight, the lower your legs will lie in the water, causing drag and slowing you down. Try to do what I call Crocodile Sighting, just press the eyes above the surface. It helps to sight just before taking a breath. If you’re breathing bilaterally (every three strokes) try using this mantra as your hands enter the water: bubble – sight – breathe.

You’ll find it easy to pair your sighting to your second arm entry, just before the breath. Alternatively you can sight between breaths, put your face back in the water and breathe with normal timing, just try to resist the urge to breathe while lifting your eyes forward to keep up your swimming speed you’ve trained so hard for!

10 Following the person in front / Not sighting when drafting

Ever been underprepared and not really known where you’re going in a race? The likelihood is neither does the guy in front! He might be just as lost as you are and sending you both way off course. You might find a pack separates and heads way off course, don’t be tempted to join them, stick to the racing line.

If you’re drafting on the toes make sure you sight regularly, if you can’t see the buoy or object you’re sighting peel off to the side every so often to ensure you’re staying on course.

11 Training a smooth arm recovery

Common in pure pool swimmers, the high elbow recovery style won’t serve you so well in the open water. If you’re tight in the upper back and shoulders you’ll find it very hard to achieve in any case. If you experience shoulder strain when swimming in a wetsuit this is likely one of the major culprits (second to thumb first hand entry).

Elite open-water swimmers and triathletes opt for a more relaxed straighter arm recovery. It’s not pretty but it works, you’re not getting marks for how aesthetically pleasing your stroke is, just how fast you are! A straighter swinging arm recovery passes slightly higher above the water, which is extremely effective in the choppy open water with other swimmers’ wakes and arms flying around too!

If any of this sounds familiar, let me see if I can help you get more prepared for race day with a private open-water coaching session: