What stroke should you swim in a open water swimming event?

There are four official swimming strokes: Front crawl, Back crawl, Breaststroke and Butterfly.

Front crawl is generally the preferred stroke for open water swimming as it has the least resistance in choppy water. It is generally the fastest stroke and is used by elite open water swimmers. Breathing can be on either side, which can be useful if there are waves coming from one side.

Breaststroke is preferred by some people who dislike their head going under water, you can also see which direction you are swimming as you breathe, and it is often the only stroke some people have learnt. However the stroke has a lot of resistance when swimming, some find breaststroke hard on the knees over a long distance, if you are wearing a wetsuit your legs can float too high for an efficient kick, and if it is choppy water you can get a mouth full of water when you breathe.

Backstroke isn’t recommended in open water as you can’t see where you are swimming and you may end up swimming into other swimmers.

Butterfly over a long distance is only undertaken occasionally by a very experienced swimmer. In a mass event butterfly swimmers need to be careful of other swimmers around them as the arms tend to fling wide with this stroke.


Swimming is a low impact sport, as it is non weight bearing. This is good news as you are less likely to pick up an injury compared to other sports.

You should not enter your first open water event without having swum previously in the outdoors, regardless of whether you will be swimming in a wetsuit or not. Start off gradually and build up your distance.

You should swim at least two times a week and ideally three (one of these should be outdoors where possible).

To train for an open water swim, you need to think about two aspects of the event.

1. Being swim fit: The easiest way to become swim fit is to regularly use a swimming pool or lido.
2. Being acclimatised to swimming outdoors: On the event day it could be cold or a bright sunny day, and the water could be calm or choppy. You should be comfortable swimming in all conditions. It is very different swimming outdoors compared to swimming in a pool. There is no black line on the bottom of the lake to follow, the water may not be as clear, and you must look up to see which direction you need to swim.

Pool Training

One mile in a pool = 64 lengths of a 25 metre pool.

Find out if there are any adult swimming sessions in your pool, perhaps a triathlon club or ‘Masters’ training session. These sessions are often welcoming and a great way to improve quickly. Often they have a swimming coach on the pool side to provide set sessions for you and can help with your technique.

A swimming session should consist of a Warm up, Main Set, Contrast Set and Warm Down:

Warm up: Gradually warm up your arms and lungs as you increase your pace over some short distances.
Main Set: Typically a target distance broken down into shorter distances with short recovery times to help you work on your pace. For example: the target may be 1000 metres, so a simple session would be to swim 10 x 100 metres with 1 minute rest between each 4 lengths (in a 25 m pool). This way you can swim faster for the duration of the 100 metres than you would be able to over a straight 1000m swim.
Contrast Set: After a main session the contrast set throws in some drills with perhaps some kick or stroke work.
Warm down: a reverse of the Warm up, reduce your speed and think about technique.

Other times you may go into the pool to complete a long distance swim, for example, to swim 1 mile non stop and time yourself.

Sample main sets:
Big Step Pyramid (1150 metres)
25 metres, (5 sec rest), 50 metres (10 sec rest), 100 metres (15 seconds rest), 200 metres (20 sec rest) 400 metres (30 sec rest), 200 metres (20 seconds rest), 100 metres 15 sec rest, 50 metres (10 sec rest) & 25 metres = 1150

Build Set (1475 metres)
25 metres (5 sec rest), 50 metres (10 sec rest) 100 metres (15 Sec rest), 150 metres (20 sec rest), 200 metres (25 sec rest), 250 metres (30 sec rest), 300 metres (35 sec rest), 350 metres (40 sec rest), 400 metres (45 sec rest)

5 x 400m (2000 metres)
made up of:
16 x 25 metres (5 sec rest each length) + 30 seconds end of set
8 x 50 metres (10 sec rest after each 50m) + 30 seconds end of set
4 x 100 metres (15 sec rest after each 100m) + 30 seconds end of set
2 x 200 metres (30 sec rest between 200 m) + 30 sec rest end of set
1 x 400 metres

Sample Contrast Set:

8 x 50 metres kick using a kick board
Then 8 x 50 metres (25 metres drill* & 25 metres swim)

*A drill is where you practise one part of a stroke.

Sample Basic Drills:

• Single arm swim. Hold one arm out in front of you and swim only using the other arm. Think about getting a good pull through the water each stroke. Alternate this drill.
• 6 arm switch. Six single arm strokes on one side, then six on the other. Aim: same as above but use hips when switching from one arm to the other to create a body roll.
• Catch up – one hand is always in the water out in front of you. The ‘glide hand’ in the water stays there until the ‘moving hand’ touches the water, then they switch. This is good for lengthening your stroke for long distance swimming. It should be nice and smooth as you always maintain one hand stretch out in front of you.
• Chicken wing – As you swim touch your right thumb under your right arm pit and visa versa. This helps create a high elbow when swimming.
• Three point touch (good for warm up and warm down). Touch three points on each stroke. 1. Catch up as above. 2. Touch your thigh with your thumb, this should be at the end of your stroke a low as you can on your leg without twisting your body. 3. Under your arm pit. With practise this should be nice and smooth and a good way to get your stroke feeling better after a hard session.
• Clenched fist - keep your fist clenched during the whole stroke. Aim: to use your forearm whilst swimming and help appreciate the power your hand creates when pulling through the water. Try and keep this slow and think about keeping a high elbow throughout the stroke.
• Kick on side. Left arm in front of you and on your left side, kick for one length. The change sides. Aim: good to balance in water and getting used to rotating onto your side when swimming.

Open Water Swimming Training

An open water swim training session is typically endurance based, where you swim a suitable distance based on the water temperature. Often open water swim session goals are completing a set distance, getting used to the water temperature, and practising your stroke in varying conditions. As the water temperature increases your distance should increase as well. For each training session keep a log of the distance you have swum, the water temperature and how you felt.

For beginners the ideal water temperature for open water swimming is over 11 degrees, although everyone reacts differently to water temperatures. We suggest using the guidelines below for appropriate distances in different temperatures, but remember everyone is different and you should also taken into account the air temperature and any chill from the wind.

Suggested open water swimming distances and water temperatures
• 11 degrees – 500 metres max swim
• 12 degrees – up to 1000 metres swim
• 13 degrees up to 1600 metres swim
• 14 degrees up to 2000 metres swim
• 15 degrees and over – 2000 metres +

(Only experienced open water swimmers will swim under 15 degrees for any distance without a wetsuit)

During an open water training swim you can also practise the following:

1. Sighting – this is where you lift your head up out of the water to see in which direction you are going. You should be able to lift your head forward and up until your eyes are clear of the water to pick out a point to aim for, such as a marker buoy.
2. Swimming next to other swimmers – By ‘sighting’ and looking at swimmers next to you as you breathe, you should be able to swim without constantly crashing into other swimmers.
3. Swimming around buoys – practise doing right and left hand turns and also U-turns around buoys without slowing down too much.

The basic rules for swimming outdoors are:

1. Don’t forget your common sense! You need to be aware of the safety issues where you choose to swim.
2. Try and find other experienced swimmers in your area, they will be able to advise on good places to swim. You should avoid swimming around places including busy harbours, boating piers, jet ski parks, rivers in flood, man made weirs, canals and fishing areas.
3. Don’t swim alone, swim with others so you can keep an eye on each other.
4. Use a tow-float, this increases your visibility to boat users and other swimmers, if you get cramp you can hold onto it. The are dry bag versions so you can take your car keys or clothes with you.
5. When you find a section of water to swim in, make sure you have a safe place to enter and exit the water.
6. When you start swimming, check to make sure you can easily spot where you started from, this will make it easier when you want to exit the water.
7. Wear a bright coloured hat so you are more visible when swimming.
8. When you go for a swim, make a note of where you have started from, look for land marks that will be visible from the water.