How long is a swimming pool in the UK?

Before heading to your local pool to get some training in, you may want to find out how long it is (and also what format the pool or swim session is in).

Not only will this help you plan your session more carefully, but it can also help you think about what you want to achieve. But are there standard sizes for swimming pools – and how long are most swimming pools in the UK?

How long is a swimming pool in the UK?

Well, it may not surprise you to hear that just like there are standard distances in other sports – such as in running, where you have standard distances for track and road running – the same is true of swimming.

Governed by FINA, official swimming events are divided into 25m (‘short course’) and 50m (‘long course’), as well as multiples of those distances.

Swimming at the Paralympic and Olympic Games is only contested in a 50m pool, so you will also often hear 50m pools referred to as ‘Olympic pools’.

With this in mind, what size will your local pool be? Most local UK leisure centres will have a 25m pool, on the basis that this takes up less space and is easier to accommodate in most facilities.

So if you are training in a 25m pool for an event that will ultimately be held in a 50m pool, it can be worth thinking a little about the difference it makes – for example try to do multiples of two lengths (50m) but without taking a huge push-off in the middle!

There are many 50m pools in the UK as well, though. These are often based at universities or aquatic centres, which are more set up for competition as well as for training elite athletes.

You may also come across a pool that’s 33.3m (or one which has a movable boom to create this distance). Again, often at universities, these are to create the standard pool size for water polo competitions. Water polo is played across a 30m pool, while the extra 3m is to create the distance at either end between the goals and the pool wall.

There are a few oddities in the UK, too, so you may find smaller or oddly-sized pools on your travels.

Some older pools (such as lidos) may be slightly different (the recently-restored Thames Lido in Reading is 24.68m), while hotel and spa pools are often smaller, too.

Just be aware you might need to adjust your triathlon watch if you’re trying to get some accurate training in!

Which pool size is best to train in?

Most triathletes will be training for a swim from 400m (or shorter) to 3.8km, so it makes sense to train in a bigger pool if you can, as that will have more opportunity to train for endurance, rather than gaining the benefit/rest of reaching the wall and pushing off every 25m.

A good tumble or touch-turn can easily take you 3-5m from the wall, so this is a big benefit if executed every 25m.

A good tip is to note the flags above the lane – they’re usually 5m from the end, so if you’re getting to them with your push-off, that means you are gliding for 10m out of every 25m (allowing a turn at both ends).

You do have to weigh up the added time it may take to travel to a 50m pool if you don’t have one locally, though.

In our book, it’s always best to train local and save the travel time to use for actual training. In these instances, do your pool training in a 25m pool focussing on technique, drills and intervals, and then if you can, do your endurance sessions in open water (when seasonality allows) or visit a 50m pool to practise longer intervals.

You also need to weigh up the timetable the pool offers. Does it have lane swimming times that fit in with your available time to swim?

Plus, are there any double sessions if you need to train for longer than the usual 50-60min swim sessions? It’s no good finding a fantastic pool if the times it is open don’t suit you.

What other features do UK pools have?

As well as obvious things like changing facilities, there are a few other things which may differ in your local swimming pool. Olympic pools will also adhere to a few set criteria from FINA, as well as the 50m length. These are:

1. The pool must be 50m long and 25m wide, so it can be split into eight lanes of 2.5m with 2.5m space either side of the outside lanes.
2. The pool must be at least 2m deep.
3. The water temperature must be kept constant between 25°C and 28°C.
4. The pool must have starting platforms, false start ropes and backstroke turn flags suspended 1.8m above the water surface and 5m away from the wall.
5. The sides of the pool must be flush at both ends.

A note on lanes, too – when taking out a pool membership, ask how many swim lanes they usually have in place. While having lots of access to the pool is great, it can quickly become frustrating (for everyone) if swimmers are training for distance or speed around swimmers who just want to enjoy the water for leisure!

Having separate lanes dedicated to different types of pool user and swim speeds (mostly) solves the problem.

Is there such a thing as a ‘fast’ swimming pool?

Believe it or not, this is a thing, yes! If you’ve ever heard other swimmers talk about a certain pool being ‘fast’ or ‘slow’, it isn’t just in their heads.

Anything that affects water turbulence as you swim will make a difference to how quickly you swim.

This includes things like the type of lane ropes used (the round ones with spinning plastic discs on them absorb turbulence, while simple ropes do not), the depth of the pool and the type of sides (whether water runs off or not).

Top image credit: Robert Daly/Getty Images