DIY Swim Sessions

You don’t need to hire a coach to get the most out of swim training. Dan Bullock shows you how to design your perfect swimming session...


You don’t need to hire a coach to get the most out of your swim training. Dan Bullock shows you how to design your perfect pool session


Many triathletes often struggle to construct enjoyable, testing swim sessions that help improve their technique, speed and stamina. While many know the basics – warm-up first, work hard, warm-down – few really know how to put together the sort of varied training sessions that will seem fresh and enjoyable after weeks or months of repetition.   To ensure that your sessions are giving you the best chance of physical improvement – and therefore race success – it’s important to stick to a proven session structure.

Within this framework there are numerous elements that can be switched around and altered, such as drills, sets and exercises. If you do this, your sessions will remain fresh and interesting while maintaining the solid structure required for physical improvement.  I’m going to explain how you can design your own sessions according to ‘best practice’ principles taught by top swim coaches the world over.

Starting point

Typically a 60min swim training session could be broken down as follows. Remember these are just guidelines and can be altered to suit your needs. At a basic level, this is the routine framework around which you should plan your specific sessions.

1 Warm-up This should account for the first 15% of the session, which would work out at around eight or nine minutes. The warm-up should be based around easy swimming to mobilise your muscles and encourage blood flow.

2 First sub-set Around 25% of the session should be devoted to this (15mins). It should be used as an extension of the warm-up to build heart rate (HR) levels or to introduce some skills that need to be practised while ‘fresh’.

3 Main set This is the bulk of your workout, taking up between 40 and 50% of the session (between 25mins and half an hour). This is a
sustained period where your heart rate is elevated. Think of it as the donkey work.

4 Second sub-set This second sub-set is optional and should account for no more than 10% of the session. It’s usually added to start a longer, more technical warm-down depending on the intensity of the main set. Sometimes this second sub-set will be used specifically
for sprint work.

5 Swim-down/cool-down Around five to 10mins of easy swimming at the end of the session is vital to ‘cool down’ the muscles, keep them loose and prevent stiffness. This should take up no more than 10% of the total session time.  

Constructing a session

Using the above structure, there are countless ways of constructing your training sessions. The important thing is to understand the purpose of each element.   The warm-up, for example, often starts on dry land prior to getting in the pool for either a training session or race. Like a warm-up before a run, the idea is to warm and loosen the body ahead of a period of intense activity.

Usually this means an easy swim, predominantly front crawl (FC) or backstroke with some light drills thrown in. Swim aids such as paddles should be avoided due to the increased resistance they provide in the water.   Fly arms and breaststroke kick are also not usually used in the early parts of a warm-up due to the higher intensities they require. While you should be getting your heart rate going, you shouldn’t be pushing it up too far at this point.   Similarly, the swim-down will aid recovery from a tough training session or race. It usually takes the form of a sustained easy swim to help remove the lactic acid build-up in the body, and return HR and rates of breathing back to normal levels. A training session would always finish with a 200-400m cool-down, perhaps longer if the session has been especially intense.

Main sets are the part of the session that concentrates on the focus of the swim training plan, whether that’s endurance, speed, technique or a combination of all three. Exercises will be performed in a number of ways to promote these elements.   There are several training methods that can be used to promote and develop these aspects. While all should not be used in the same session, mixing them up will ensure that your time in the pool is well spent – and, more importantly, never dull. Some of the more popular exercises and training variants are as follows…

Speed sessions

Training at maximum speed is often practised with very short repeats (12.5m, around half a length of a standard pool or a quarter of a length of an Olympic-sized pool) and plenty of rest.   Speed sessions differ from max effort training. Sprinters will often try to swim faster than max speed with the use of long stretch cords pulling them through the water faster then normal. Fins also have a similar effect of generating ‘overspeed’.

Interval sessions

When attempting a session, there are several ways the efforts can be increased to help elevate your heart rate. Four key areas are adjustable to make the session more intense, productive and meaningful…   First, the distance of the repeats you swim. For example, if in week one you attempt 4 x 200m, by week four you should be attempting 4 x 300m. An example of an interval swim would be giving yourself 2mins to swim 100m FC in the first week, before attempting another repeat.

As your fitness improves you’ll get more rest as you swim each 100m faster. After several weeks the ‘interval’ might come down to 1:50mins.   The number of repeats swum may also be increased, adding to the intensity of the session. In the first week you may only make 5 x 100m on your interval before reaching exhaustion. The following week you might aim for 8 x 100m on the same interval.   The aim time is the final variable that can be manipulated. You might decide on 8 x 100m FC with an interval of 2mins but a target of 1:45mins, meaning you get 15secs rest before starting again. After four repeats at this pace the effort might be too much and you slip to 1:50mins. These are the benchmark times and efforts you should bear in mind and record in a training diary.

With a few weeks training hopefully you would improve and can try the 8 x 100m FC with an interval of 2mins and an aim time of 1:45mins. If you make the set, you might increase the number of repeats to 12 or bring the interval down to 1:50mins that’ll encourage you toward a target of 1:40mins.   The aim time is often worked out using your best time and the percentage of effort needed for a particular set. Your coach will ask you to swim at certain percentage efforts for different periods depending on your training cycle, how fit you are and so on.

Heart rate (HR)

Instead of a time-based target, if your coach is familiar with your HR zones they might challenge you to swim to heart rates. Your interval could also be HR-based leading to a set such as 8 x 100m FC with a target of 80% of your max HR and a resting period interval down to 60%.   This means that when you finished your 100m swim, you’d check your HR to ensure it was 80% of your max. You would check it repeatedly until it fell to 60% of your maximum HR.   This style of training is highly individualised and would potentially cause some issues if done in a lane with four swimmers taking different rest periods.

Negative splits

A main set of 400m might be swum in a negative split fashion. To work on ‘back end’ endurance – to help your ability to finish a race strongly – you might race to negative split each 400m.   For this, you could be asked to swim the first 200m at a certain time and then bring the second 200m home 10secs quicker. Alternatively, the effort levels could be targeted so the first 200m of the swim is performed at 60% effort and then the second 200m at 80% effort.

Even split swims

This simply means aiming to offset the fatiguing effect by swimming the second half of a swim at the same pace as the first half.

A 400m swim with a target of 5mins would attempt to be swum in 2 x 2:30min sections.

Mixing strokes

Individual medley training involves swimming all four strokes in the correct sequence as they’re raced in competition. Butterfly starts the sequence, then backstroke, breaststroke and front crawl. The ability to swim all four stokes makes training infinitely more interesting and variable.   It’s worth learning the other strokes for many reasons.

Firstly, for triathletes and recreational swimmers who perform regular FC, it puts a lot of stress through just one range of motion. To mix in some of the other strokes gives the shoulders a new range of motion to help reduce the chance of injury; backstroke is an ideal recovery stroke to unwind too much FC motion.   In addition, overall fitness improves due to the ‘cross training’ effect as you mix muscle groups. The different strokes need effort from different parts of the body. For example, breaststroke being predominantly leg driven and fly a test of your shoulders and core.

Why you should be swimming ‘off strokes’ regularly

Build swims

A build swim would involve a gradual pace and effort increase throughout the duration of the assigned distance. You could either do this time based or with effort levels. For instance, 6 x 300m build FC. The first 100m of the 300m should be at 60%, the second at 70% and the third at 80%.   For a time-based build swim, you could improve by approximately 5secs per 100m for the duration of the 300m. Despite differing effort levels between 100m, the 300m swim is continuous (the rest period will be taken after 300m). If there’s a large wall-mounted clock to the side of your lanes, you might be able to check your split times or hopefully your coach/friend can take them.

Reducing/descending sets

A reducing set would mean that repeat after repeat gets quicker than the previous set. Targets could be assigned as either time based or effort based, depending on yours or your coach’s preference.   For instance, 4 x 200m FC, reduce 1-4 from 60% to max. In this case the first 200m would be swum at 60% effort, the next at 75%, the third might be 85-90% and finally you’d finish the last at max effort.   From a time-based point of view you should aim for specific target times. Now you’d reduce hitting 2:40mins on the first 200m, 2:30mins on the second, 2:20mins on the third and to finish with your best effort. A challenge might even be set that could be to try and break 2:15mins.

Hypoxic training

Breath holding while swim training is used more now to keep the head still during FC swims and improve technique. Unnecessary or excessive head movement during FC will increase resistance and drag, affecting your ability to remain streamlined.   Recent studies have shown that it doesn’t produce the ‘high altitude’ training effects we once thought. Adopting a breathing pattern where you take a breath on alternate sides at challenging intervals (every third, fifth or seventh stroke cycle) will help to keep the head still for longer and instil the sensation of a good, still head position. Turning to breathe

Test set


A necessary part of recording and checking your progress is to test yourself on a regular basis with a benchmark set. Parameters should be kept identical down to the smallest detail.   Perform the test at the same time of day, in the same pool, with a similar warm up before the set. The test sets can take many forms but a common set swum is the 7 x 200m step test.   HR, stroke count and split times should all be checked and noted. Aim to swim the 200m even split. The first 200m is swum at 60bpm below max HR and you descend the set to the last 200m being swum at max HR.   From the results you can record max HR, best time for the 200m, swim velocity (average for 100m in seconds), stroke rate (strokes per minute) and stroke count (strokes per 25m/50m).