Why sprinting matters – even for endurance swimmers

You don’t often hear “lazy” linked with “Ironman”, but the title words for this story were actually said by a friend of mine and someone I often train with.

This person is a phenomenal athlete and would struggle to meet anyone’s definition of lazy. As well as competing in Ironman triathlon (and often claiming age-group podium spots), they work full-time and have a family.

Why endurance athletes resist sprint training

So the quip was funny but disingenuous. But they contain an interesting insight. Sprint training is hard. It’s especially hard if you’re an endurance athlete and happiest holding a steady pace for hours. It drags you quickly and painfully out of your comfort zone.

It’s not really laziness that discourages long-distance athletes from sprinting; it’s discomfort avoidance. It’s easier to stick with what you’re good at.

Mileage anxiety

As well as triathletes, I also swim with incredible marathon swimmers – people who can swim for hours, often in cold water. They are also reluctant sprinters, but for different reasons. Their mindset is one of continuous swimming. If you truly sprint hard, you need lots of rest to recover. They find it hard to crank up the effort in the same way that sprinters do, and therefore don’t feel as if they need the same rest. But resting isn’t slacking; it’s how you allow your body to prepare itself for the next effort.

Finally, resting lots means fewer lengths swum, but a core metric for distance swimmers and triathletes is their weekly mileage. Sprint sessions reduce their averages. They feel anxious if they don’t log lots of miles.

Why sprinting matters

Still, whatever distance you’re training for, or even if you’re not training for anything and simply enjoying the pleasure of swimming, sprinting is good for you and will help your long distance speed. Here’s why:

Improved anaerobic capacity

Sprinting trains your anaerobic system. If you do long distance races, this could help you tactically – for example, if you want to catch a pack of swimmers for a better draft, overtake another swimmer or make a break at a turn. Even solo swimmers sometimes have to increase speed – for example, to reach a landmark before the tide changes.

Enhanced neuromuscular efficiency

Sprint sets sharpen your stroke mechanics and increase muscle recruitment. This, in turn, should make your regular pace feel easier and more efficient.

Mental toughness & focus

Sprinting demands precision and intensity, which builds mental resilience and sharpens race-day focus.

Boosted VO₂ Max and lactate threshold

High-intensity efforts can elevate your aerobic ceiling, allowing you to sustain faster paces over long distances.

It’s a Renaissance Swimmer trait

In addition to the above, developing your competence in a wide range of swimming domains is a feature of a Renaissance Swimmer. The aim is to become an all-round swimmer, able to sprint over short distances as well as cover long distances.

Still, there are a couple of potential downsides to sprinting.

Increased injury risk

Sprinting stresses muscles and joints more than steady-state swimming. Without proper warm-up or technique, it can lead to strains or injuries. On the other hand, it can also reduce the risk of overuse injuries by delivering training benefits on a lower volume.

Fatigue & recovery demands

High-intensity sets are physically demanding. Overdoing sprints can interfere with your base endurance work or lead to burnout. This doesn’t mean you should never do them, but do them judiciously. Personally, I find the change of pace of a sprint set refreshing.

Technique breakdown under fatigue

Sprinting with poor form, especially when tired, can reinforce bad habits that carry over into longer swims. Take a “technique-first” mindset into sprinting – you should still swim with your best possible technique at speed and when your limbs feel heavy.

A Renaissance approach

Being a Renaissance Swimmer means embracing the full spectrum of swimming. Sprinting practice isn’t just for swimmers who race sprints. It’s for anyone who wants to swim smarter, stronger, and more completely.

How to do a sprint training session

If you’re new to sprinting, introduce it gradually. Add a few high-speed lengths to a regular training session (or, if swimming in open water, a few short sections where you increase speed).

When you feel ready, dedicate an entire training session to sprint work.

Remember, distance covered is not the goal. In a sprint training session, you might only cover 30 to 60% of what you do in the same time in a long-distance session.

Warm up and prep

Start with a good warm-up – 10 to 15 minutes – and include a range of strokes and some technique focus. Then, move on to something where you start testing your speed. We often call this the “prep set”. It might include some half-length sprints, a descending set (e.g. 4 x 50m FC, getting faster with each swim) or a build set (e.g. 4 x 50m, start each 50m slow and finish it fast).

The main event

Once that’s done, you can move on to the main set. Use your imagination here. The aim is to cover short distances (25m or 50m) at maximum effort. If you do this properly, you may find you need to spend 1 to 2 minutes recovering after each short swim. If you really can’t bear to stay still, you could do some gentle backstroke between sprints.

You could also try longer efforts – 100m or even 200m – but these will be sustained fast speed efforts rather than all-out sprints, and will be very draining. Use these sparsely and allow for lots of rest.

Throughout, stay focused on technique and think about streamlining off the walls – this can really help your distance swimming.

Wind it down

Allow 10 minutes or so at the end for a relaxing cool down. Do some easy backstroke or technique-focused drills. This will help you feel fresher and stronger next time you swim.

It’s easier to do your sprint training in a pool where you can precisely track your speed and distance. However, these ideas could be adapted to open water, too.