What is a negative split and why is it useful?
Heard the phrase 'negative split' thrown around a lot but unsure what it means? Here's our explanation and a guide to why it's useful
Negative splits have been spoken about for many years in endurance sport.
From racing to training, it’s an approach many athletes try and master and coaches encourage for a strong performance.
Arguably, this tactic or way of racing is much more popular in running than any other sport, especially in the marathon or half-marathon distance, but it can also be applied to triathlon.
Using this style of pacing could see you excel in your performances and we’ll now look at how…
What is a negative split?
A negative split is simply the practice of completing the second half of a race or discipline faster than the first half.
In triathlon, this means pacing yourself so that you have enough energy left to go stronger during the latter stage of the race, whether in the swim, bike, or run.
The term ‘negative’ comes from the idea that your splits in the second half are numerically lower (faster) than those in the first half.
For example, if you’re running a half marathon (21km), a negative split would involve running the first 10km slightly slower than the second 10km.
The same principle can be applied to swimming and cycling, where you would try and save energy early on to push harder and faster toward the end.
What are the benefits of negative splits?
1. Energy conservation
One of the main benefits of delivering a negative split within a race is energy conservation.
By starting at a steadier pace, you avoid burning your matches early and faltering towards the end of the race.
In triathlon there’s a phrase that the athlete who slows down the most essentially wins the race.
This is where a negative split can benefit you. If you still have energy towards the back end of the race and don’t burn out, chances are you will perform much stronger.
2. Better overall performance
Generally, many athletes who perform better in the second part of the race or discipline will finish the race in a faster and stronger manner.
If you start conservatively and allow the body to build into each leg of the race and be fully warmed up this can allow you to push on stronger towards the end.
Compare this to the fly and die approach where you go out hard and deplete your energy levels quite fast!
3. Psychological advantage
Moving past athletes when you’re in the middle of a race can provide you with a psychological boost and help you push on even more.
If you’re making your way through and up the field, chances are you will start to feel stronger and have more energy as you chase people down.
Whereas on the flipside it can be very demoralising to have people continually pass you if your energy is flagging!
Does negative split mean the same for all sports?
While the concept of a negative split is the same across swimming, cycling and running its effectiveness and delivery can be a different and harder to deliver across the disciplines.
Swimming
In swimming, a negative split is less commonly practiced but can still be beneficial, particularly in longer-distance events.
However, the challenge in swimming, particularly open water, is if you start too slow you’ll be caught up with other swimmers, pushed around and may struggle to find a rhythm.
Generally, in swimming it’s good to start fast, settle into a pace and after the turnaround buoy or halfway see if you can increase your speed and push on to the finish.
Cycling
Rather than seeing the cycling leg as half slower, half faster, you can see negative split more in terms of pacing.
Due to the nature of varied courses, hills and wind it can be hard to negative split a bike leg.
What works better is for example pushing the pace on the climbs and the flats, and using the downhills or rolling sections more to recover.
In this way you are still conserving energy for the harder parts of the course leading to better bike splits.
Running
Running is really where it’s easiest and most common to aim for a pure negative split. It’s a tactic used widely in endurance running and also triathlon races.
By starting the run steadier, allowing your legs to get used to the transition, taking on some fuel and hydration you can then prime your body to run even faster.
This will make the difference between blowing up or running a PB!
Triathlon
As triathlon is three disciplines it’s important you look at the pacing of each sport individually, not the race as a whole.
How you pace yourself and race the swim will affect the bike and the bike the run.
You want to be looking at energy conservation so that when you start the run you’re able to push on. If you start the whole race too fast and strong it can be a long day out!
How to successfully do a negative split
Successfully executing a negative split in a triathlon isn’t easy.
It takes practice in training, good physical conditioning and being disciplined in the race. Here are some key tips to help you.
1. Know your pace
A successful negative split can only come from knowing your ability on race day and understanding the pace that you can execute.
This comes from key training sessions at race pace, understanding your numbers or effort and knowing what you can do.
If you just guess or assume you can go faster and haven’t tried this before, it’s not going to end well.
Knowing how much a pace or speed will take out of you is crucial.
2. Start conservatively
This can be hard to do in triathlon, particularly when racing. Most people start fast and hard due to the excitement, adrenalin and chasing other athletes.
You have to be disciplined to know your ability, know what you’re trying to do in the race and remember that you want to have a stronger second half!
As I mentioned above, this isn’t about starting the swim or bike slow, it’s about knowing how to pace yourself, when and always finishing strong.
3. Stay disciplined
It can be hard to pull back on the gas, especially if people are flying past you, but if you trust yourself and what you’re aiming to do, the hope is you’ll pass them later.
Everyone feels good at the start of the race, but it’s those who feel good after half way or still have energy left who’ll cross the finish line first.
4. Monitor your energy
A key element of a negative split is also going to come from your fuelling and hydration during a race.
If you’re not fuelling and replenishing lost carbohydrates, you won’t have the energy to be stronger in the later stages.
It’s important to fuel energy with things like energy gels or energy bars, top up your hydration levels and keep the glass full.
Even if your pace may be starting slower, you still need to be giving your body energy, especially in events that last longer than 90mins.
5. Finish strong
This is the simple part! You really want to push on at the end and empty the tank.
If you’ve paced yourself well, been disciplined and patient, you should have resources left over to really finish fast.
For more running advice take a look at our beginner’s guide to Zone 2 running and our guide to tempo runs.
Andrew Woodroffe
Performance triathlon coach and age-group Ironman triathlete 
