When it comes to race time, most runners aim to set a new personal record (PR). While PRs aren’t easy, there are ways to make them more attainable.
Enter negative splits.
If you are shooting for a particular time in a race, it’s important to have a pacing strategy. You need to figure out your goal time for the race and then determine the pace per mile.
In a perfect world, you would run the race with even splits. That means that each mile is exactly the same speed as the next. For our 1:45 half example, that would mean that you run each mile at an 8-minute pace.
However, a lot of coaches and runners will tell you the best way to run a race is to run negative splits.
In this article, we will discuss:
- What are negative splits?
- What’s the difference between negative splits and positive splits
- The pros and cons of negative splits
- Training to run a negative split
- How to run a negative split in your next race
Ready to get that new PR?
Let’s dive in!
What are negative splits?
Negative splits are when you run the second half of a race faster than the first half. So, if you were to run a 5k and you ran the first 1.55 miles in 12 minutes and the second 1.55 miles in 11 minutes, you ran a negative split.
There are two main ways to run negative splits:
- The first is to run the first half of the race easier and then pick up the pace for the second half of the race. This is typically easier for a beginner or if you are not sure how to pace.
- The second is to run even splits for the race and then pick up the pace for the last mile. You may hear this referred to as a “kick”.
For the negative split method to work, you need to have a good idea of what pace you can maintain for the race.
Coach Jay Johnson, who has been training athletes for over almost 30 years, prizes the potential of negative splits:
“Try to run the last 10-15% of the race faster after having run even splits up to that point,” he says.
“For example, in a 10k race, you could run the first 5 miles at an even pace, then speed up for the next mile and then put in a kick for the last 0.2 miles of the race. That would be a great execution of a negative split race plan – running the majority of the race at an even pace, then having two pace changes in the latter stages of the race.”
You can watch American distance runner and Olympic medalist, Galen Rupp, use this method to run an American Record for an indoor 5k.
The pros of running negative splits
There are definitely pros to running negative splits in races.
Running a negative split forces you to start the race at a manageable pace.
This is key. If you blast off the line at a fast pace, it is very likely you will slow down over the course of the race.
In planning to run a negative split, you have to start at a pace you know is manageable for you so that you can speed up as the race progresses.
Starting the race at an easier pace and picking up speed as you run makes it much less likely that your pace will slow at some point in the race because you started too fast.
Another pro about running negative splits is that you will pass people late in the race.
Catching runners in the second half of a race will boost your confidence and give you a goal to focus on.
Most runners follow a similar pattern to our story at the beginning of this article. Start off the race fast, slow as the race progresses, and hold on for dear life the last few minutes or miles.
The problem with this method is that it often leads to you blowing up at some point. As your pace slows, other runners begin catching you.
It can be debilitating mentally to keep having runners pass you as you are struggling late in a race.
Of course, with running your only competition is you – however, passing people in a race can boost your confidence and mood. This can make your pace feel easier and keep you pushing through the finish line.
The cons of running negative splits
There are two main cons to running a negative split.
The first is that it can be difficult to run a negative split, especially for longer races.
To run negative splits, you need to have a good idea of what pace you are capable of running for the race distance. This is something newer runners can struggle with until they dial in workouts and paces.
Longer races mean more time on your feet. This means you have to keep track of fuelling and hydration. Miss a gel, water, or Gatorade in a marathon and you will have a difficult time keeping the pace up later in the race.
Weather can also change during the run. If the temperature heats up, it can be difficult to maintain or increase your pace.
Other factors such as wind and course elevation can make running a negative split difficult or impossible.
The second con to running a negative split is that it requires you to go out conservatively. This means you might not finish the race as fast as you possibly could.
For instance, if you want to run a 20 minute 5k, you need to run a 6:27 pace for 3.1 miles.
You run conservatively for their first mile and run a 6:30 split.
For the second mile, you increase the pace slightly and run 6:25.
For the last mile, you run 6:20 and hold that pace for the final 1.1 miles.
You would finish the race around 19:50.
But what if you ran 6:20 for the first mile and were able to hold that pace the entire run? Doing so would have gotten you a time closer to 19:30.
Running conservatively at the beginning of the race helps ensure you don’t slow down later, but it also means you could potentially be running a slower time than you are capable of running.
Training to run a negative split
There are plenty of ways to train for negative splits. These can be incorporated in intervals, tempos, or even on easy/moderate days.
Let’s use the example above of a 20 minute 5k. You are going to run 3×1 mile for their interval workout.
There are 2 different ways they could do this workout to train to run negative splits.
You could run the first two miles at an even pace and then run the last mile faster.
Mile 1: 6:27
Mile 2: 6:27
Mile 3: 6:20
You could also do the workout, increasing the pace of each rep.
Mile 1: 6:27
Mile 2: 6:23
Mile 3: 6:18
Like intervals, there are two ways to train for negative splits while doing a tempo workout.
One is to increase the pace on the second half of the tempo. I like doing an out-and-back run where I pick up the pace on the way back.
For a 4 mile tempo, you can go out for 2 miles and then turn around and run back to your starting point. If you run the first 2 miles in 14 minutes, then you would try to run the second half in 13:59 or faster.
You could do something similar on a loop course.
The other option would be a cut-down or progression workout.
For a 4-mile tempo, you would attempt to increase the pace for each mile.
Mile 1: 7:10
Mile 2: 7:00
Mile 3: 6:50
Mile 4: 6:40
#3: Easy/moderate runs
You can even train for negative splits on easy/moderate runs. If I’m feeling good on an easy day, I’ll increase the pace on my last mile or two.
The key here is to not overdo it, especially on easy runs. Easy runs are meant for recovery, so that is priority number 1.
If you are running a 9-minute pace on a recovery run, you could increase your pace to 8:30-8:45 for the last mile or two.
This will not be enough to prevent recovery and will get your body in the habit of increasing the pace at the end of your runs.
How to run negative splits for a new pR in your next race
Here are some tips for running a negative split at your next race:
- Check the course and the elevation. If the course gains a lot of elevation in the second half of the race, then it is going to be very difficult to run a negative split.
- Check the weather. Heat, cold, or wind could make it difficult or impossible to run a negative split.
- Know what pace you can run before the race. Again, this is easier for shorter races because it’s easier to determine paces from workouts.
- Incorporate negative split training into your runs before the race.
- Decide when you will increase the pace during the race.
If you have taken care of the things above, then you should have a good chance to run negative splits for a new PR.
When the race starts, make sure you run your pace and don’t get caught up in the crowd.
Settle into the pace you’ve been training at and stay relaxed.
Decide when you are going to increase the pace and do so knowing you are able to hold it the rest of the race.
You’ll spend the rest of the race catching and passing the other runners who went out too hard at the start.
With a little luck, you’ll cross the line with a new PR.
Do you think negative splits are the best way to run a PR? What tips would you add for running a negative split? Feel free to get in touch by email or in the comments section below!
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2 thoughts on “How To Run Negative Splits For A New PR”
Hi Thomas, Well I finished my first ever marathon yesterday at age 55. I started this journey with the goal of breaking 5 hrs. and started 16 weeks ago following your training plans and guidance. All of the information you shared in your Master Class was helpful. Through injuries (shin splints and my back seizing up in the final week of the Taper), I managed to hit the start line and kept thinking of your one of your main strategies of not going out too fast and keeping a constant pace. Here is a question: When the Long Runs each week specify to go Easy and your advice is that they should be 30-90 seconds slower than the race pace, how do you know then what “Easy” should be. I was able to run the longest run (21 miles) at a 11:26 pace and then thought I could run a “race pace” at 10:15 -10:30. Long story short… I started off and did exactly what you said NOT to do – go out too fast… I got to mile 15 and it all started to go downhill. I went from running an average of 10:15 to a 2nd half of 12:40. I just don’t know was “Easy” means on the long runs… With it being my first marathon now I know what to expect and should have gone out slower (10:45 or above)… Advice?
Good to hear from you and great work on the marathon!
My general advice for knowing how ‘easy’ a long run should be – if it feels like you’re exerting yourself, slow down! In other words, sit at a comfortable 2-3 out of 10 for RPE (my guide to RPE may be of interest to you). .
Hope that’s of some help!