Triathlon average run speed is usually gauged by level of fitness, ability, and run distance.
For instance, what is average to a pro triathlete will be far different from what is considered average for an age-group athlete.
Many newly-minted triathletes have a serious misconception about how to compute what their triathlon average run speed should be.
In many cases the perception is that if you take off a little bit of time from your normal 10k, half-marathon, or marathon times you will be pretty close to figuring out what your triathlon average run speed will be.
EVERY TRIATHLON RUN DISTANCE IS UNIQUE
If you have run several 10k races and are about to enter an Olympic Distance Triathlon for the first time you will most likely be able to figure out your average run speed a bit more easily as the distance is relatively short.
At least it’s short compared to the 21k distance of a half ironman or 42k full ironman marathon distance.
So for instance if your 10k run time is normally around 50 minutes, you might not be far off if you add about 20% to that time and plan your triathlon average run speed around that figure.
Adding 20% would increase your projected run time for the 10k distance in an Olympic Distance Triathlon to around 60 minutes and you would plan your average run time around that total.
In other words, you are assuming that the energy lost in the swim and bike portions of the race would slow down your normal 10k run time by about ten minutes.
If you were to use that same formula for a full distance Ironman Triathlon that requires you to run 26.2 miles you will most likely be in for a shock.
Say you have run several marathons around the four hour mark and add 20% worth of time to that. That’s 48 minutes for a total of 4:48 marathon split in the Ironman.
This is where figuring out your triathlon average run speed gets tricky.
THE IRONMAN TRIATHLON DEATH MARCH
In most cases it would be very difficult for the novice Ironman triathlete to be able to run anywhere close to their average marathon time when it comes to the Ironman Marathon.
Even if they added on 20% more time it would most likely be asking a lot. The projected run time usually ends up being an hour or more longer than expected half a day earlier when the gun sounded in the morning to begin the race.
History shows that very few novice triathletes will be able to run the Ironman marathon from start to finish without a fair bit of walking involved.
The reason for this is that the swim and bike portions of the Ironman are usually mismanaged and by the time the running shoes are put on there’s simply no gas left in the tank.
When that happens the marathon becomes a death march.
A NEGATIVE-SPLIT STRATEGY IS THE KEY
If you try and run an average pace and it’s too fast than ultimately you will hit the wall and run out of gas.
It really doesn’t matter if it’s a marathon race or a marathon within an Ironman. The effect is the same.
A better alternative to trying to figure out an average run pace is to adopt a negative split strategy(there is a link below about this). As a matter of fact a negative split is a great strategy for the swim, bike, and run of an Ironman and not just the run.
Here’s an example….
Say you’re a really great marathoner and have run marathons in around 3:15.
You’ve decided that you will try for a marathon time of 4:00 in the Ironman.
You’ve also decided you are going to run an average pace through-out. For you to run an average pace to achieve a four hour Ironman Triathlon average run speed means that you would be running at a pace of 5:42 per kilometer.
Unless you are very experienced and know what to expect once you get off the bike after the 180k bike ride of an Ironman I would suggest you forget about the average speed concept and use a negative split approach.
Basically a negative split means running the second half faster than the first half of your marathon.
It would make more sense to go out at a pace slower than what you think your average time would be and see how you feel as the run progresses.
So instead of a 5:42 per kilometer pace for a 4:00 expected marathon, run about a 6:25 which is about the average pace for a 4:30 marathon.
Either one of two things are going to happen.
You are going to feel great at about half-way and are going to pick up speed and run a negative-split for your marathon….
Or most likely you are going to feel like death running a 6:25 pace and will wonder what ever possessed you to think you could run even faster.
So in other words, if you feel like crap by reducing your expectations, just how much worse it could have been.
PROS VS. AGE-GROUP TRIATHLETES
The top pros can run an Ironman marathon at a time not too far removed from their average time for a standard marathon.
If a pro runs 2:48 for the Ironman marathon he is mostly likely within ten minutes of his best marathon time when it’s not preceded by a 3.8k swim and 180k bike.
There are several reasons for this.
Pros spend a lot more time training and their endurance is simply better than the average age-group triathlete.
Years of experience in triathlon has also taught them to endure pain and to run through it when most age-group athletes simply stop when it hurts too much.
They also have a better understanding of hydration and nutrition and that’s crucial.
A major reason why many age-group athletes have problems sustaining any sort of a run pace is because they have not fueled themselves properly during the bike and simply run out of gas.
Compound that with swimming and biking way too fast and it’s no wonder they hit the wall early on in the run and any sort of planned Triathlon average run speed goes out the window.