The choice between an Olympic distance triathlon or 70.3 is one that many grapple with. Both are a real test of fitness, but which is right for you? They look not dissimilar on paper. But the difference between an Olympic distance triathlon and 70.3 is probably the biggest jump between any of the distances.
The reason is the pacing and nutrition elements. Yes the Olympic distance is challenging, but the 70.3 is on another level. Where most people will finish an Olympic distance in around three hours, you could be out there for seven hours or more during a 70.3
To start, let’s break down the elements of an olympic distance triathlon and a 70.3.
The swim
The swim is a the discipline which changes least between an olympic distance triathlon and a 70.3. The length of an olympic distance swim is 1500M, and makes up a big chunk of the race. Meanwhile, the swim leg of a 70.3 is only 400M longer, at 1900M.
This means that for a strong runner/cyclist, a 70.3 could be much more appealing. Not only is the swim proportionally a lot shorter, they can make up and ground lost in the water a lot easier. In fact, the swim leg of a 70.3 is a prologue as much as anything.
The bike
This is where the difference becomes really profound. The bike leg in an Olympic distance triathlon is 40KM, relative to 90KM for the 70.3. That’s well over double the distance. Not only this, but we will be riding at a lower intensity. We will be spending a LOT more time in the saddle over a 70.3 than during an Olympic distance.
The average bike split for an Olympic distance triathlon is around 1:10-1:20. Over a 70.3 it is over three hours. Someone can complete an Olympic distance triathlon with just about any bike they can get their hands on. For a 70.3 however, we will be in for a long, uncomfortable day on a hybrid or road bike. This immediately creates a pricing barrier.
Very few Olympic distance races have a cutoff, where many 70.3 events will. At an official IRONMAN 70.3 event, you have 5:30 to complete the swim and bike. Allowing roughly an hour for the swim and transition, we have 4:30 or so to complete the bike. While this is a good chunk of time, a flat tyre or mechanical issue we’re unable to fix on our own could spell disaster.
Over the 70.3 distance aerodynamics become more important, and these races can feel a bit like an arms race with top competitors riding bikes that are worth more than some people’s cars.
The Run
When considering the difference between the run at an Olympic distance triathlon and 70.3, we have to consider not only the length of the run, but also how long we’ve been racing for by the time we start the run.
For an Olympic distance triathlon the run is 10KM long, which is still the athletic achievement of a lifetime for many. Meanwhile, we have a 21.1KM run at the 70.3 distance, more than double the distance.
What is far more impactful in my mind is that by the time we start the run during an Olympic distance triathlon we are probably around two hours into our race. Maybe more, maybe less. During a 70.3 however, most athletes will be closer to four hours into the event by the time they start running.
The possibility for mistakes is so much higher when you’re four hours into an event compared to two. I will go into this in a bit more detail later. But do not make the mistake of thinking that because you ran a half marathon once that you will crush the run of a 70.3.
Intensity of an Olympic distance triathlon vs 70.3
While an Olympic distance triathlon is still a test of endurance, for many athletes it is still executed at a high intensity. Many athletes will spend the day at around 90% of their threshold, possibly even higher. From the get go, an athlete will be working fairly hard.
Contrast this to a 70.3 which will take the majority of people closer to six hours. Where an athlete racing an Olympic distance triathlon may start the swim at what they feel is their 1500M pace, a 70.3 athlete racing at their 1900M pace is going to get themselves into a lot of trouble. Instead, I tell those taking a 70.3 on for the first time to think about swimming at their six hour pace.
As the intensity of the race is much lower, the same can be said for the training. Training for an olympic distance triathlon will involve a lot more in the way of hard intervals than 70.3 training, so if this is the kind of training you thrive on then you may want to look at the Olympic distance. Finishing a 70.3 distance gets more clout in some ways, but being able to complete an Olympic distance triathlon in under 2:20 is far more impressive in my book.
Pacing
When I lined up at the start of my first 70.3 I had a half marathon PB of 1:34. I figured that adding on ten minutes for fatigue would get me round in about 1:45 or so.
It took me 2:58 to complete the run of the 70.3.
The issue was a mixture of nutrition (more on that later) and pacing. I knocked out a respectable swim and hopped on my bike. Used to racing the Olympic distance, I pushed on to make up some time. I remember thinking to myself that I hadn’t been passed by any other road bikes, only those on time trial bikes.
Then I started to get passed by road bikes. Soon I stopped passing other athletes altogether, and was undoubtedly going backwards. Looking at my data, I was very much slowing as my heart rate climbed.
Getting off the bike I was looking forward to making up some ground on the run. But I had no legs.
I had not only got the pacing wrong (going off too hard). I had failed to respect the scope of the challenge. Because I could comfortably swim 1900M, ride 90KM and run a half marathon, I felt ready. I was not.
You can get your pacing wrong over an Olympic distance triathlon and still salvage the day by digging deep. But over the 70.3 distance the chances of a massive implosion are much higher.
Nutrition over Olympic distance triathlon vs 70.3
The second major mistake I made was not eating enough on the bike. Over an Olympic distance triathlon you can get round on fumes, or by knocking a gel or two back in the last hour or so. The 70.3 is much less forgiving.
If you are not mindful of your pre race and on course nutrition, you will have a horrible day. In fact, you will probably fail to finish. Your body’s glycogen stores will only last an absolute maximum of three hours. Ever hear marathon runners talk about hitting the wall? This is often simply a lack of nutrition, followed by light headedness and empty legs. There is no pushing through, there is no toughening up, your body is out of fuel.
By the time you get off of the bike during a 70.3, you will be entirely fuelled by what you have consumed during the race. If you haven’t eaten enough, at the right time, or in the right way, your race will grind to a halt with bloating, nausea and other unpleasant gastrointestinal issues. There’s only so fast you can run when trying not to vomit all over your expensive running shoes.
You need to practice your nutrition in training, which adds an extra level of complication, and cost to your preparations.
If you need help with your 70.3 nutrition, check out a free sample of my IRONMAN 70.3 Race Day Nutrition course here.
Conclusion
Which distance you choose to target is completely up to you. If you can’t swim freestyle or run currently, then an Olympic is a much better target. Meanwhile, if you find having a big goal such as a 70.3 more motivating, there is no reason you cannot target it. However, if you are targeting a 70.3, I recommend at least one Olympic race as a warm up.
If it all feels a bit overwhelming and you need some guidance, learn about ways in which I can help you here.
