When someone crosses the finish line of their First IRONMAN event they will no doubt ask themselves, “how on earth can you run a fast IRONMAN marathon?”.
For many, their first IRONMAN will result in a lot of walking, nutritional difficulties and disappointment. Someone may be able to run a sub 4 road marathon, but running 26.2 miles at the end of a marathon is a completely different ballgame.
What makes an IRONMAN marathon so difficult?
This is in itself pretty obvious, but let’s delve a little deeper.
Firstly we have the fact we’ve just swam 3.8KM and cycled 180KM, so we’re tired. But where does that fatigue come from, and how does that represent itself?
On the one hand we have the muscular fatigue from the bike. Your muscles are going to be tired coming off of the bike. When you start running this muscular fatigue is going to be very obvious, no matter how fit you are.
Secondly, we have the general fatigue we have accumulated aerobically. From riding up hills and just pushing pedal round for 180KM without stopping, we are going to have a lot of general tiredness that isn’t just located in our legs.
Finally we have the nutritional issues that we are probably suffering with by the end of the bike. It could be we have missed a feed and are feeling a bit wobbly. We may be more dehydrated than we realise. Our stomach is gurgling away as it gets backed up with gels. The chances of us having zero nutrition issues at the start of the marathon is slim. Especially if you are new to the sport.
The big misconception about a fast IRONMAN marathon
If someone has a disappointing marathon the initial reaction is almost universal. They need to improve their running.
There is a lot we can do to improve our running through training. We can include more run volume, more intensity, improve our biomechanics, include strength training, develop our leg spring stiffness, there is a massive amount of tried and tested techniques to run faster.
Now this isn’t a bad idea at all. However, for IRONMAN athletes we need to zoom out a bit.
The biggest reason for a disappointing IRONMAN marathon is getting the bike wrong.
Where IRONMAN athletes go wrong
When we run shorter triathlons, the run is the epilogue. Over a sprint, it may be the last 20-30 minute push to the finish line. I definitely viewed the race this way when I started out. Even over the Olympic distance you probably have less than a third of the race to go once you reach T2. By the time you start the run, you can almost taste the non-alcoholic beer.
During an IRONMAN, the swim makes up a much smaller proportion of your race. As such, the bike and run really are the meat and potatoes of the event. As a result, rather than the run taking up around 25-30% of your day, it can take up closer to 35-40%. We can’t simply expect to be able to go hard on the swim and bike, then hold on for dear life at the end of the run.
Nobody cares what your FTP is when you’re walking the IRONMAN marathon
This is a harsh truth many IRONMAN athletes just aren’t ready to hear. Cycling is where many athletes focus their attention. Incremental gains to their FTP, ceramic bearings, bikes worth more than most some people’s car, helmets which cost more than some people’s bikes. No stone is left unturned in their pursuit of speed on the bike. They spend years working towards a sub 6 bike split, and will chew your ear off about rolling resistance given half a chance.
Buy for them, the IRONMAN marathon… just kind of happens. They will run a good portion of it, but walk big chunks. They’ll spend more time telling you about their bike split than their finish time.
If we want to run a fast IRONMAN marathon, we need to stop focusing so much on the bike. We need to slow down on the bike, maybe losing 5-10 minutes, to allow us to run much faster. If someone told you ahead of the race that you could give up 5 minutes on the bike in exchange for running 30 minutes faster, would you take that offer? Most would without hesitation. So why do so many people insist on squeezing every last drop out of the bike and suffering through the marathon?
Setting yourself up for a fast IRONMAN marathon
There are two big components to a fast IRONMAN marathon.
The first is slowing down on the bike, which we’ve touched on above already. We need to see the race as a whole as ourselves as triathletes, rather than cyclists who participate in triathlon.
The second thing we need is bike fitness in spades. It’s no good telling the broom wagon that you’re just saving your legs for the run as you are bundled into the back of the van with your bike. We need to be able to confidently complete the bike course and feel reasonable getting off the bike.
You are never going to feel strong coming off the bike, that just isn’t going to happen. You have just ridden 180KM after all. But what I don’t want is for the athletes I coach to lie down in T2 questioning how on earth they are going to start the run.
Practical examples
There are a lot of concepts flying around here, so let’s look at some examples of different athletes, and how we expect them to do on race day. For the purposes of this example, we are assuming they are all reasonable swimmers who can complete 3.8KM of swimming without exhaustion.
Athlete 1
This athlete is an experienced road runner, but new to cycling. They have run a number of sub 4 marathons in the past, and would like to do the same at IRONMAN.
This athlete has a strong run, so probably doesn’t need as many interval sessions on the run. They need to keep the long runs in their programme, but will probably only do a hard run evert 2-3 weeks. The focus needs to be on bike fitness. If they fail to do so they may not even make it to the start of the run, or be completely exhausted before they start the marathon, resulting in a run around the six hour mark, which they will find embarrassing.
Athlete 2
This athlete is all in on the bike. They spend half their life in the saddle, and are obsessive over their power numbers. They want to create the perfect bike plan for race day, and finish within the top 10% of their age group on the bike.
If placing well on the bike is all that matters to this athlete then that is fair enough, but why not race long distance time trials instead? It’s an awful lot cheaper, and they won’t have to find time for swimming or running. Their run is likely to be a bit of a disaster. They’ll talk about how they really need to sort their run out, but without doing the thing that would help them the most, slowing down on the bike.
Athlete 3
This athlete is new to both running and cycling, and will be fighting for survival in both disciplines.
For this athlete the focus NEEDS to be on the bike. Once they are off the bike they have one hand on the medal. As the average walking speed is 5KPH, and the marathon is 42.2KM, that means that they can walk the vast majority of the marathon and still get a medal. While they cannot neglect run training, they still need that time on feet, they need to be realistic about what’s possible and ensure that first and foremost they get off the bike within the time limit.
Athlete 4
This athlete is an all rounder. They’re not especially fast in any discipline, but they keep turning up and slowly improving.
As long as they are consistent with their training and pacing on race day, this athlete will be the fastest of all four. They will be obliterated by athlete 2 on the bike, but will pass them on the run like they’re standing still. They will be lapped by athlete 1 when run training, but be an entire lap ahead of them by the time athlete 1 starts the marathon.
I hope you have seen yourself in one of the above athletes, and it has given you some insight into how to get the balance right.
What sessions will help someone run a fast IRONMAN marathon?
If we assume you have great bike fitness and have accepted you need to slow down on the bike, what training sessions will help you boost your speed on the marathon?
The key to IRONMAN in aerobic fitness, so lots of easy runs and long runs at an easy pace are key. Don’t go too long though, runs much over 2.5 hours will take far too long to recover from to make them worthwhile. Focus on the total weekly hours, rather than the length of your longest run.
We also need to include some intensity as well, which should take the form of hill reps, VO2 intervals, lactate work and a sprinkling of tempo/threshold sessions.
Alongside our run sessions, we also need strength sessions to keep us injury free, improve our form and add explosiveness to our running. Lateral lunges, box jumps, lunges and deadlifts should all be a part of training for anyone serious about their run performance. Check out my Introduction to Strength Training for Triathlon programme if you are confused, intimidated or overwhelmed by strength work.
The nutrition piece
I haven’t touched on nutrition much so far, because it’s an absolutely enormous subject. However, as noted at the star of this piece, poor nutrition will mean a poor marathon.
We NEED to get our nutrition right on the bike. While we can never be 100% sure it will stay down, we need to do everything in our power to train our body to handle a high amount of carbohydrate, and find a plan that works for us.
This means finding which food works for us, getting our sodium intake right, understanding how the swim will leave our stomach feeling, and mixing things up to find what works for us.
I am not going to offer and insights at this point as the subject is too vast, but check out my IRONMAN Race Day Nutrition Guide to help fuel yourself for success and reduce the risks of GI distress.
Conclusion
As I’m sure you have noticed, there is no simple answer to running a fast IRONMAN marathon, as there are so many factors, however here are the main takeaways:
- Run fitness is important, but bike fitness is just as important
- Slow down slightly on the bike to run faster, and get a better finish time
- Hit the gym to run faster and reduce injuries
- Focus on getting your nutrition right, as all your training will be for nothing otherwise
Of course, the nailed on fastest way to run a fast IRONMAN marathon is to work with a coach. Check out my bespoke coaching options here.
