Deciding how to pace the 70.3 bike is difficult. Pacing sprint and Olympic distance triathlons as a competitive athlete is fairly easy, you just go about as hard as you can. As an Ironman athlete, you will be somewhere in zone 2, but the 70.3 distance? This is where things get interesting.
We can’t afford to just go hard and hang on (I’ve tired it, it doesn’t work), but neither can we afford to sit there in a comfortable zone 2 and watch people flying past, so how hard can we go?
Well, it’s going to depend on our fitness levels, the elevation of the course, our age and various other factors. Let’s take a look.
Basics
TrainingPeaks recommend an athlete pace the 70.3 bike at an intensity factor (IF) of between 0.72-0.85. IF is a representation of how close you are to your threshold, and is equivalent to a percentage of FTP, so we’d looking at somewhere between 72-85% of FTP.
72% is an all day pace for many people, and will feel far too easy for race day, where 85% is definitely uncomfortable to sit at for prolonged periods, so how do we decide where we sit?
On a basic level, the shorter an effort, the longer you can sit at that intensity for. Someone can ride much faster over five minutes than an hour. The same is true over a 90KM bike leg.
A professional athlete who is completing the bike leg in around two hours will be able to ride at a much higher intensity than an age group athlete who is going to take over four hours. It’s just how the human body works.
The principal take home point here is that the longer you are out there for, the easier you effort needs to be to ensure that you can sustain that effort.
Age
An athlete’s age will have an impact on the intensity they choose to ride at.
This isn’t to say that someone who is in their 60s but very fit would have to target a lower intensity than someone who is in their 20s and very out of shape though, but someone who has maintained a similar level of training over the last 20 years probably won’t be able to ride quite as hard as they could ten years ago.
Course elevation
The elevation of a course will have a very real impact on the ability of an athlete to hold a target intensity, as it will increase the amount of time an athlete spends on the course. A very hilly course could add on as much as an extra hour to some people’s bike splits.
This is where we have to remind ourselves that duration is more important than distance. Rather than being focused on arbitrary targets such as going sub 3 because that’s what their mate did, instead understanding that the profile of your course could be very different, and understanding that you could ruin the rest of your race by trying to average 30KPH over a hilly bike course, where your friend cruised that on a flat course.
Fitness Level
As mentioned earlier, the fitter someone is, the harder they will be able to ride, but I do need to break down the different components of fitness.
The primary influencer of performance over a 70.3 distance race is aerobic fitness. You may be able to ride 40KM in an hour, but that doesn’t mean you will be able to ride 90KM in 2:20 and have a great run. In the same way that I could run a 5K in under 18 minutes ahead of my first IRONMAN, but still took over five hours to complete the marathon.
Riding a fast 90KM requires a LOT of aerobic fitness, and also a very good dose of muscular endurance on top. You can work out what you need to focus on in your training with how you feel towards the end of a long ride. If your legs are on fire, you probably need to do more muscular endurance training, while if you’re just fading as your heart rate soars, then the odds are a greater volume of low intensity training is what you need.
Race Simulation
I like all athletes ahead of a 70.3 to do a race simulation. This has a different role for first time athletes and those looking to improve their time.
For the first time athlete, it’s a big wake up call on how difficult the distance really is. Starting with a 1900M swim, we then do a 90KM bike at race pace, and run 5KM at race pace. We then do an extended cool down as 5KM easy to wind down. This will be around five hours for most first timers, and tends to provide a very sobering experience for those who have mainly been training the disciplines in isolation thus far. While I don’t do it to knock athletes down, it is important they understand just how tough the run can be, and how they need to pace the swim and run carefully.
For the experienced athlete it’s a very different matter. This is a chance for us to find out if our race power target is achievable. We may have it in out head that 270W will be our race power, but if we do a 1900M open water swim first, hold that power for 90KM and then try to run at half marathon pace, our legs might have something else to say about this.
I would much rather someone discovers their target is a bit ambitious in training than on race day. It’s always worth being slightly conservative with your bike target in my eyes, as most of the time people have a poor run it’s less to do with their run fitness, and more to do with them bing overly ambitious on the bike.
What shouldn’t influence bike pacing
Many athletes know they are poor runners so try to make up time on the bike to extend their advantage, or they are much better on the run than others, so throttle back on the bike to make sure they can unleash their run.
This creates one of two problems. A strong cyclist may push hard to go 2:45 on the bike where they would have ridden 2:50 if they had paced it sensibly. However, if they had ridden the 90KM in 2:50 then they could have completed the run in 2:00, where by pushing really hard to cross the line of the bike in 2:45, they are now on track to run a 2:20 half marathon after being forced to a walk due to fatigue in the legs from trying to extend their advantage on the bike.
Alternatively, you could have a strong runner who decides to soft pedal the bike and dismounts in 3:15 where they could have crossed the line in 3:00 if they had pushed a bit harder. When they start the run they are already way back, but they overtake dozens of people, and that feels good right? Well, it feels good, but the race they should be part of is 15 minutes up the road. Steaming past slower athletes can be good for the ego, but it will hurt your overall result. For a strong runner, finishing a half in 1:30 rather than 1:40 because they took it easy on the bike may massage the ego as they see themselves in the top 5% of run splits, but if they didn’t even crack the top 50% overall, then they need to re-think their approach if they ever want to be on the podium.
Focus on efficiency rather than power
Look, we all love riding to a power target. Knowing that last year we raced at 230W but we can now hold 250W is great news, it really is. But what’s more important than power output is efficiency.
If you could ride 3:00 at 240W or 250W, which would you choose? 240W will leave you with much better run legs than 250. But how can we go faster for less effort.
On the one hand we have aerodynamics. By getting a tri bike, aero helmet, deep section wheels and aero optimised kit we can massively improve our efficiency out on the road. However, this can be expensive. You can get started with a pair of clip on aero bars, but it is an arms race to get as aero as possible.
The next thing we can do is be intelligent with our application of power. Focusing on maintaining momentum we gather on downhills and avoiding power spikes will go a long way to giving us better run legs.
“Give me some numbers!”
It’s incredibly difficult for me to advise on targets without knowing anything about you. This piece has been very broad and general, because there is a huge difference between individuals, however I can help give you some specific targets.
More than that, after deciding on a target, I can provide you with a race plan that interest with your head unit, providing you real time wattage targets to ride to. If you don’t have a power meter, I can provide you with speed targets.
I achieve this using Best Bike Split. Work with me for only an hour and I can email you a race plan that syncs to your computer on race day. Book your race planning session here.
Conclusion
Remember that you are a triathlete, not someone who is looking to lay down the fastest bike split possible or a runner who uses the swim and bike to get to the start of your discipline, you need to reframe yourself in your mind as a triathlete looking to ensure you have the fastest overall split, rather than set the world alight in a single discipline.
If you’re in doubt however, it’s better to back off and go a little easier, to ensure you still have a good run.
