Monthly Triathlon Training Advice
An Ironman 70.3 is the first step towards the world of long-distance triathlon. With its 1.9km swim, 90km bike and 21.1km run it’s an event that will cause any rational non-triathlete to think you’re slightly crazy. Even the thought of practicing these distances separately in training can seem like a big deal.
For this reason, it’s a race that requires serious thought and preparation. So in this month’s blog I wanted to talk about some of the essential things you’ll need to consider in the lead up to Ironman 70.3 race day.
Let's focus on six things that could either save your race or make you faster.
1. Simple Hydration
Seeing as you’ll be riding your bike for several hours it’s vital that you can take a drink easily. If a bottle is hard to reach, you’re less likely to use it. Fact.
Aside from convenience, it’s also worth considering aerodynamics. Standard bike bottles placed in bottle cages on the frame add to your overall drag. Research by Cervelo has shown that a bottle placed in a cage on your down-tube results in a 4-watt drag penalty. Whereas a bottle mounted between your forearms (on your tri-bars) or behind your seat creates negligible drag.
Another option is to use a re-fillable bottle with a straw, which can be mounted on your frame or between your arms. These are aerofoil shaped to help reduce drag and offer a good combination of practicality and aerodynamics. Examples include the Profile Design Aero HC and the Nathan Sports AP Pro.
2. Swim Volume
When you step up from a Sprint or Olympic distance to an Ironman 70.3, the relative ratios of each discipline change. For example, the bike and run are over double the length of an Olympic distance, while the swim is only 400 metres longer. So an Ironman 70.3 is significantly less swim-dependent than an Olympic or Sprint distance triathlon.
To illustrate this point, the overall winner of Ironman 70.3 UK in 2015 came 95th in the swim phase, over five minutes behind the leaders. And yet he was still able to catch and pass everyone during the bike and run sections. This almost never happens in an Olympic distance race.
In terms of training, this means that some of your run and bike workouts will need to increase in length significantly. Whereas you can continue to swim-train in a similar way as you might for an Olympic distance triathlon.
For more a specific look at swim volumes for an Ironman 70.3 you can preview my training plans from here.
The bike section of an Ironman 70.3 lasts anything between two hours 30 and four hours, most of which you’ll spend perched on the end of your saddle. Not surprisingly, bottom discomfort can be a real issue.
Nagging saddle soreness is a form of fatigue - a pain in the rear end that'll sap your morale and make you want to quit. Thankfully over the last few years saddle designs have evolved to benefit the backsides of long distance triathletes.
Split-saddles such as those by ISM and Cobb are now common at long-distance triathlons. They are designed to spread the load and reduce the pressure on the sensitive areas of your under-carriage. They are often slightly heavier than standard racing-bike saddles but they make up it by allowing you to maintain a comfortable aero-position for longer.
Some bike-fitting studios even let you try various saddles while they measure the pressure-points as you ride, so that you can find the right model for your unique shape. You could Google the term "bike saddle pressure mapping" to see if this is available near you.
4. Pace Judgement
Perhaps the biggest difference between racing an Ironman 70.3 and a shorter triathlon is the importance of pacing on the bike. Get this slightly wrong and your run split will suffer big-time. You could even end up walking the run section due to muscle soreness or cramping.
A power meter can really help you here, because it tells you exactly how hard you’re pedalling versus what you're capable of in training.
Research suggests that the optimal power output for an Ironman 70.3 is 75-85% of your Functional Threshold Power (FTP). Slower athletes should aim for the lower end of this range, while potential race winners might aim for the full 85%. For more information read my blog about Ironman 70.3 pacing.
To make life easy you can estimate your FTP by doing a 20-minute maximal cycle time trial, recording your average power and then multiplying the outcome by 95%. If you don’t have a power meter you should consider investing in a Stages or Garmin Vector S. They aren’t too expensive and you can switch them between your training and race bikes.
5. Race Suit
In a relatively long race such as an Ironman 70.3, your choice of clothing takes on greater significance. After all, anyone can cope with rubbing or discomfort for 90-minutes but having it for five hours requires a different level of suffering.
The first consideration is whether to have separate bike and running gear or just one outfit for the whole thing. If you’re more worried about comfort than time, you should use two outfits. If you're chasing a time-goal you should race in one suit, so you don't lose 10 minutes in transition while you change clothing.
Wind tunnel research has shown that a one piece skin suit with short sleeves can save you 5 watts in an Ironman 70.3 versus a sleeveless suit. And another 5 watts versus a two-piece tri suit.
Whatever you go for, I recommend finding a suit that has thin but dense padding for your bottom and handy pockets for carrying gels. Just make sure you train in it first, so you’re confident that it’s comfy enough. And apply plenty of lube such as Vaseline or BodyGlide to all your moving body parts.
6. Planning For The Worst
If you puncture during an Ironman 70.3 you could end up stranded 20-miles away from the transition area. I know, because I have experienced this! You'll also lose precious time while you attempt to fix it. So it’s well worth planning for the worst case scenario, because it does happen.
Rule one is to use relatively new tyres, as these are always less likely to puncture. Rule two is to use tyres with an optimal blend of puncture protection and low rolling resistance. Check out this website that shows the latest research on rolling resistance and puncture proofing.
Rule three is to use a puncture protection sealant, such as CaffeLatex or Stans NoTubes. These foamy products are designed to fill small punctures as you ride. They don’t work 100% of the time but they’re still better than nothing. They work better if you have tubeless clincher tyres.
Rule four is to carry two CO2 quick-fill canisters and a Presta adaptor for speedy inflations. They will save several minutes versus using a pump and they'll get your tyres nice and hard. Just make sure you practice using them first.
Rule five is to inflate your tyres properly in the first place. Read the guidelines on your tyre walls but normally you should aim for 100-120 PSI. If your tyres are too soft you're more likely to get pinch punctures.
And finally, rule six is to carry a spare inner tube and tyre levers. Or if you use tubular tyres you could carry a spare tyre - or just rely on rules one to five instead.
Fingers crossed it doesn't come to this!
How to use the drafting rules to swim, bike and run several minutes faster...
I'm currently writing a book about Half Ironman triathlon. There's a whole section about different ways to knock several minutes off your race times, without you necessarily needing to train more or be fitter. The book will be launched in March 2018 and this blog is taken from the first draft.
During a triathlon you can gain a significant advantage by riding, swimming and running behind other athletes in a legal and respectful way. It’s known as drafting and it's free speed waiting to be had, so don’t leave it on the table. Here we’ll explain how to get it right.
Research shows that swimming 50 cm behind another athlete reduces your drag coefficient by 21%. Whereas swimming to the side of another athlete can reduce your drag by around 7%. In an Olympic distance or half Ironman triathlon, this could save you up to two minutes.
What’s the best way to do this? In an ideal world you should aim to swim behind someone who’s slightly faster than you. To do this you may have to start off a little nearer the front than you might normally, and then swim hard for the first couple of minutes.
If you’re not comfortable with that idea, you can still benefit by swimming with people who are of similar ability to you. In this situation you might feel like you’re going too slow and you’ll be tempted to overtake. Whereas in actual fact you’ll be swimming at a good pace, it just feels easier because you’re drafting.
A word of caution, don’t follow other swimmers blindly. Make sure the person you’re following is heading in the right direction and not weaving all over the place. Be prepared to find another pair of feet if you need to.
Also, try not to infuriate anyone by touching their toes. Nobody will be cross about you drafting behind them if they hardly know you’re there. It’s up to them to swim behind another athlete if they want to, you just need to worry about your own race. Just try and be respectful.
Most (not all) amateur triathlon events are non-drafting. Meaning you’re not allowed to ride directly behind the rider in front of you. At IRONMAN 70.3 events for instance, the legal drafting distance is currently 12 meters. This is measured from the front of the bike in front, to the front of yours.
Riding at this legal distance reduces your drag coefficient by around 9% compared to riding solo. That can mean a saving of around 25 watts, depending on conditions. Put another way, you’ll pedal approximately 10% less hard for a given speed. There are lots of variables to consider, but the point is that legal drafting can help you knock minutes off your bike splits. Or enable you to conserve more energy for the run (see our guide to half Ironman pacing).
Don’t feel bad about it either. With up to 2000 cyclists all on the same route, there’s literally not enough room on the road for everyone to leave a massive gap. So just make sure you abide by the race rules and if anything leaving a slightly bigger gap than necessary. The pace will ebb and flow, so you’ll need to concentrate on maintaining a legal distance throughout. Just be considerate to other athletes and be prepared to ride on your own or at the front when needed.
There is a small benefit to drafting when running. The faster your run or the greater the headwind you’re running into, the more benefit you’ll experience. At a relatively fast running speed of 11 mph or 17 kph, it has been shown to be two percent easier to run directly behind another runner. This benefit shrinks exponentially, the slower you run. And the benefit grows again, the stronger the headwind you’re running into.
So there is potential to save energy for a given speed, or run faster for a given amount of energy. But not as much as there is for the swim and bike sections. Still, every second counts when you’re chasing a time.
1. Med Sci Sports Exerc. 2003 Jul;35(7):1176-81. Drafting distance in swimming. Chatard JC, Wilson B.
2. Computers & Fluids. 2012 Nov; 71:435‐45. CFD simulations of the aerodynamic drag of two drafting cyclists. Blocken et al.
3. J Appl Physiol Respir Environ Exerc Physiol. 1980 Apr;48(4):702-9. Effects of wind assistance and resistance on the forward motion of a runner. Davies CT.
Swim, bike and run faster with this Ironman 70.3 triathlon pacing guide…
An Ironman 70.3 is the first step towards the world of long-distance triathlon. With its 1.9km swim, 90km bike and 21.1km run it’s an event that can take anything from four hours, right through to eight.
So let’s say for arguments sake it takes you five or six hours. That’s a LONG time to be swimming, cycling and running, and you’ll need a pacing strategy that reflects that. If you treat it like it’s an Olympic distance triathlon you’ll pay a hefty price later in the day.
Thankfully the advice in this feature shows you how to pace yourself properly, so that you feel strong throughout. The secondary benefit of getting your pacing right is that it gives your body a fighting chance to process all the gels, bars and energy drinks that you consume during the event. So not only will this pacing strategy help you to race faster, but it will also keep you more energised along the way. Let's start with the swim...
Swim Pacing Guidelines
This is the only time in the race when you should go above 6 out of 10 intensity - and only at the start. Aim for 8 out of 10 intensity initially and use the first 300 metres of the swim to find your place in the group and hopefully get in the draft-zone of similar-level (or slightly faster) swimmers. After a few minutes you should be able to ease back down to 6 out of 10 intensity and maintain that right through to the end of the swim. If you're a nervous swimmer, start off at 6 out of 10 and stay out of harm's way.
Don't sprint like Usain Bolt and build up lots of lactic acid in your legs. This is a five or six hour race and you should not be out of breath. Jog into transition. You still need to be smart in transition - but save your legs for later.
Bike Pacing Guidelines
Use a power meter as your first guide, with heart rate as a back up. If you don’t have a power meter you can use heart rate and feel. Aim to ride at a consistent power output with the difference between your average power and normalized power being as close to zero as possible. In other words, no spikes in power for hills or sprints. If it’s a hilly route, you might benefit from a compact chainring and a rear cassette with a 30 or 32 tooth chainring. This should give you enough gears to maintain a nice steady power output without spikes, on all but the hilliest routes.
4 to 5 hour Half Ironman Athletes:
5 to 6 hour Half Ironman Athletes:
6 to 8 hour Half Ironman Athletes:
Jog. Be smart, don’t waste time. Save your legs for the run
Run Pacing Guidelines
If you paced the swim and bike sensibly, you’re in with a fighting chance of running to par. Either way, you’ll still be tired by the time you hit T2. After all you’ll have been racing for 3 to 6 hours already. So don’t expect to run fast like it’s an individual half marathon. Realistically you should be aiming for an intensity that’s similar or slower than your full-marathon pace.
4 to 5 hour Half Ironman Athletes:
5 to 6 hour Half Ironman Athletes:
6 to 8 hour Half Ironman Athletes:
My final tip is to make sure you treat your half Ironman with respect. Use accurate and recent data to plan your pacing strategy, rather than guess work. As well as getting your pacing right, you need to think carefully about nutrition. This principles in this Ironman nutrition blog will help you. For more training advice check out our half Ironman schedules here.
By Phil Mosley.
Check out Phil's Half Ironman Training Plans for beginner, intermediate and advanced.
Copyright © 2016 Philip Mosley
The Serious Training Blog
Train Smart. Race Fast.
Phil Mosley is a triathlon coach and writer.