Tame your first Ironman: Pt 2

Part two of our taming Ironman tips, covering nutrition, bike fit and pacing




An Ironman is almost certainly the longest and slowest race you’ll ever do, so it’s very important to be comfortable while racing. Compared to a sprint- or standard-distance triathlon, your bike position will need to be higher at the front. Most people don’t raise their bars enough for iron-distance racing and, as a result, spend the second half of the ride stretching their backs out and going slower. Bringing your seat back a little will also help.

The bottom line is that you need to have your bike set up by someone who understands long-distance triathlon and the importance of comfort as well as bike fitting. In an Ironman, low is slow and comfort rules.


Think of the bike as a mobile kitchen. The frequency of eating and drinking is one of the keys on race day and the easier it is, the more likely you are to do it. As you become mentally tired, you can reach the point where your body won’t make any extra effort, so easy access to your food is vital, whether it’s a bottle between your aerobars or a bento box on your top tube.

You eat on the bike to make sure you’re ready for the marathon. Try consuming about a gramme of carbohydrate per kilogramme of your body weight per hour. Also, look at last year’s results from the race you’ve entered to gauge how long the ride will take. Then you can start to calculate how much food you’ll need.

When it comes to food, carb-based ‘food drinks’ are becoming more popular and tend to work better for athletes working at higher effort – while solid foods tend to work better for slower athletes who are competing for longer and working at lower intensity. Gels suit some people but can also upset stomachs more than other foods. If I were coaching 10 people for the same Ironman, I would have 10 different nutrition plans. The key is to experiment and create your own nutrition plan that’s specific to your needs.


Pacing is the single most important thing to get right on the day. If there’s an Ironman mantra to remember, then it’s this: start with the same effort at which you’ll be able to finish. This is most important at two critical times during an Ironman – the first half of the bike and the first half of the run, in that order of priority. Heart rate and power are both great measures to use for pacing.

Here’s an example of a pacing strategy using heart rate. Let’s say you have an anaerobic threshold heart rate of 175bpm – the maximum heart rate you can sustain for one hour on the bike. In the first half of the bike in your first Ironman, you’ll aim to hold about 20 beats below threshold, ideally between 150-155bpm. In the second half of the bike, you’ll be in a rhythm and it’ll be easier to pace yourself. If your heart rate drifts up to about 155bpm, that’s okay – but it shouldn’t go any higher. On the run, you should aim to do the same, heading out at a heart rate no higher than 150bpm.

Remember, you can’t have a great day based on the first half of an Ironman, but you can certainly mess it up. Stay in control.


Read tame your first Ironman: Pt 3 (tips 8-10 3/3)