Pacing in Ironman

Pacing in Ironman

How disappointing it must be to have a great bike section and then suddenly see your race fall to pieces in the run, the marathon! It’s not the first time that we read about this happening to athletes in an Ironman. Some start wondering what could have gone wrong and the first answer is usually that they haven't done enough training on the bike. So they go back home, pile up miles and miles of bike training, only to come back the following year, possibly with a faster bike split, but the same result on the run.

At this stage these athletes might feel frustrated and start hating the race. But the reasons for such a problem could be simpler than they imagine. Improper nutrition could be one such reason. For example, not taking enough fluid and carbs on the bike can lead to a drop in performance or even a complete halt.

Pacing could be another possible issue, and I would like to expand on this subject, as it is crucial for long distance racing. Ironman is a long race, the best take 8 - 9hrs and the rest of us can take anywhere up to17hrs. To keep a good pace going in relation to your ability, you need to pace yourself well during the whole race. Everyone needs to understand that a conservative bike split can give you a strong run. A lot of athletes get this wrong and you see a lot of people walking – especially in the second half of the marathon – after blasting it on the bike.

I remember last year during my first Ironman in Switzerland. I went with the target of running the whole marathon, and didn’t want to walk one meter of it. On the bike I persuaded myself that I had to keep it cool and start at a very conservative pace. Of course loads of people flew past me, and it was tempting to go with them. There was a guy on the first of three laps on the bike who went up the hill like mad. He was hammering on the paddles and twisting his body from side to side. Of course he flew past me, but on the last lap I overtook him on the same hill. He didn’t look amused anymore but he looked exhausted. I met the same person on the run and I lapped him twice. I leave it up to you to decide what went wrong with his race plan.

So what do you have to do to avoid such a result?

The first thing you have to do is work on your pacing on your long bikes on a Sunday. Start easy to steady and work up to a pace that you can sustain for 6hrs. Remember that after the 6hrs ride you have to run as well. Using a heart rate monitor will help you pace yourself better. You need to keep it at Zone 2, which is your aerobic zone. (70 – 75% of your max heart rate) Start the first 2hrs at just below that zone, then work up to Zone 2. Always hold back in the first two hours of your bike ride. In an Ironman if you blow up early you can never recover your race and it will be a painful experience. You might experience an increase in your heart rate after 3-4hrs due to fatigue. At this stage you need to gauge your effort according to how you feel.

Another option is to use a Power meter on the bike to help you pace yourself better. There are various Wattage meters on the market such as SRM and Ergomo. (www.ergomo.net) Wattage meters are still a bit expensive but they can be a great aid to pace yourself well, together with your heart rate. Wattage is a far more accurate way to gauge effort. Power is more realistic than heart rate as the latter takes a while to get into zone. Let me give you an example:

In my case, during an Ironman I should keep roughly 240W which gives me a time of 5hrs 15mins, this at an average heart rate of 155! So after the swim usually my heart rate is a bit high since you are trying to get through transition as fast as possible. (I know this is an Ironman but why waste minutes in a transition area if you can avoid it?) Once on the bike I start at a very comfortable pace to get my heart rate into zone, and work around the 240W mark. This way I know that my legs are not doing too much work too early and I can get my breath back. Once I go past the first 40km I am on target pace both with my watts and heart rate.

This is a bit different during training. When you start your long bike early morning you can notice that if you want to keep your effort at your Ironman Bike ride pace, your heart rate is lower for the first 2hrs or so of the ride. This does not mean that you are not doing the work, but it means that with the help of a power meter you are keeping the effort at your actual Ironman potential pace without blasting the first two hours of the ride to get your heart rate up and then just hanging on for the rest of the ride!

Using a Power meter to pace your bike ride in an Ironman can bring you a strong bike split and most importantly a fast run split.