As I mentioned in my post-Kona analysis, I had a suspicion that because I was in good top-end shape from peaking for 70.3 Worlds, my endurance would come quick. I wasn’t 100% sure though, so I basically spent the 5 weeks after Kona testing this hypothesis. There are three crucial areas that you can improve endurance in when preparing for an Ironman:
- A long run.
- A long ride.
- A long day.
My goal for the five weeks leading into Arizona was to do my best to improve in all three areas. For the long run, I started off with a steady state run of 30km and slowly increased this run to 40km over the course of four weeks. I don’t think biking is nearly as taxing on the body as running, so I immediately forced myself to do a 5 hour ride, and then did two more of these over the next four weeks. I also built up my interval workouts to a point where my final workout took 3 hours. With regards to a long day, I think it is safest to piggy back this day onto your long ride. So, on the long ride / long day, I would do a 1 hour swim in the morning of about 4km, then have a quick bite to eat and hop onto my bike for five hours, then run 1 hour off the bike.
The first 30km run in this block was very taxing. I averaged 4:18/km and it was very challenging at the end. This made me certain that a great deal of my problems in Kona stemmed from a lack of endurance. The same was true of my first long ride / long day. I averaged 231w for the ride, and nearly fell off the bike afterwards it hurt so bad. The run off the bike was also quite challenging, as I averaged 4:19/km.
Endurance progressed very quickly from there. In my next long run I travelled 35km at an average pace of 4:04/km. I felt pretty good through 28km. In my next long ride / long day I averaged 255w on the bike. Admittedly, I still had a major lull around 3 hours, but by 4 hours I got through it and the 5th hour was significantly easier. My hour run off the bike had improved as well. This time round I averaged 3:59/km and yet it felt easier than the last time.
In my final long run I travelled 40km at an average pace of 3:57/km. I didn’t have a lull until about 35km this time. On my final long ride / long day, I held 261w for 5 hours, and there was close to no lull the entire time. Once again, the run off the bike felt even better than the previous time, and yet I ran 3:56/km, which was 3 seconds per kilometer faster than last time. It was at this point that I started to feel confident that I would be able to put together a much better race in Arizona than I did in Kona.
In Arizona I was able to hold good power for about 3.5 hours. Unfortunately, my endurance started to wane and for the final 35 minutes I averaged 280w, which is about 30-40w less than my target. On the run I was able to hold pace for about 16 miles. Up until this point I was averaging 3:45/km. Unfortunately, my endurance started to wane and for the final 10 miles I averaged 4:06/km. Both of these performances were significant improvements on Kona, but both still were not perfect. This is to be expected though as I only had 5 weeks to work on improving my endurance. I think with one more 5 week stint, I could have got into the best possible shape my current system would allow.
If you have been following along for a while now, you will recall that my major lesson from Kona 2015 was that spending lots of time at race pace does not make race pace easier. My conclusion was that spending time significantly above race pace and the remainder of the time significantly below race pace, is what makes race pace easier. I took this conclusion one step further in 2016 and decided that in order to get my intervals as high as possible above race pace, I was not going to do any sessions with unnecessary levels of volume. Since I was focusing on the 70.3, the necessary volume was 2 hours on the bike and 20 kilometers on the run, as this is the time/distance covered in the race. I still think this is the best way to prepare for a 70.3, and even an Ironman.
Doing long bikes, runs and days throughout the year puts unnecessary fatigue into the body. That fatigue will show itself in your high-end interval workouts, and you will not be able to push the upper limits as high as you could if you were not doing those long sessions. Once the body is in good shape I don’t think it takes long to build endurance. I think it takes about 10 weeks to build up the volume to the point where you will be able to RACE an Ironman from start to finish, to the best of your ability.
In summary, I think the best way to prepare for an Ironman is to focus on pushing the upper limits as high as you can get them for most of the year. If I was preparing for Kona for instance, and I started training on January 1st, I would spend the vast majority of January through to the end of June focusing on pushing my Vo2Max and Lactate Threshold paces. And then, around mid-July (about 10 weeks before Kona), I would continue to push those upper limits, but I would then start systematically increasing the volume of my long run, long ride and long day. The hope for this phase of training is that I can eventually exercise for the duration the Ironman will take me, without much taxation. You must keep in mind though that once this phase starts, it is very unlikely you will be able to produce the same Vo2Max and Lactate Threshold paces because you are introducing a lot more fatigue into the body due to the increased volume. But, it is still important to work these upper values. Once again, I think it is very important to stress that these long sessions are very little about pace. They are about stimulating the muscles for the duration you plan to compete for, so that in the race, they will continue to fire properly from start to finish, allowing you to RACE an Ironman from start to finish.
There are two more valuable lessons I learned in the five weeks after Kona that I think may be of value. I will present these in my next post.