Cam Wurf seems to have a real problem with backing up his uber bike with sustaining the 4min/km pace for the whole marathon that is his strategy to run 2:50.
It takes a long time to build the running strength to hold on in the back half of a an Ironman marathon. Atheletes who mange to do that shortly after taking up Ironman usually have a decade long (or more) history of long distance running. Witness Craig Alexander. His long day was 30km in the morning, backing up with another 12km in the afternoon. He did that for a decade before switching to Ironman.
Cameron’s approach is to treat most of his Ironman races as ‘catered’ training days and he does about 8-9 such races a year. The problem seems to be that regardless of whether he is doing a ‘training day’ ironman or a targeted race he is stuck at around the 3 hour mark for the marathon. Each one he starts off at 4min/km but at some stage the wheels fall off and he crawls home in just over 3 hours.
He needs a new strategy. Perhaps do way less Ironman races each year. Say 4. For two of them, treat them as training days BUT don’t go au bloc on the bike. Sit up in the second pack of pros and aim to run through the field staying strong for the whole marathon. Get his body used to that feeling at being below or at 4minute pace the whole way.
the other thing is that, certain freaks aside, running a fast Ironman marathon is not a linear process. Van Lierde ran well the whole way last night for a 2:44 marathon split. He started off at 3:49 pace, but this slowly slipped to bang on 4 minutes for the last 5km. Cameron wants a 2:50 split I think he needs to go out in 3:55 pace for the first half and learn to hang touch at no worse than 4:05 for the second half. Taking it super easy on the bike for the next couple of Ironman races until he achieves that 2:50 split should be his goal.
i think he has IM Sweden and Wales on his calendar before Kona. Sweden especially would be an excellent race to try that strategy.