An Ironman marathon is not the same as a stand-alone marathon. In this race, your performance will depend on how well you have dealt with the 3.8km swim and 180km bike, before you’ve even run a single step.
So what does it take to produce a successful IM run? Like a regular marathon, training, planning, nutrition, pacing and mental strategies all need to be considered – but now in the context of a multisport race.
Training for an IM-distance race can be split into two aims: cardiovascular fitness and muscular endurance.
Building cardiovascular fitness involves getting your heart capable of beating at the desired rate for the duration of your event, and then working effectively at that rate. So use any opportunity to develop the fitness of your heart and lungs. This doesn’t have to be discipline-specific, but it does take time. For most people the easiest way to do this in a consistent, injury-free manner is on the bike.
Secondly, you should focus on increasing muscular endurance, building muscles that can produce the required power for the duration of the event. For an IM run, this involves getting the running muscles used to working effectively after 5-9hrs of use, when already fatigued.
The 3hr run, that staple of marathon training, isn’t so useful in this situation. You’ll need to fatigue your muscles before you begin run training, so that you can practise running tired, but at the same time you need to minimise the risk of injury.
Training is your chance to formulate your plan of attack for the race. Come race day you should know what you’re doing and when with regard to pacing, nutrition and ‘unexpected events’ such as a puncture or other disaster. Come up with a plan and practise it.
When it comes to nutrition, the bike ride is key to the success of your Ironman run. Aim to take on 60-90g of carbs per hour, tailored to your own needs based on experience gained in training and previous races.
Ride at a pace that allows you to take on enough nutrition without using up too much carbohydrate, leaving sufficient for the run. Riding too hard will reduce blood flow to your stomach, thus reducing the absorption of carbohydrate; the excess is left bouncing around your digestive system on the run, potentially causing stomach issues later on.
In most IM-distance races, those at the quicker end of the field spend proportionally more time on the bike than the run, whereas those who finish later spend more time on the run. So for a quicker time overall, you may actually need to go easier on the bike.
In training you will learn the pace you should maintain for the run. Setting off too quickly will mean a drop-off in pace towards the end. A run-walk strategy can help: running for a set duration before walking for a distance can actually leave you running much further. Consider walking though the aid stations and taking on valuable nutrition at the same time.
Confidence and determination will see you through the tough patches in a race, and their power shouldn’t be underestimated. There are plenty of strategies to choose from, including reciting a mantra or mentally rehearsing your race, but perhaps the easiest is to break down the main goal into smaller parts.
Use aid stations, mile markers or times to focus your mind and energy on the ‘now’. Achieving each of these smaller goals helps you on your way to the ultimate goal of crossing the finish line.