Thought this article might be of interest to some of you out there.
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Physiology and the Real World
By Rod Cedaro
In mid-February, about eight weeks out from Ironman Australia, multiple ITU World Cup winner and ex-world champion triathlete Brad Beven and myself decided to run an ‘Ironman Simulation Day’ in Brisbane. The objective was to take exercise science out of the lab and show aspiring Ironman participants how monitoring their bodies in training, under race-type conditions, could pay significant dividends come race day.
So at 4am, we all piled into cars and headed down to the sleepy bayside suburb of Manly, about 20 kilometres out of Brisbane . There’s a 33.3 metre pool in Manly, it’s reasonably quiet on a Sunday morning and the terrain is varied with some hills on the bike, so it posed a good location to put the aspiring Ironman participants through their paces – a 2.5 kilometre swim, 126 kilometre ride and a 24 kilometre run – all to be done at the athlete’s expected Ironman pace.
To start with, we gave the athletes very little feedback, except to turn up on the morning having had a similar lead in they’d expect during the actual race. They had to use the same equipment they intended to use on race day and practice the same nutrition plan they intended to use prior to and during the actual race.
We were surprised and pleased that on the day, we had about 20 starters, largely by word of mouth, with some triathletes actually flying up from Sydney to participate. It was emphasised from the start that the simulation was NOT a race and by and large most of the athletes focussed their energies inwards and worried about what they were doing rather than how far up the road the next participant was.
We staggered the swim, with the faster swimmers starting first and each other swimmer starting a minute behind. Body weights were taken for each participant at the start of the swim and at the end. Changes in body weight were put down to sweat losses with some athletes dropping as much as one kilogram during the swim.
Upon exiting the water, each athlete also had a blood lactate reading recorded for a later debrief. Then it was on to the bike for nine laps of a 14 kilometre loop. We recorded each athlete’s body weight after six laps of riding and recorded their fluid and energy intakes along the way. The same information was collected at the end of the ride prior to the commencement of the run.
Then it was on to the 24 kilometre run – 12 laps of a two kilometre course with weight and lactate readings taken at 12 and 24 kilometres. Brad, myself and our helpers worked furiously to record each morsel of food and drink the participants ingested during the run.
So what did we find?
There’s an old adage that says, ‘failing to plan is planning to fail.’
Nowhere is that more apparent than when preparing for an Ironman. Our Ironman simulation participants were an indicative cross-section of the multi-sport community. We had athletes aiming for Hawaii qualifying positions and we had novices in awe of the occasion and simply looking to finish at Port Macquarie this year.
Most of our participants, many of whom were facing up to an eight-hour race paced training day, started poorly by not eating enough for breakfast. One participant didn’t even have breakfast! So why is breakfast so important? It reloads your liver glycogen stores which ensures you don’t bonk from low blood glucose levels. How much do you need7 A good starting point is to aim at getting in about two grams of carbohydrate per kilogram of body weight (e.g. A 70 kilogram athlete should be eating around 140 grams r carbohydrate (-590 calories) about 90-to-12; minutes before the start of such an event.
Take home message number one – Eat adequate CHO for breakfast about 90 minutes before the start of the race.
Post swim, the majority of our participants had lost between 0.5 and one kilogram in body weight. This would have been as a direct result of fluid losses, which will eventually lead to dehydration.
Hence, take home message number two – It is imperative that athletes start drinking immediately upon exiting the water to maintain hydration and energy status. Many of our participants returned blood lactate readings well in excess of the recommended 3.0-to-3.5mM I’d suggest from a pacing perspective to racing over a 3.8 kilometre swim. In fact, one of our guys was hammering along at a lactate of 9.2mM – blow up territory if the swim had have lasted much longer.
Take home message number three – pacing is the key. While it isn’t as important in the swim because, relatively speaking, the swim is quite short and you’ll have enough stored muscle glycogen in your swimming muscles to get you through, you’re still setting yourself up for an uphill battle if you go out too hard during any segment of an Ironman. Six-time Hawaiian Ironman winner Dave Scott used to say, “The half way point of the Ironman is the 16 mile mark of the run.” So set off at a sensible, sustainable pace.
How do you know what pace to go out at? You have a couple of options in this regard. The gold standard is to get yourself into a human performance lab and have a lactate/heart-rate/velocity’ test completed. Once you have this done, a trained sports physiologist will be able to give you a heart-rate zone and pacing strategy that you should be able to maintain for the duration of the bike and run. For some, this may not be an option because of cost or convenience and at the end of the day, the information you get back is only as good as the technician you have. Your other option, which is less accurate, but provides a good starting point, would be to do some field testing on yourself. Rest up, then go out and do an hour time trial on the bike, record your average heart rate and then do the same thing over a six-to-eight kilometre run. Once you have these average sustainable heart rates, which should approximate your anaerobic threshold, aim at working between 85-to-90 per cent of these figures for the duration of the Ironman. This should give you a good starting point.
At the end of our particular simulation, a few key points came out:
1. Participants didn’t eat enough breakfast.
2. Participants didn’t drink enough fluid on the bike or run (i.e.: sweat rates varied between 800-to-1250ml per hour).
3. Participants didn’t consume enough carbohydrates on the bike or run.
4. Participants didn’t consume enough sodium during the simulation – aim for about one gram per hour.
5. Participants had no strategic pacing strategy in place, hence blood lactate readings were sometimes too low (3.2mM), which means they needed to slow down.
6. Participants had no strategic nutrition plan in place. Indeed, some of the participants didn’t start taking sustenance until three hours into the trial.
At the subsequent debrief, we sat down and went through what each participant did right and wrong and helped them formulate a plan for race day. Ultimately, that’s what you need to do – have a plan. Don’t just turn up to an Ironman without an idea of how you intend to approach the event. Remember, failing to plan is planning to fail.
Good Luck with your Ironman Adventures.
