Ironman - Part One

The biggest race in the world of triathlon is still the Ironman in Hawaii every October. With such a super-fit breed of athlete turning up each year the sports scientists have a field day.




The carrot of running down Alii Drive to break the Kona finish-tape motivates many triathletes to train for hour, after hour in an effort to qualify at one of the many sanctioned Ironman qualifier across the world.

Meanwhile, sports scientists are always looking for an ultra fit breed to study, prod and measure, in an effort to expand our knowledge of the human body and its response to exercise. When the two groups meet you get "LabMan", the sports science "study", with plenty of academic brawn, each year based at the King Kamahamaha Hotel.

Historic Kona Lab-Rats

Back in 1985, the researchers, headed by the energetic and respected Dr. Mary O'Toole studied Ironman competitors and their bike leg performance (1). However, it was not until 1989 that this appeared in a respected journal, and now, over 12 years later we finally let it arrive at the eyes of those most likely to gain from it: Ironman triathletes!

However, although you may never start or train for an Ironman there are many lessons which can be learned from the study and its conclusions. What ever your aspirations read on...

Science meets Ironman

The researchers found twenty four volunteers (14 men, 10 women) who then performed a cycle test, pre race, so that the average group fitness level could be calculated for aerobic fitness, lactic acid production, breathing rate and cycle power. This would then be compared to cycle race time to gather an insight into the relationships and best ways to tackle the bike leg of an Ironman.

THE TEST: Two weeks before the race each athlete rode a lab cycle machine at various, progressively harder work loads (80 up to 340 watts) in order to measure their heart rate, level of lactic acid in the blood and oxygen usage. After 3 minutes the wattage was increased by 40-80 watts (depending on point in the test) until the athletes could no longer keep the level of power output required.

The average data, with minimum and maximum in brackets, for the athletes characteristics and their cycle data are shown below: VARIABLE MEN WOMEN
Age (yrs) 40/31 (26-62) (19-50)
Height (m) 1.80/1.71 (1.67-1.95) (1.56-1.87)
Weight 73.7/58 (62-89) (48-73)

Finish Time (h:min) 12:22/12:36 (10:32-15:50) (10:48-14:59)
Cycle Time (h:min) 6:21/6:24 (5:39-7:30) (N/A)
Peak VO2 (ml.kg.min) 57.4/57.5 (46-70) (49-65)
Peak HR. (b.min) 173/178 (151-188) (158-191)
Peak cycle power (watts) 340/304 (280-440) (240-360)

What the data means

When the numbers where "crunched" by the University of Tennessee computer several interesting results were found. Firstly, the athletes maximum oxygen usage (as measured on a lab bike; VO2) was inversely related to bike time, so a fitter athlete (higher VO2 max) has a lower bike time (faster rider). Considering the variation of ages (19-62) this is not an amazing prediction: older athletes=lower V02=slower cyclist. However, the next conclusion was not obvious: heart rate at the athletes lactic acid thresholds measured was not related to bike time.

So, despite some coaches and scientists hailing lactic acid measurement as the great messiah, it seems that in ultra-endurance athletes, the use of lactic acid measurement across a wide group of abilities does not predict how fast they are going to ride the Hawaii Ironman bike leg.

Those who have pedalled at a 45 degree angle on the Queen-K will attest to the fact that Ironman cycling in Kona is not just about fitness but also: the weather, how right you get your feeding and drinking and, very basically "can you pee and spin at the same time".

One comment which must be added to this whole article on Ironman research in 1985 is that rules and technology were different. You could enter Ironman, with no experience and race - Ironman qualifiers (I.Q's) had not yet begun.

Additionally, aero- bars were four years away as were aerodynamic drink systems, clipless pedals, aero wheels and exotic bike frame materials. Cycling was hard in 1985, that's if you can call the Kona course "easy" these days, which it definitely is not.

Note: Hawaii virgins realise this when the 4000 feet worth of climbing over the 112 mile course hits you in the face. Especially, the "grind" at 111 miles up an unfortunately placed steep mini-hill.

But what of the modern day Iron-person, how can you get faster and what sort of training should you do? Here's a secret or two...

TAKE HOME LESSONS FOR THE IRON-PERSON

Get Aero (and comfy)

At a given wattage output (the study athletes were putting out about 230 watts) you go faster if you and the bike are more slippery through the air. However, extreme positions, and lack of practice riding in your race position often results in lost time standing up, stretching-out and cursing the Kona gods that you are hot and uncomfortable.

Forget lactic

Training above your lactic threshold, for most that will be somewhere between 75 and 90% of there maximum heart rate, has very little benefit. So, use nose breathing, sensing of your exercising muscle status (Does it feel like lactic acid is building up?) and go for the Ironman experts rule of thumb:

train 95% of time at an aerobic pace (180-your age), plus 5% just over this aerobic-level.

Finally, race conservatively on the bike, or its a long death-march from mile 9, just outside the town of Kona, to the energy lab, and back!

Heat

Many races force the Brits to realise how much heat acclamation could help you on your next visit. Although sauna jogging has been done the keys to Ironman thermal regulation are: get there 10 days early, use glycerol to hyperhydrate beforehand and on the bike (Factsheet available) and drink on the bike so that you pee at least once an hour.

In Kona this can mean a litre or more per hour, so get used to drinking lots in training. Things not to try: teaching your body to survive without water in training, using sweat suits or ignoring aid stations in the race so you can keep you pace up. Doh!

Long

Train long to get you and your backside familiar at being in the saddle for many hours. This means a progressive increase from 2-3 hr. rides up to 5-7 hrs., most likely alternating a "5" one weekend and a "7+" the next. But keep the pace and feeding at point that no grannies on shopping bikes overtake you.

Feed

Getting calories down your gullet is the key to keeping the speed in hours 5, 6 or even 7 up to level close to hours 1,2 and 3 of the bike split. Carbo drinks and even complete liquid meals* plus the occasional fatty food and treat-food keep you fed and sane. A new carbo+fat polymer looks likely to supersede the mixing of M.C.T. (super fat) into energy drinks or downing M.C.T. capsules, a la M. Allen (2). There is already evidence that M.C.T.'s make a useful addition to endurance athletes sports drinks (4,5).

Golden Nugget for those that have read this far...

Mike Pigg spilled the beans once (2), admitting that many of the pro's are using complete (carbo, protein, fat) energy drinks to get calories down. Interesting that the pro's are trying no harder than the age grouper (hr=150's for the 20-, 30-somethings) but they go just a tad faster. At 150 they can still absorb foodstuffs but stay on a sub 5 hr. pace (23-25 m.p.h.). The old saying: cruise the Ironman bike don't push it...

See Ironman PART TWO Here

REFERENCES:

RESEARCH REFERENCES

1. O'Toole, M.L. et al. (1989) Lactate, oxygen uptake and cycling performance in Triathletes. Int. J. Sports Med. 10(6), p. 413-418.


2. Beer, J.M. (1994) Personal communication, at Nice triathlon.


3. Beer, J.M. (1994) Personal comunication, at Hawaii Ironman.


4. Van Zyl, C.G. et al. (1996) Effects of medium-chain triglyceride ingestion on fuel metabolism and cycling performance. J. Appl. Physiol. 80(6), p. 2217-2225.


5. Beckers, E.J. et al. (1992) Gastric emptying ofcarbohydrate-medium chain triglyceride suspensions at rest, Int. J. Sports Med., 13(8), p. 581-584.