As the fastest-growing sport in Britain, the triathlon is enjoying the kind of
boom experienced by running in the 1980s. Next weekend 10,000 people will
swim, cycle and run their way through personal barriers in the London
Triathlon, the biggest event of its kind in the world with the number of
entrants up tenfold since 2001. The British Triathlon Association (BTA), the
sport’s governing body, has 7,000 members and more than 100,000 take part
annually in 400 events around the country.
But are the demands of tackling three sports rolled into one just too much for
our bodies? Researchers are discovering that, far from being the ultimate
fitness goal, for many people triathlons can provide more risk than benefit
to health.
Human beings were not designed to complete triathlons, and while that is
partly why the event is such a popular challenge, the physical demands it
makes on even top athletes are extreme. Chronic dehydration, hyponatraemia
(a potentially fatal condition that can occur when too much water is
consumed during exercise), and heart and digestive problems have all been
linked to this relatively new sport. In last year’s London Triathlon a
23-year-old male competitor died in hospital after suffering a cardiac
arrest during the swimming section of the race. In 2004 a competitor died
from cardiac problems a few days after completing the event.
A phenomenon of endurance activity, in which the body shunts blood first to
the muscles and then to the skin for cooling, but fails to deliver enough to
the kidneys and intestines — known medically as ischaemia — has also arisen
in triathlons. This can lead to serious complications; one competitor
collapsed in the Hawaii Triathlon suffering from bowel ischaemia and later
had inches of his bowel removed.
Most studies into the ill-effects of triathlon competition have been conducted
in the US. At the University of Arkansas school of medical sciences, Dr
Hilary Ann Peterson, an expert in emergency medicine, coined the term
“postextreme endurance syndrome” for the adverse symptoms sometimes
experienced in triathlons. “People are suffering some really significant
injuries at these events,” she says. “We have seen only a few fatalities in
marathons so far.
But with more people participating in endurance events, and with those
participants having less experience, you have to question whether we will
see more.” Dr Peterson assessed competitors after they had completed two
Ironman triathlons — 3.9km swim, 180km bike ride and 42km (26-mile) marathon
run — in America and found that more than one third of entrants who sought
medical attention had experienced dizziness, vomiting, low blood pressure,
raised heart rate and decreased body temperature. Some had collapsed or
required intravenous fluid replacement. Her findings, presented at the
annual conference of the American Medical Athletic Association, showed that
it was not only novices or the ill-prepared who were prone to extreme
endurance syndrome; elite athletes who pushed themselves to physical limits
were one-and-a-half times more likely to suffer.
What attracts so many to the rigours of training for such events? Undoubtedly,
the sport’s profile was raised when it became an Olympic event in 2000, but
the prime motivating factors are conquering personal goals or raising money
for a charity; triathletes raised £500,000 last year. Options to try
different distances — from the more manageable “sprint” triathlon of 750m
swim, 20km cycle and 5km run to the tough-guy Ironman challenge — add to its
appeal. “People like the idea that you can break down the training,” says
Nick Rusling, the director of the London Triathlon. “They can swim before
work, cycle home and run in the evening on different days. It offers
versatility.”
Peter Holmes, a spokesman for the BTA, says that by far the largest number of
newcomers to the sport are aged 35 to 40: “There is probably an element of
the mid-life crisis and wanting to prove to themselves that they can tackle
something new.” And one quarter of the competitors next weekend are female.
Rusling believes that perceptions about the triathlon have changed. “Five
years ago if you mentioned ‘triathlon’, most people thought only of elite
athletes,” he says. “The sport has worked hard to change that image. We
wanted people to know that although Ironman events are extreme, regular
triathlons are less gruelling, more enjoyable. That message seems to be
filtering through.”
Indeed, newcomers to the sport comprise 45 per cent of entrants in most UK
triathlons, a factor that many experts believe puts them at greater risk of
suffering if they are not well-trained. Dr Michael Bergeron, a physiologist
at the Medical College of Georgia and a fellow of the American College of
Sports Medicine, says that endurance competitors, especially those below
optimal fitness, “who over-exert themselves can suffer muscle-fibre damage
that can be immediately fatal because of excessive potassium build-up in the
blood, or lead to life-threatening kidney failure”. An advisory document
written recently by Dr Bergeron for the journal Medicine and Science in
Sport and Exercise advised that “large sweat losses, insufficient fluid
intake and consequent fluid deficits could impair performance and may
increase the risk of hyperthermia (overheating) and heat injury” in mass
events.
Endurance competitors have also been shown to be at risk of cardiac stress.
Reporting in the American Journal of Clinical Pathology earlier this
year, Dr Malissa Wood, and her colleagues in the cardiology department at
Massachusetts General Hospital, found that cardiac troponin — a chemical
that shows up in blood tests only when heart muscle is damaged — rises in 60
per cent of marathon runners, and in some it rises so high that “you’d
assume these people had been admitted to the hospital for heart attacks”, Dr
Wood said. Another chemical, brain natriuretic peptide (BNP), a red flag for
cardiac dysfunction, goes up after a marathon or similar events. Platelets
(cells that contribute to blood clotting) also become activated and are more
likely to form the clots that can trigger heart attacks, and the heart’s
ability to relax after each beat remains impaired for at least several weeks
after endurance races.
Dr Ese Stacey, the medical director for the London Triathlon, says that
“over-exertion can be a problem in all endurance sports, but with triathlons
there seems to be particular risks with the swim phase of the race”. There
have been cases of both hypothermia (becoming too cold) and hyperthermia on
the same day in the London event. “The race starts early when there is often
a chill in the air, but finishes at the hottest part of the day,” says
Rusling. “Our medical team has to be prepared for every eventuality and the
weather can play a significant role in injuries and problems for
competitors.”
Dr Stacey ensures that every effort is made to alleviate physical discomfort;
hundreds of St John’s Ambulance volunteers are on hand to massage weary
muscles, tend to blisters and help cramp victims to get back on their feet.
Sports drinks and water are provided along the route. “If you are well
prepared, physically fit and have trained, there is little cause for
concern,”Dr Stacey says.
The London Triathlon will take place next weekend; visit
www.thelondontriathlon.com/
Are you ready?
- Preparing for a triathlon needs at least four months of training. Joining a
club can help as expert coaching is provided. For details visit
www.britishtriathlon.org.
- If you haven’t exercised for a while, or if heart disease runs in your family,
check with your GP before embarking on training.
- On the day consume a carbohyrate-rich meal about three hours before the race.
- You need to drink enough fluid to avoid dehydration, but avoid drinking too
much and putting yourself at risk of hyponatraemia (a potentially fatal
condition).
Dr Dan Tunstall-Pedoe, the medical director of the London Triathlon, suggests
that in endurance events of 3½ hours or more in cold weather, most
competitors should drink no more than 500ml of fluid an hour. Elite
athletes may need to drink as much as one litre an hour, depending on
the temperature.
- Because of their lower body mass, women are at more risk of hyponatraemia so
they need to be extra careful not to exceed the above guidelines.
Measuring up
Triathlons vary in distance and terrain:
Super sprint 400m swim, 10km bike ride, 2.5km run
Sprint 750m swim, 20km bike ride, 5km run
Olympic 1.5km swim, 40km bike ride, 10km run
Ironman 3.8km swim, 180km bike ride, 42km marathon
Information www.britishtriathlon.org
Reading The Complete Triathlon Book: the Training, Diet,
Health, Equipment and Safety Tips You Need to do Your Best, by Matt
Fitzgerald (Warner Books, £14.99)
