For those carrying a little extra weight, marathon training has added perils
THE HUMAN body wasn't designed to run marathons - especially not this human body. At 20 stone - roughly 127kg - the toll of pounding out 26.2 miles on roads is substantial.
On November 2nd, 2008, in New York, I'll line up for the fourth marathon of my life, which I'm running in aid of the Cystic Fibrosis Association of Ireland. The physical challenge ahead is horrific.
"Physiologically, you burn more energy to carry that extra weight around," says Dr Brian Caulfield, head of UCD's School of Physiotherapy and Performance Science. Caulfield is a regular participant in the Dublin marathon, giving him personal insight, on top of his expertise.
With more than 40,000 steps to take in the race, the excess weight can prove quite a burden. Poor mechanics could make it feel like an extra 2,000 steps are added onto this.
"If you have to move extra load around the place, you have to burn more fuel. That's one deficiency," says Caulfield.
"The second problem is every time your heel hits the ground, you're accepting more weight through your joints," he says. "Weight does cause problems; it's longer and further into the race that you are going to notice these types of things."
In 2006, I took the rather foolhardy approach of entering the Dublin marathon, despite missing four months training with a hernia.
Wholly unprepared for the challenge, my calves turned into burning masses of pain with 12 miles still to go. Just to top it off, my left thigh joined them.
This kind of ill preparation meant that for the remainder, my walking style resembled that of Robocop. Adequate training could have prevented all this.
"Training should begin with very low mileage," says Dr Eamon Spillane. He holds a masters degree in sports medicine which included research on overweight college students and how exercise affected them.
Spillane recommends a training method mixing walking with running for those who are quite unfit. In this technique, one runs for some distance then walks then runs again.
"Building up slowly allows the tissues to grow accustomed to this new increase in activity," he says. "Failing to gradually increase exercise slowly leads to almost certain injury and tissue damage," says Spillane.
He says the potential injuries include muscle strains, joint aches or pains, tendon injuries and stress fractures of bones.
The risk is even greater when a 127kg object is involved. "Due to the extra weight, the force going through the lower limbs is greater and this can lead to increased risk of musculo-skeletal damage such as muscle strains and tendonopathy," he says.
All of this sounds rather unpleasant, but it gets worse - larger runners still have to deal with the nasty problems regular marathon entrants face. The best-known of these is "the wall".
"Like a car, our bodies only carry a certain amount of fuel," says Denise McGrath, a sports massage therapist in Milltown Physiotherapy Clinic who is currently doing a PhD in the School of Physiotherapy and Performance Science in UCD.
"This means we have an inbuilt racing limit imposed by the depletion of our muscle fuel stores, which occurs at around 20 miles," says McGrath.
Once the wall is hit, the unprepared will see their legs go to jelly and have difficulty breathing while their muscles will scream out in agony due to being full of lactic acid.
There are strategies to offset this - gel packets and sports drinks are the tools of the savvy runner to replenish energy. But the not-so-savvy might be best suited avoiding this approach.
"Gastro-intestinal stress is synonymous with marathon running, and using gels such as these for the first time during a race can tip your untested stomach to the point of no return," says McGrath.
"In the absence of training, the ambitious or foolhardy marathon runner should hope to be blessed with sound digestive organs."
If only I had the presence of mind to ask Denise about this a year ago. I boldly strode down Foster's Avenue, 20 miles into the 2007 Dublin marathon, where my darling mother handed me a gel packet.
My gut seized up immediately and the rush of the gel almost caused me to empty my stomach on the spot.
It'll also be around the time of the wall that your nipples start bleeding. The greatest advice given to marathon runners of any standard, but especially the weak, is to plaster over your nipples before the race.
The friction caused by a T-shirt or singlet while running is immense. With little difficulty, an ill-prepared runner will have a most embarrassing and irritating injury.
Luckily, despite my other foolhardy ventures, this is the one ailment not to befall me as I was warned in advance.
Despite all the pain and torment endured over the 26.2 miles, the biggest challenge facing a big man in a marathon is when the race ends - the hardest thing is stopping. Once you stop, every muscle and joint in your body immediately betrays you by shutting down or seizing up.
If you act quickly, you can freeze yourself in the pose of The Thinker, but this isn't something I'd advise. Luckily there is some good news on the recovery side.
Dr Caulfield says that my time preparing, which began in July, should make it easier for my muscles to recover.
There is still, however, the slight matter of that 20 stone. Post-race runners tend to have a voracious appetite, and it's largely down to calorie consumption.
An average weight person will burn around their calorific intake for that day during the race. The extra energy required by an overweight runner increases this burden. "You are going to burn more energy and you're going to need more energy put into your body afterwards," says Dr Caulfield.
In short, this race is going to hurt quite a bit, and once it's over, I'm going to eat my way through Manhattan.
• Emmet Ryan is running the New York City Marathon on November 2nd in aid of the Cystic Fibrosis Association of Ireland. More information on his preparations can be found online at stigforcfi.stigonline.com