Ian O'Riordancompares his fitness with that of the Kilkenny hurler Eddie Brennan on a visit to the Leinster Sports Clinic in Portlaoise

EDDIE BRENNAN has just completed the resting metabolic test, and is told the results are excellent - his carbohydrate-to-fat-burning ratio is in the range of a highly trained elite athlete.

"Really?" he asks. "Does that mean I can eat more chips?"

A short while later, Brennan almost falls off the stationary bicycle having effectively pushed himself to his physical limit to establish his V02 max, the standard measure of how efficiently oxygen is delivered to the muscles, and the best indicator of an athlete's cardiovascular fitness and aerobic endurance.

It is measured as millilitres of oxygen used in one minute per kilogram of body weight - and he hits 58.9 ml/kg/min. It's not quite Lance Armstrong territory (his was 85 ml/kg/min) but Brennan is nonetheless running off a highly efficient engine.

"I won't . . . have . . . anything left for training tonight," he says, still catching his breath.

Brennan, obviously, is only playing around. The last thing he'll be doing is eating chips just a few days before the Leinster hurling final against Wexford. There's been no let-up in training this week, and no excuses either.

Brennan, like all his Kilkenny team-mates, is a dedicated and disciplined athlete, who also happens to be a hurler. Whereas hurling was once a game of skill with the option of fitness, there's no room for the physically faint-hearted anymore - and Brennan has a reputation for being among the fittest around. He also didn't earn the nickname "Fast Eddie" for nothing.

To find out just exactly how fit he is, Brennan has come to the Leinster Sports Clinic, which the husband and wife team of Chris Simpson and Deirdre Woods set up in Portlaoise six months ago.

The idea was to provide a scientific evaluation of the specific aspects of physical fitness to a greater range of athletes, given such evaluation is largely limited to those attached to the high-performance labs of the national universities.

Having initially attracted mostly runners, swimmers and triathletes, the clinic is now looking towards field sports, on the basis that even the club hurler or footballer can benefit from the tests provided, to train more efficiently and more sensibly.

Simpson specialises in the metabolic assessment and exercise testing, while Woods, who two years ago represented Ireland at the World Triathlon championships, does the biomechanical assessment and video gait analysis.

For comparison purposes, they also perform the tests on me. Even with my distance-running background, the expectation was that Brennan would show far superior results, amplified by the seven-year age difference, although this wasn't always the case. As in any physical, impact sport, hurlers don't necessarily want to fill every recommendation for a fit, healthy body.

Brennan takes his overall fitness very seriously. On top of the standard three-days-a-week with Kilkenny, he'll hit the gym at least twice a week, and has always been careful to fully stretch after each session and ensure he's always giving his body ample recovery. He watches what he eats, very carefully. So, there were a few surprises when Simpson wires us up to the Bodystat 1500, which measures body composition. Brennan shows a body-fat content of 14.8 per cent (compared to my 13.7 per cent), and a body-mass index of 25.3 (compared to my 20.5) - which by generic standards classifies Brennan as marginally overweight.

"The body-mass index doesn't apply to an athlete the same way it does to a normal person," explains Simpson. "In Eddie's case, there is clearly a lot of upper-body development, and that's what increases the overall body mass. The majority of rugby players these days would be classified as overweight on the body-mass index, when clearly they're not. Martin Johnson was actually classified as obese.

"More importantly, Eddie's hip-to-waist measurement is 0.82, below the recommended 1.0, and that's a more important indication of a lean body. The body fat content also needs to be a little higher for an athlete in an impact sport like hurling, to provide the internal organs with protection, and also the joints. Eddie's is still quite low at 14.8 per cent, and he would not want to drop too much off that."

Hurling, it would appear, is no sport for the lightweights anymore, and a player of light build is possibly at a greater risk of sustaining injury.

"I've been very lucky all right with injuries," says Brennan. "Beyond breaking my collarbone back in 1999, I've had nothing serious, and maybe only a dead leg here and there. And I think the days of hurling with any kind of injury at all are over."

Brennan is sceptical of some of the new-wave injury treatments (he tried cryotherapy and wasn't convinced) but seems intrigued by the biomechanical assessment provided by Woods. She puts him through various foot scans, identifies a couple of minor faults, and then produces two freshly moulded shoe inserts - or orthotics - which he promptly places into his boots.

"He has almost no toe contact with the ground whatsoever and also shows collapsed arches," says Woods. "But he has no gait issues, and this wouldn't be impacting on his performance. The orthotics improve overall body stability and therefore help to prevent the onset of injuries. This is only slowing catching on in Ireland, but the entire Australian rugby team are fitted with orthotics as standard, simply as another insurance policy against injury."

Then it's on to the resting metabolic test - which breaks down calorie consumption and helps identify what the athlete should and should not be eating.

"I've been looking forward to this," says Brennan.

It means lying undisturbed for 15 minutes, with a gas mask on, and once again the results weren't exactly as expected. Brennan's resting metabolic rate (RMR) equated to 1,866 calories a day; what he needs to maintain body weight outside of any physical exertion. Mine was 1,902, despite my being almost 10kg lighter - and apparently my parents can be thanked for that.

We showed an identical respiratory quotient of .80, which means, at rest, we both used fat oxidation as our main source of energy. "This is what you'd want to see in an athlete, the result of the recovery and adaptation to training" says Simpson. "It means, at rest, the body is saving carbohydrate, which of course will be the main source of energy once exercise begins."

So to the real test: the V02 max. Theoretically, the more oxygen used during high-level exercise, the more ATP (energy) produced - and while this is vital in endurance sports, it can also play a big role in a 70-minute, non-stop game like hurling.

To determine this, we must both produce an all-out effort over 15 minutes of exercise, as Simpson gradually increases the speed and intensity, and a gas mask measures the volume and oxygen concentration of inhaled and exhaled air. We're also fitted with a heart-rate monitor.

This can be done on either a treadmill or a stationary bike. Simpson prefers the bike, simply because it's harder after an all-out effort to fall off a bike than a treadmill. Either way, it looks like we're plugged into a heart-attack machine.

The average, untrained person has a VO2 max of 45 ml/kg/min, and despite Armstrong's frightening figure of 85 ml/kg/min, even those with years of training don't usually get any higher than 60 ml/kg/min.

"We could be here all night," says Simpson, as Brennan starts revving it up. The latter looks extremely comfortable as the intensity is gradually increased.

"Drive it on, Eddie. Really push hard." Brennan keeps pushing until Simpson is sure he has reached his peak. It took slightly over 15 minutes, a reflection of Brennan's vast reserves of power. His heart-rate went up to 154 beats per minute, and his VO2 max of 58.9 ml/kg/min is well above average.

So, when my VO2 max comes in at 66.3 ml/kg/min, Simpson has some explaining to do.

"VO2 max tells you a lot about oxygen efficiency, but of course it doesn't tell you everything. Eddie was riding with a lower cadence, was delivering much more power, and was able to sustain that all the way through.

"He still has an excellent endurance base, and his engine is nicely ticking over, but for a game like hurling, it's more about being able to recruit the fast-twitch muscle fibres, which he is very efficient at doing. It's about having the endurance base, but being able to sprint off of that."

It had also taken Brennan 13 minutes to reach his aerobic/anaerobic threshold, the point where his maximal muscle power output was no longer efficient, whereas mine came after nine. His heart-rate at that threshold was 126 beats per minute, and mine was 134. So Brennan was far more efficient at a higher intensity. He might not beat me in a marathon, but he'd kill me in a sprint.

One of the main benefits of the test is establishing the aerobic/anaerobic threshold, and for Brennan, that means his heart-rate threshold of 126 beats per minute is crucial in maximising his training.

Ideally, he would allow his heart-rate to fall below this threshold after each period of sustained exertion, to ensure proper recovery, and prevent any onset of chronic fatigue. But that, perhaps, is for the truly professional era of hurling.

It may only be a matter of time before VO2 max testing and the like is standard practice in intercounty hurling.

Luckily for me, they don't have any standard test for hurling skills. Brennan might well have broken that machine anyway.

Eddie Brennan
Age: 29
Height: 1.82m (6ft)
Weight: 84kg (13st 3lb)
Fat: 14.8 per cent
Body Mass Index: 25.3
Hip-to-waist: 0.82
RMR: 1,866 Kcal
VO2 max: 58.9 ml/kg/min
Peak heart-rate: 154
Heart-rate threshold: 126
Peak work (Watts): 150

Ian O'Riordan
Age: 36
Height: 1.78m (5ft 10in)
Weight: 65kg (10st 3lbs)
Fat: 13.7 per cent
Body Mass Index: 20.5
Hip-to-waist: 0.72
RMR: 1,902 Kcal
VO2 max: 66.3 ml/kg/min
Peak heart-rate: 150
Heart-rate threshold: 134
Peak work (Watts): 140