Lab rat: Tim Noakes may have his critics but his researchers are certainly thorough. Ouch: Lab researchers took a pea-sized chunk of meat out of each of Craig McKune’s thighs to measure carbohydrate usage during riding. (David Harrison)

I was a Tim Noakes guinea pig

Craig McKune
The sports scientist’s research team doesn’t shy away from pushing the body to its limits.

On a cold June morning, I handed my body to Tim Noakes’s laboratory. His team starved me and laced my evening water with stuff that caused me to become giddy and fall over my cat.

They had me out of bed at 5am, sucked a chunk of muscle from my thigh with what looked like a medieval torture instrument, sat me on a stationary bicycle, sunk needles into my arms and strapped a gas mask to my face.

They had me pedal uncomfortably hard for two hours while measuring gases passing in and out of my face and draining vials of blood from one arm and dribbling a solution into the other.

They took another piece of muscle, this time from my other thigh, and sent me home with a bit of petrol money and a pleasant: “I hope you enjoyed it.”

I did, actually.

Scientific fascination 
You see, science fascinates me, although Noakes’s manner of communicating science irritates me. I’m obsessed with riding bikes and racing them and, because I eat mainly vegetarian, I passionately consume lots of carbohydrates.

I was sold when I heard one of Noakes’s research team on talk radio: they were looking for strong cyclists who ate either very high or very low carbohydrate diets.

I was interested to get a look into the workings of a lab run by Noakes, a sports and nutrition scientist who had told a room full of people: “If you eat a high fat diet all your life you will not develop diabetes; you will not get cancer; you will not get dementia; that I can guarantee you.”

I emailed his Exercise Science and Sports Medicine research unit at the University of Cape Town and researcher Chris Webster called me back immediately. I was a good high-carb candidate.

By the next day, he had me logging every mouthful of food and three days later I was in their laboratory in Newlands, where he meticulously captured the proportions of each meal on his database.

Athletes and carbs
Traditionally, athletes favour high-carb eating. The carbohydrates are stored and the energy easily accessed by the muscles and the brain while training and competing.

But these stores don’t last long in a race, so some athletes are cutting down on foods such as bread, pasta and potatoes in favour of meat, dairy, eggs and oils.

Webster said: “The idea behind high-fat eating is to increase reliance on fat and the ability of the body to use fat at higher intensities.”

He explained to me how every morning his housemate, who follows the Noakes eating plan, breaks an egg into his coffee and adds a blob of cream and a knob of butter, which he whisks into a froth.

“It’s actually quite delicious,” Webster said.

People who eat like this will derive much of their energy from their stores of fat. Aside from benefits such as weight loss, there might be certain performance benefits for “fat-adapted” athletes.

Noakes, for example, has said that he ran the Old Mutual Two Oceans Half Marathon on coffee and a slice of cheese for breakfast and a small snack later.

For a comparable race, I would drink a date, banana, almond, honey, yoghurt breakfast smoothie, suck down several horrid syrupy sports gels and drink one or two bottles of sports drinks.

Carbs as a "crutch"
Noakes has said people who eat like me are “carb-adapted” and “metabolically crippled” – our taste for carbs is our “crutch”.

But the evidence is inconclusive on the question of exactly how and when the slice-of-cheese approach might be helpful for sports performance.

The trial I signed up for was not attempting to answer this. Rather, Webster and team are seeking to understand the more detailed nuts and bolts of how the bodies of athletes on the different diets access energy. Separate studies of performance in sport are expected to follow.

For my first day in the lab, Webster tested my “peak power output” and a few other metrics.

Propped on a stand in the middle of the clean linoleum floor was an old steel-framed racing bike, its rear wheel attached to a device wired to a desktop computer.

The device puts pressure on to the rear tyre, making it harder or easier to pedal. I was to pedal while the device pressed harder and harder until I could pedal no longer, thus measuring the power of my legs.

A man-sized fan stood directly in front of the bike, ready to pour cool air over my struggling, sweat-drenched body.

“You will get to a pretty dark place before it ends,” Webster said.

I did.

Testing
On the Friday morning before the trial, Webster took a blood sample and handed me a bottle labelled “D2O”. This was deuterium oxide, which is like water but its hydrogen molecules are heavier.

While my friends headed off to the beer taps that night, I was told to stay home, eat dinner before 7pm and consume only this stuff in small sips between 9pm and 11pm.

The deuterium molecules were to assist the researchers in analysing how my liver produced glucose as I pedalled the bike for two hours the next morning.

I downed the whole bottle at 9pm, went to bed, woke at midnight, tripped over the cat, fell asleep and arrived hungry at the lab at 6am the next morning, my blood laced with deuterium.

The lab buzzed with activity.

Webster hustled me to a plinth, my bed for the next two hours, where he set up an automated syringe that would dribble a deuterium glucose tracer solution into my blood stream for the next four hours.

Doctors collecting data
Hunched over a side bench, Tertius Kohn, a doctor of biochemistry, set out vials, petri dishes and liquid nitrogen. He would handle chunks of my thighs, to give the team ­information on how much stored carbohydrate in my muscles I used while riding.

In another corner, Jamie Smith, a doctor of exercise science, fiddled with the wiring of what looked like a top-loading washing machine – a centrifuge.

Webster later explained this: “The centrifuge separates the plasma, or serum, from the cells within the blood sample. We are interested in plasma metabolites, hormones and tracer, so we spin the sample and discard the cells. The remaining plasma or serum sample is then stored for later analysis.”

As I lay there, the team’s physician and meat collector, Jeroen Swart, strode through the door.

He pulled on latex gloves, sliced open my thigh with a scalpel and told horror stories of gnashing bones, spilt blood and people collapsing on the floor at the sight of his biopsy “needle”.

Swart hauled out a thing the size of a screwdriver. A clear tube attached to the back of this needle led to a suction device operated by Kohn.

Swart rammed the needle through the incision he’d made. Kohn sucked. Out popped a pea-sized piece of my leg. Kohn smiled and hurried it to his petri dish where fog swirled from his case of liquid nitrogen. The procedure is known as a muscle biopsy.

Back on the bike
Quivering, I climbed on to the bike and began to pedal for a tough two hours, after which Swart returned with another needle and a sadistic smile.

A few days later Webster had me drink a mega-sweet glucose drink and took more blood samples, and then I was done. The researchers are still finalising their results.

Recently, after racing our bikes through the mountains of Stellenbosch, some friends and I sat at a sticky plastic table, shovelling down boatloads of pasta and draining beers.

“Hey Tim Noakes! I eat what the fuck I want and I’m not fat, because I ride my bike every day!” spat my overexuberant friend Guy, beer froth dripping from his moustache. We all agreed, and bashed poor Noakes for a few more minutes before moving on.

I think Guy is right that all you need to do to stay thin is to exercise and eat generally wholesome food – but maybe Guy and I are just genetically predisposed to being skinny weeds no matter what we do. And I suppose I should concede that it is not normal to ride as much as we do.

Without statistically useful evidence at hand, I can make no claim about what one should eat for whatever goal. For those who do make such claims, I’d like them to have great evidence on which to base them, which is why I jumped at the opportunity to contribute to the generation of knowledge.

It was a fascinating experience. Depending on the size of the needles, I might not say no to joining another trial with this team.

Craig McKune works for the M&G Centre for Investigative Journalism, amaBhungane. The results of the trial in which McKune participated are not yet available

Tim NoakesBanting dietcycling

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