Brussels lab tests the limits of the human body

It is in the name of science, research and public understanding that I have agreed to become a human guinea pig. Or, at least, that is what I tell myself as I pedal manically on an exercise bike, while eight electric wires grasp my torso, a mask clasps my nose, and a nurse leans over my shoulder every three minutes to draw blood from my ear.

This might sound like a mise-en-scène from The Hunger Games, but it is actually one of the world’s most serious and sophisticated research operations into sports. The Brussels Laboratory for Exercise and Top Sport (Blits) is pioneering studies into what exactly happens when we huff and puff around the track, across the pitch or through the pool.

“We’re looking into the many ways in which exercise changes us,” says Blits director Romain Meeusen. “There is still a lot to learn about how the body responds and adapts. And how we can train more efficiently.”

Blits is based in the newest building on the campus of the Free University of Brussels (VUB) and is part of the Human Physiology Research Group (MFYS), which looks at broader physiological issues. Meeusen, who also heads the MFYS, oversees a group of 25 researchers, while also delivering lectures on exercise physiology every week.

Hooked in

“We do research, and we also help people improve their training regimes,” Meeusen says, referring to the factors from biomechanics and biometrics to body mass index (BMI) and maximal oxygen uptake capacity (VO2max). “Our laboratory can test what happens to your body when you do sport, from your heartbeat to the way you process oxygen. And we can see what exercises are most likely to improve your strength, and which ones are least likely to cause injuries.”

Meeusen is keen to demonstrate the depth of data that his team can scour, so he arranges training sessions for me, the first of which is the electric hook-up and blood drain.

After an initial half hour of questions, inspections of my body and movement analyses, I am sent to the testing/torture chamber. The wires are connected to an electrocardiography (ECG) machine to measure my heart, while the mask monitors my oxygen intake. The blood samples are to measure lactate, which is a by-product of glucose used by muscle cells.

As I padal the exercise bike, the resistance is raised every three minutes, at the same time as my ear is pricked. What starts out gently enough soon becomes a grind, and I’m forced to stand up on the bike.

Sweat (and blood) drop down onto the bike’s base and the floor. A half hour of wheezing later, when I can no longer keep up the speed, the exercise is stopped.

After my shower, an assistant, Jo Verschueren, presents me with a 15-page dossier explaining my test results. The lactate checks are markers to show how the body is adapting to exercise.

“If you can use the oxygen you inhale, you don’t accumulate much lactate,” Verschueren explains. “But when the exercise becomes too intensive and you don’t have enough oxygen, the lactate begins to build up.”

In my case, the lactate production grew almost exponentially. I began at 80 watts – effort level is expressed in watts – with a starting heart rate of 63, and ended at 290 watts, with a heart rate of 141. Verschueren generously describes me as among “excellent oxygen uptake” people.

“You are a big person, but you also have big lungs,” he says. “If you have low capacity to inhale oxygen from the air, you have a Fiat engine. In your case, you have a Ferrari engine.”

Like hitting the wall

In between, they found my aerobic threshold, crossed when my heartbeat reaches 115, and my anaerobic threshold, when it’s at around 135. The anaerobic threshold is the level of exercise intensity at which lactic acid builds up in the body faster than it can be cleared away.

This is what marathon runners call bonking, or hitting the wall. Or, as Verschueren says: “There is a man with a hammer who says, ‘Stop, this is enough!’”

The second cycling session, a few weeks later, is mercifully free from clamps, masks and needles, but is equally gruelling as I try out the new Blits altitude chamber, a special testing room that is used to simulate low-oxygen environments. My exercise is managed by Lieselot Decroix, a 2008 Olympic road racer who is a professional rider with Lotto Soudal Ladies.

The chamber is a small, air-tight room, where the atmosphere is controlled through powerful vents. Rather than suck the air out – an operation that would require a room with reinforced walls – they simply pump more nitrogen in.

“Many people come here thinking, ‘Oh, this will be easy!’ And then they start exercising and find it’s really hard work,” Decroix says.

That is indeed how it feels: the effort level at a constant 130 watts is relatively light on my legs, but speech soon becomes difficult, and I struggle to complete sentences.

Decroix explains that this effect – easy on legs, harder on the heart – is useful for recovering athletes as they can exercise their cardiovascular systems without straining the muscles. Over a 45-minute period, the “altitude” rises slowly from 3,000 metres to above 5,000, which is the elevation of Everest North Base Camp in Tibet. By the end, I am drenched in sweat.

There is a significant body of evidence that the Kenyans and Ethiopians who dominate middle- and long-distance running have been aided by their life and training in the East African Rift. Decroix says this certainly helps, although she admits that it is hard to isolate the altitude from other mental and physiological factors.

Meeusen is particularly fascinated by the mental and physiological issues associated with exercise. He points to a recent study by his team on whether exercise could improve cognitive recognition.

Test subjects in the altitude chamber did quizzes on the computer while the oxygen content and humidity changed and the temperature varied from five to 45 degrees Celcius. The tests took place before and after, and even during exercise on the bikes.

Some of the experiments relate to mental fatigue: Volunteers have to do really boring tasks for 90 minutes. “After that, their physical performance decreases,” Meeusen says.

Cycling can save the world

Another study looked at sustained military operations, aiming to replicate the missions that last for more than 72 hours. During these operations, soldiers have to concentrate for long periods of time, but they also have be able to make crucial decisions quickly.

So how can these perceptions of fatigue be altered? Coffee, Meeusen says. “Caffeine enhances performance. We have tested it; you not only get less fatigued in your legs, something also happens to your neurochemistry. People who use caffeine perform better. But the effect of caffeine is in the brain; it’s not that you burn more fat.”

The technical explanation for this is that it antagonises a neurotransmitter, and therefore stimulates your attention. Meeusen even did a test where volunteers just rinsed their mouth with coffee and then spat it out. “Even with that, their brains lit up, and they performed better.”

This also works with energy drinks like Red Bull, which contain caffeine, taurine and glucose. “And you don’t need a high dosage,” he says. “Two espressos are enough.”

Other research looked at the effect of pollution on the brain. “Many people go jogging around Warandepark and Jubelpark, but these are some of the most polluted places in Brussels,” Meeusen says.

Most of the research, however, points to the benefits of exercise. One study recommended that children cycle to school, as it can reduce the risk of cardiovascular diseases, diabetes and hypertension, which are among the leading causes of death and disease.

The same study also shows that cycling is a means to reduce traffic congestion, air and noise pollution and the consumption of fossil fuels. Encouraging cycling or physical activity in general at young age is important, the study adds, as it increases the probability of being physically active during adulthood.

And this ties in with Meeusen’s overall view: Sport serves both the body and mind. “We are looking at the effects of exercise on the body, and how different conditions produce different results,” he says. “But there is no doubt that sport is almost always good for us.”

Photo courtesy VUB