Certainty, or: Why Science Informs But Proves Nothing

FASTER by Jim Gourley

There are a few words and phrases that keep popping up in my new book FASTER, and I thought I’d take some space to address them: indicate, probably, reasonably certain.

Their importance and prevalence in the book is best highlighted by a phrase that never appears—”scientifically proven.” There is a very good reason for this, and for why you should always be wary any time you see them in a product advertisement. There is no such thing as “scientifically proven.”

That’s right. Not even the greatest scientific minds can prove with 100% certainty that something is true. Consider something as simple as gravity, for instance. On Earth, your performance in triathlon is strongly influenced by gravity, and thanks to Newton’s law of gravity we can predict that influence with reasonable certainty. But why can’t we say “with absolute certainty?” Well, as it turns out, gravity isn’t the same everywhere on the planet. It varies slightly due to the fact that the planet isn’t perfectly spherical. So we can get very close to the right answers using our established value for the gravitational constant but not the exact answer, because the constant isn’t actually constant.

The principle is even more relevant when it comes to aerodynamics on the bike. Much of the design process for modern bikes makes use of computerized aerodynamic simulations, which are based on a series of calculations known as the Navier-Stokes equations. In fact, science does not fully understand these equations or their implications. Interest in resolving these mysteries is so great that a $1 million prize has been offered to anyone who can figure them out.

You don’t  have to go to the cutting edge of science or explore black holes to find other examples of science missing the mark. The last 20 years of triathlon technology development is chock full of theories that turned out to be wrong—and crazy ideas that turned out to be right. That’s why it’s important to never be too confident nor too skeptical.

Here are just a few examples of people going too far by taking an indication as scientific proof.

6960651870_945e401694Barefoot running. This is probably the most recent example of science getting carried away. Studies by scientists found biomechanical advantages to a forefoot strike when they observed people running barefoot. The indication was that traditional running shoe designs promoted a less efficient heel strike. The “proof” people latched onto was a body of literature telling stories of phenomenal performances by Kenyan and Tarahumara Indian runners, who happen to wear no shoes at all. The minimalist shoe craze ensued, and doctors quickly noticed a sharp increase in the number of runners they saw for stress fractures and injured feet. What the running community ultimately realized is that Kenyans and the Tarahumara run on soft ground, whereas most of us are on some kind of paved surface. There is no direct causation between your footwear and how your foot hits the ground. You can adopt a forefoot or mid-foot strike as easily in your sneakers as you can barefoot. But the soles of your shoes still accomplish the same purpose their original design meant to: cushioning your foot against striking hard surfaces.

4500813971_e6ec6ef130_b2Beam bikes. Beam bikes evolved in the 1990s, the most popular of which was manufactured by Softride. The idea was that, by eliminating the seat tube, there would be less aerodynamic drag on the whole bike. That seems to have been refuted for a couple of reasons. First, the extra frame thickness required to hold the cyclist added so much weight to the frame that it appeared to negate the aerodynamic advantage. Then came the idea to form the seat tube more closely around the wheel, creating a better overall aerodynamic shape and increasing performance without the weight penalty. The idea has resurfaced in recent years, supported by advancements in carbon fiber molding that reduce the weight penalty. Whether less is more or more is more remains to be seen.

12356829754_cfa9efde61_bElliptical chain rings. Here’s another one that’s come, gone and come back again. The theory that an elliptical chain ring could somehow give a cyclist better power production has been around since people began pedaling. Shimano became the first major company to make a commercial product based on that idea in the early 1980s. However, subsequent testing (and complaints from cyclists) indicated that it was doing more harm than good. The line was discontinued and no one else tried to develop the idea. That is, until Rotor came along in the 2000s with the Q-Ring system. They changed the design from the Shimano concept and came up with some improvements in the angle between the crank arms and the “long end” of the oval rings. The verdict? Undecided. I have read 15 published studies on the effects of using different chain ring designs, and there is an almost even split between conclusions saying yes, no and maybe. I spend a great deal of free time talking to scientists about the subject, and the consensus I get is that something is happening, but we’re not sure what. This is actually a good thing, because it means there are still directions we can go to find ways to improve our performance.

Compression wear. This is another example of the enduring split decision. The idea behind compression where is that it will help to “squeeze” blood out of capillaries in the muscles and lactic acid along with it. Some research indicates that this helps in the recovery process. Many triathletes believe in the principle so strongly that they even wear the garments while racing. However, there are studies that find no recovery benefit to compression wear. That doesn’t mean one side or the other is right. Each experiment tests for different factors and therefore measures different standards of benefit. Many cases, as often happens in science, make apples and oranges comparisons. There have been observations of positive, negative, and no effects at all of wearing compression garments. Who’s right? The investigation continues.

Catch panels on wetsuits. Let’s end with a little more certainty. “Catch panels” on wetsuits are textured surfaces along the forearms. The idea behind their design is that a rougher surface will increase drag in the water. More drag on the arm is a good thing, since that is how it produces thrust. However, studies on commercial designs found that the suit isn’t able to create enough drag to make a significant contribution to a swimmer’s effort. That doesn’t even account for the theory that swimmers actually produce propulsion by lift forces rather than drag, an argument we’ll cover on this site.

Science is a tricky business, and we’re never perfectly sure of ourselves. Does that mean what you read in Faster is wrong? No. It means that it’s based on the best information we have today. From discovering the Earth is round to the existence of black holes, science is always giving us new reasons to be amazed with the universe and methods to enjoy it. Triathlon is no exception. All indications are that our human and technological performance is highly advanced, but that doesn’t mean it won’t get better. We will discover new ideas and find new ways to get faster. If history proves anything, it’s that things will change.

Of that, I’m absolutely certain.

If you’re interested in getting faster, you’ll be fascinated by FASTER: Demystifying the Science of Triathlon Speed. In Faster, astronautical engineer and triathlon journalist Jim Gourley explores the science of triathlon to see what truly makes you faster—and busts the myths and doublespeak that waste your money and slow down your racing. With this knowledge on your side, you can make simple changes that add up to free speed and faster racing.

Barefoot running photo: http://www.flickr.comphotospoiphotography6960651870sizesm
Softride photo (cropped): http://www.flickr.com/photos/calmenda/4500813971/sizes/l/
Elliptical chainring photo: http://www.flickr.com/photos/80253671@N04/12356829754/sizes/l/