If you watched any of the time trial stages for Tour de France last July you saw a wild variety of aero bar positions—perhaps the strangest being Floyd Landis’s arms-up, ski racer position where his hands were level with his chin. Other had their hands pointed slightly downward as if they were going to hit a volleyball. Still others shot their arms straight out ahead (pretty much Lance Armstrong’s style). You’ll see the same thing at any triathlon, arms and hands bent in all sorts of angles as people ride past.

All these different angles lead to the big question: Is there a perfect angle for your aero bars, one that will make you that much faster? The simple answer is that there is no ideal position for your arms in an aerodynamic tuck. Your number one goal is to reduce your total frontal area to as small a space as possible. That means you want your elbows close together and your back flat, and whatever arm angle allows you to hold your body in that position for the duration of a bike leg is best. Whether you’re bunched up like a ski racer or strung out like Superman, your top aerodynamic priority is to keep that frontal area tight.

Beyond that, the differences in positioning become nuanced arguments between theory and comfort. When looking at an arms-up position ala Floyd Landis’s “praying mantis,” you can theorize that he’s slicing through the air more efficiently since his arms could be directing more air away from his body. But it’ll take months and months of training to be able to hold that position throughout a one-hour effort. That’s because arms-up equals less support for your torso compared to a position where the forearms are horizontal. The torso has to work harder to support itself. But when the forearms are flat, you can rest your weight on the meaty part of the arm and let those arms do their part to keep you level.

If there is one angle that trumps all the rest it’s the angle between your upper arm and your torso. You want it dialed to 90 degrees as this provides the strongest and steadiest support between arms and upper body. If you’ve got the flexibility to ride with a flat back, then your upper arm should be perpendicular to your back and the ground. With this angle, you’ll delay muscle fatigue in your arms which has two benefits: The first is that you won’t tire out as quickly. The second is that the fresher your arms feel the better you’ll be able to control you bike if you have to make a split-second maneuver.

Of course all these tweaks and fiddles are meaningless if you’re not comfortable to begin with. Even if your bike was set up in a wind tunnel, its aerodynamic advantages are worthless if you don’t want to spend any time in the aero tuck. Comfort in the aero position takes time; time for your glutes and back to grow flexible enough to sustain that position and time for your arms and shoulders to grow strong enough to hold your body in place.

One trick I’ve picked up when it comes to adapting the body to aero bars is, assuming the rest of your bike fits well (cleats, saddle position, etc.), to make sure your forearms are comfortable, i.e. they don’t feel pinched, they hit the pads in a way that makes you feel like you could leave them there for the whole ride. Once you establish that position, no matter what it is, I’ve found that the rest takes care of itself.

CTS Coach Ryan Kohler specializes in coaching cyclists, triathletes, and adventure racers. For more news and information on the latest in nutrition and fitness, go to www.trainright.com/newsletter.