Portrait Of Dr. Andrew Pruitt

Bike Fitting, Technology, Biomechanics and the Future with Dr. Andy Pruitt

BY TrainingPeaks CoachCast Host Dirk Friel

Explaining biomechanics on and off the bike, the balance of aero and power, plus the future of bike fits and bike safety.

Dr. Andy Pruitt, whose professional legacy includes the pioneering of 3-D bike fits, three patents for the development of Specialized Body Geometry shoes and saddles, all of which are designed to help optimize performance and comfort based on individual anatomy. 

Dr. Pruitt has spent his entire career helping thousands of riders from Tour de France contenders to local racers achieve their own brand of freedom and comfort on the bike. He served as director of sports medicine at the University Of Colorado and was a founder and director of the Boulder Center for Sports Medicine.

He joins Dirk Friel on CoachCast to talk about the origins of bike fitting, the importance of turning a foot into a proper lever for power, the balance of aerodynamic body position and power, the future of bike fitting and his next venture of making cycling safer.

Stand-Out Quotes

“Specialized had been working on some early ergonomically correct saddles and had great success. So they wanted to expand that thought process of ergonomic design products. [They] came to me and said, um, “If you were going to build a specific [cycling] shoe for 80% of the public, what would it be?” And I basically sold them some ideas.” 

“The foot is made for walking and running. It is not made for cycling, and it’s a totally different lever system in running and walking. The arch, for example, stores energy gives it back to you when you push off. So, in this pedaling motion, if it stores energy when we’re pushing down on the pedal, it’s not giving you any. It’s stealing that from you right at that moment. So you have to be able to mostly control the arch, control the forefoot and turn the cycling foot into a mostly rigid lever.”

“A footbed is simply something that’s going to help take your flexible arch that’s useful for walking and running and give it some support and some structure. So, they come in all kinds of designs of stiffnesses and arch heights…and I would encourage that [buying a set] be done with some professional help. Most of the good shops have a professionally trained fitter that can help you assess how much arch support or forefoot support you actually need.”

“You’re a four-day-a-week guy, and all of a sudden, you get this jones to go do Unbound, even a hundred-mile gravel race, and all of a sudden, you’re riding six days a week, and 12 hours a week. Fifteen hours a week, so you may not have had a problem at the four-day-a-week right. OK, but that same issue, same alignment, that same position is going to be more problematic at the higher level, right? I think there’s so much good advice out there as far as coaching advice and fit advice, shoe choice, foot prescription…but there’s so much good advice out there. There’s some charlatans; let’s not think there’s not. There are some charlatans out there. There’s some wannabes or make believers. But there’s so much good advice out there that if somebody listening is thinking about doing their first gravel race or their first Gran Fondo, please, get some professional advice about training and about your setup.”

“There’s no value to stretching for injury prevention; there’s no value to stretching for increased performance. Except if the increased performance comes from an aerodynamic basis, right? So if you start a systematic, progressive stretching program, you can see an increase in tendon length. You can see an increase in your range your mobility. It may take you six weeks to achieve that change—persistent daily stretching, and once you achieve it, you’re not out of the woods because it won’t stay. Right? As soon as you stop stretching. It’s gonna go back to its prescribed length, right? So for that aerodynamic athlete stretching is crucial. I’m 71-years-old, and I still love the time trial. I still love to ride my Shiv.”

“I think that we will have an automated bike fit with very little human component in the foreseeable future. I think the algorithms and the data collection is so deep now, OK. I think the computer could calculate saddle height saddle, saddle fore-aft, how many wedges you need in the forefoot, how much arch support you need based on…what the computer has seen so many other times. So I think that’s doable, and that’s going to take that seventeen-year-old at the bike shop out of the equation who’s trying to do your bike fit, right? So, there’s a certain level of athlete that that’s going to be just fine for.”

“I spent forty years saving lifestyles. And the end of my career is gonna be actually saving lives. It’s a company called Spoke Safety that has a technology that, when it becomes global and ubiquitous, will allow all cars to see cyclists. Let’s say vulnerable road users—that includes motorcycles, bicycles, scooters—and for those vulnerable road users to actually see the car.”


Dr. Pruitt on Fast Talk Labs

Specialized Body Geometry

Spoke Safety Technology

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Coachcast Host Dirk Friel
About TrainingPeaks CoachCast Host Dirk Friel

Dirk Friel is the host of the TrainingPeaks CoachCast and Co-Founder of TrainingPeaks. He is a lifelong athlete with a passion for cycling and ski mountaineering and firmly believes in goal setting, dedicated deliberate training and coaching for all. Learn more about his work at TrainingPeaks and follow his adventures on Instagram @dirkfriel.

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