Insights into Bike Myths and Truths (part 2) Posted on June 10, 2017, 0 Comments
This is a continuation of an earlier blog post, the first part of which can be found here:
These are some really good examples of how individuals thoroughly (and properly) trained in how the body works, can take that information and thoroughly complicate the simple act of pedaling a bike.
RESPONSE: As a cyclist pedals, the majority of force production is provided by the quadriceps, which extend the knee approximately 74° from 111° flexion to 37°. During extension, the knee also adducts due to the normal valgus angulation of the distal femoral condyles in relation to the foot/pedal interface during the downstroke. This causes medial translation of the knee as it extends. In addition, pronation of the foot coupled with internal tibial rotation increases stress on the medial knee. We have not even considered the roles of the vestibular components or how the various organ systems of the body are impacted as well as impact the act of pedaling a bike. Simple--I think that's not the most accurate descriptor.
"Just starting at #1, that's a great theory and probably true, except it never happens. Pedaling a bike with a crank arm 2.5-10mm shorter is so entirely similar to pedaling at the longer crank length that phrases such as " will likely cause a decrease in performance (e.g. power) in the short term until the body has acquired the ability to perform the new skill(s) autonomously." simply does not apply after the first 30 seconds. Body knowledge says it should, while thousands of real world examples say otherwise. Crank length change is below the threshold of mattering for anything beyond the positive change to thigh-torso clearance."
RESPONSE: An organism, when stressed, often reverts what it knows. It's why habits (even bad ones) can be hard to break. Survival is the driver here. The subconscious believes the reason you've alive despite all the challenges to that survival are because of the actions you've taken in the past--even if those actions haven't served you. Thus, it's very difficult to learn a new skill when the organism is under stress. It's also extremely difficult to practice a newly acquired skill when the system is continually stressed. Exercise is a stress. So even if you have a certain form that is more efficient/powerful, as you become increasingly fatigued the ability to use the new form/position/equipment decreases as the body goes back to what has gotten it this far in the first place. Thus, I don't doubt that after 30s a cyclist you've fitted on shorter crank arms sees some benefit. But at 30s, that's roughly 45 revolutions per leg. What type of impact do you think that has on the neural pathways of a cyclist who's pedaled 10hrs/week in a certain position with certain equipment for a decade? That's 520hrs in a year which equates to 31,200 minutes. In 10 yrs, that's 312,000 minutes. At approximately 90 "reps" per leg, that cyclist has a different motor ingram that has been ingrained in his neuromuscular system some 28,080,000 times. EACH LEG! My bet, is the cyclist might have some "issues" maintaining the same level of performance he achieved during the 30s of your test.
The funny thing is, I was actually agreeing with you on this point, simply saying there will be an initial and temporary drop off in performance even if the change is, ultimately, going to result in an improvement. Of course, there comes a point when an improvement will not occur if the cyclist has found the length which works best for his/her physiology/chosen race. So I encourage a more cautious approach when using absolutes like "never" and the like. It demonstrates a keen inability to engage in anything other than linear thinking when a complexity model would likely serve you better.
For 2,3 & 4, I can't argue with Andrew, but I don't need to. There are multiple studies on changing cadence and modifying your force application beyond simple alternating pushes. The vast majority show a decrease in efficiency. How to pedal a bike in a steady state, time trial effort is pretty settled science. Track riders, sprinters, super high power instances and low traction situations are exceptions, that rarely apply to my target audience. The exception is not the rule.
RESPONSE: I was pretty sure your target audience was mostly multisport athletes. But because the initial observations were so general, I had to point out that--like anything--it depends. And again, I would be careful with info obtained simply from studies. Learning to interpret studies and their inherent limitations if not outright falsifications at times is an excellent skill to have. Just don't try to acquire it if your system is currently being stressed. However, if you'd like, here's some research you may find enlightening:
"As these cyclists have to engage in single-legged cycling, they have to generate force on the pedal with just one limb throughout the whole pedal cycle. This is going to result in a lower peak power (Bundle et al., 2006), as well as an increased time to peak power through a combination of the use of one limb (Bundle et al., 2006) and being seated as opposed to standing (Bertucci et al., 2005; Padulo et al., 2014). The exercising muscle mass is required to generate more force throughout the pedal cycle in one-legged compared to two-legged cycling resulting in a higher mechanical and metabolic load (Abbiss et al., 2011). However, the differential VO2uptake to one- vs. two-legged exercise suggests that there may be a circulatory inhibitory response to two vs. one-legged exercise (Ogita et al., 2000), and one-legged sprint cycling relying less on anaerobic metabolism than two-legged cycling (Bundle et al., 2006), this may contribute to different fatigue profiles in the C2 class. Additionally, single-legged cycle training can result in significant improvements in the oxidative and metabolic potential of skeletal muscle in trained cyclists (Abbiss et al., 2011)."
5. I addressed this, but to restate, I never suggested that riding a trainer or always using a super controlled environment was the way. What I said was ALL of those other skills and adaptations are relatively quickly and easily addressed, when compared to the scope and magnitude of aerobic development that can be better achieved in those super controlled environments.
RESPONSE: God, we agree on too much. The trainer is an excellent and, in general, the most efficient way to develop the aerobic system (with the added bonus of catching up on video coverage of races you may have missed). Indeed, when used correctly, I estimate that 1hr inside = 1.5hrs outside. So it's great for the working, time-crunched athlete. And for triathletes, whose race demands are not the same as road/mtb/track cyclists it may even be ideal. However, I would argue that anyone who claims skills such as riding in a tightly bunched group (which you've never experienced unless you've raced professionally abroad or in any of the World Tour races which take place on US soil) and descending at speed or cornering in adverse conditions can be easily addressed has never, in fact, actually done so. If you'd like to follow me down a rainy mountain pass in Spain sometime, I'd be happy to have you on my wheel.
6. Specific adaptations to imposed demands indeed. The primary demands of climbing a hill are light weight and high power. The secondary ones are gearing, pacing, "mental fortitude", and actually climbing a few hills to know how it feels and engage slightly different muscles slightly differently a small portion of the time. The only argument I make is (again) let's stop turning secondary demands into primary ones. The exception is not the rule.
RESPONSE: I think we're moving in circles here (but...that's better than squares to continue the cycling analogy). I assume most people coming to be fit by you have a bike. A secondary demand would be a good fit. I bet the reason these folks choose you is the secondary demand is appealing enough so they'll pay to have the benefit of your expertise. Put two cyclists with the exact same attributes/experience on bikes--one fit by you and one fit by Walmart--my money is on your guy. My money is also on the guy who has spent some time addressing these "secondary" demands I mention above.
7&8 Yay! We agree!
RESPONSE: Excellent as I'm starting to develop calluses from typing.
9. I think we agree here as well, but just to be sure.... Adaptation to climatic conditions is fast. Aerobic development is slow. The exception is not the rule.
RESPONSE: See my comment in #6 above.
10. "Flexibility/stability need to be developed before strength which needs to be developed before power." Again, I can't argue with this, but I don't have to. Flexibility is rarely a limiter in developing a world class bike position. It just isn't. In other words, it is not that hard to ride a bike in the same position as the best in the world. Most of us have the chassis to do so, but we lack the engine to go as fast. A tri bike is the most athletically demanding of all bikes, and even there, most riders can get national caliber results with the biggest limited not being flexibility / mobility / stability / strength / power, but far more often the 20 extra lbs hanging around their mid section.
RESPONSE: With all due respect, most folks chassis are out of alignment; quite often, severely so. In fact, I've never assessed a client--from stay-at-home moms to professional football players--that didn't have multiple dysfunctions which needed to be addressed. In regards to your target audience, I'll quote my book: "Flexibility is the ability to adapt to changes in position or alignment, allowing us to perform joint actions through a wide range of motion. Often used interchangeably with mobility, which can be defined as the ability to move freely, these two concepts are the heart of this chapter. They’re also the heart of the biomotor abilities above. Think about it—how agile can you be if your muscles are stiff? Have you ever cramped during a triathlon? Your ability to move or change direction quickly was instantly curtailed. In fact, if you weren’t stopped dead in your tracks, you probably looked like the Tin Man trying to jog a couple of days after hanging out in the rain all night. Being too tight also affects your balance. Pulled out of ideal alignment by tonic musculature, you are literally over-committed in one direction. Coordination will suffer, too, as a lack of mobility must be compensated for elsewhere in the kinetic chain, often resulting in inefficiency and injury. With altered length/tension relationships, the triathlete must now work harder to perform a given movement which adversely affects endurance. Muscles positioned outside of their optimal strength curve will not only be weaker but, since strength is a component of power, a final injustice to the inflexible triathlete is that these last two biomotor abilities will never reach their full potential—much like this triathlete and his placement in the overall field."
The phase "going lower isn't always faster" is without a doubt true. Here is a phrase that is 'more' true. "Going lower is usually faster." The exception is not the rule, and we need to consider the target audience.
Age group triathletes hear that 1st statement and sabotage themselves as they come into a bike fit determined to not ride "too low". Of course, simply bending them over to the will of the bike fitter is not the process. Taking them down, forward and adjusting crank length to achieve the lowest position where pedaling mechanics, breathing and digestion can be maintained is the goal. Anything higher than that is less aero the vast majority of the time. That is what the wind tunnel says, and barring a trip to t he wind tunnel, our best approach during a bike fit is to play the odds.
RESPONSE: Agree again--play the odds. But if we're just using odds without thinking, then I can have a monkey fit me with the same chances of any improvement. And, again, the funny thing is, I was actually agreeing with your original point.
The blog post is continued (yes, again) in Part 3.