Trakhak

An anecdote I'm prone to dropping whenever the "but weight on the wheel!" discussions arise:

Back in my time-trialing days, I bought a pair of absurdly light and fragile Hi-E wheels, when they were probably the lightest wheels on the market. I used them for a few rides and then sold them, solely because I disliked that I could feel the lack of a flywheel effect. Riding on them felt like a series of pulsing micro-accelerations.

Writing that now, I suspect that my memory of the way the wheels rode might have become a bit overblown over the years. Still, I did sell them, and I rarely sell anything, as my cluttered basement demonstrates.

In any event, I went back to my reassuringly steady-state Campy/Mavic GP4 wheels.

MoAlpha

The GP4s were fantastic for that era and that dark gray was badass.

Carbonfiberboy 

How do you figure the bolded part? Like if I rapidly diddled my car's accelerator but that didn't change the car's speed, that would not affect fuel consumption? I don't think so. I think that's a valid comparison, though I expect we will disagree on that point. Can you show me the physics of that? Micro accelerations are still accelerations even if they don't affect the numbers on our devices. I know, the effect is very small, but it's there and small things add up over the hours. Randonneurs complain about beginning to "pedal squares" when very tired. It can be hard to maintain one's efficient pedal stroke. It helps a lot if one has trained those ganglia. That's never happened to me, which might help to explain the good results of a weak cyclist like me.

RChung

I try to instill in the students that we should never let the lack of information restrict the breadth of our opinions but always let it limit the strength with which we defend them.

terrymorse 

Yes, it is physics. More specifically, thermodynamics.

Humans and cars are both thermodynamic engines, but they are quite different.

Accelerating a car is energy inefficient because acceleration a heavy car requires substantial power, and internal combustion engines are not very efficient at higher power levels.

Human engines don't suffer quite the same inefficiency problem at higher power output, so accelerating on a bike is (more) efficient.

PeteHski

You are right, I don’t think it is a valid analogy. If the car speed isn’t changing, then oscillating the throttle is likely just dumping more unburnt fuel. It has nothing to do with conservation of KE when pedalling a bicycle.

Pedalling “squares” vs pedalling “circles” can mean whatever you want it to mean, but again has no relevance to the physics here.

MoAlpha

That’s a good formulation. The problem for the general public and a distressingly large number of professionals is the inability to distinguish between reliable data, unreliable data, and sheer opinion. Sounds like your students have mastered that part.

RChung

I work in a field where we don't usually get to do experiments. We work with crappy observational data so have evolved a lot of methods and techniques to assess and work with crap data. That's why the statistical techniques used in non-experimental fields are so much more sophisticated than the stat used in experimental fields. In physics or chem or engineering, when they get crappy data they just re-run the experiment. We don't have that luxury. (As an aside, my approach to measuring bike drag uses data that everyone else thought were too crappy to use. I just used the methods we use for crap data and because the data from speedometers and power meters and barometers is so much cleaner than the stuff I'm used to working with, the results turned out pretty well).

Another thing I tell the students is that there are those whose confidence in their opinions varies not with how much they know, but with how much they think you know. Basically, I tell them not be mansplainers.

Carbonfiberboy 

I don't know if that's true or not. I've never seen a rec for 1RM training per se. Many people check their 1RM and use a percentage. I don't even do that. I just go to exhaustion and choose my next week's weight on that basis. Why would I need to know my 1RM? Silly, IMO. Risk of injury. OTOH, I don't know anyone who does what I do. Maybe they're out there? Hard to know. So far, everyone I know who's tried it said "I can't do that." My oddity is that no, I couldn't do it either, but I kept trying. I remember when I started serious rock climbing. I spent a month just getting off the ground on a new pitch. Nothing wrong with that, other than perhaps being a little obsessive. OTOH, my FastPedal routine was recommended to me by Ed Burke. I suspect he's out of fashion now. My one-legged pedaling routines were sent to me by Pete Penseyres many years ago. I knew he had done that and asked for his recommendation.

MoAlpha

Economics? Grad students or undergrads?

Yes, the worse the data, the better the stats.

In the better neighborhoods of the clinical and human subjects world, we don’t let people rerun experiments unless they put that in the protocol and it’s approved before they start and then we may make them halve their alpha. Animal research is still the Wild West.

The Dunning-Kruger effect is always with us.

Carbonfiberboy 

No, I don't have any data because no power pedals. I'm not going to spend $1000 on something that won't improve my cycling just to post stuff. My only data are my finish times and placings, which in my view are what matters. Everything else is evidently arguable.

RChung

Thank goodness, no. (Although I studied Econ and have a grad degree in it). I just retired ("just" as in, Dec. 31) from one of the few PhD-granting Demography departments in the world.

Yeah, I split my time between UC Berkeley and UCSF, but I've never done RCTs. I worked with observational data, mostly administrative but some clinical, typically with tens of thousands or tens of millions of cases, to assess quality of care. Demographers know a lot about large datasets, how to look for data anomalies, and how to standardize to level the playing field. I've been yelled at by some pretty (in)famous physicians.

MoAlpha

Your observations are fine data as far as I’m concerned. I was referring to data from well designed experiments we could use to answer the question of what is likely to help most people.

MoAlpha

Sounds interesting and valuable! I need to retire too.

Have you been yelled at by Ioannidis? I feel as though he has been yelling at me for the last 20 years even though I’ve never met him!

I am actually a cognitive neuroscience guy with a background in neurophysiology, but I have been involved in many trials over the years and I chair the scientific review committee at my NIH institute, where we clean up human subjects protocols before they go the IRB. I have gotten pretty savvy and hardass about design and analysis, at least for a doc.

RChung

Nope, but I won't say who I've been yelled at, other than to say that my work has shown that *when adjusted for patient status at time of delivery of service*, the quality of care at some big Academic University Medical Centers is smack dab in the middle of the distribution, i.e., I was being yelled at by big important guys who think they're hot stuff and I was showing that *when adjusted for patient status* they were getting outcomes that were expected. I never got yelled at (to my face) by guys who were at the bottom of the distribution, I was getting yelled at by guys who thought they were god's gift and I wasn't showing that.

That's a tough job.

Carbonfiberboy 

At least there's another person somewhere . . .
https://ispyphysiology.com/2023/07/1...nstead-of-two/

I finally had a successful FastPedal this evening. I haven't been warming up enough. Gotta do more to open up those arteries before I do anything interesting, lots more than only two years ago. Must be age. It's "interesting" that there's so little knowledge about coping as an aging athlete. Anyone? My current plan is to do a lot of FastPedal until I can spin the pedals fast with a lot less HR, Z2 training with an easily seen marker. I've been good about going to the gym, so decent muscle but not anything like enough cardio. I'll go back to doing the LSCT warmup: https://www.highnorth.co.uk/articles...l-cycling-test
I didn't think I needed that for doing a FastPedal, but I think now I have to.

Also found another crazy person: https://ispyphysiology.com/2023/07/1...nstead-of-two/