Portable replacement for a $60k VO2 Max machine(instructables.com) |
Portable replacement for a $60k VO2 Max machine(instructables.com) |
I'm not a physiologist or physician (and I'm sure what I'm about to say may be max cringe to the bonafide experts that are around), but my basic understanding is that when expending effort, you burn calories from fat stores and from glycogen stores. Glycogen stores store around 2000 calories, and expending one's glycogen stores results in hitting "the wall" - your body simply doesn't have any fuel to proceed. Your fat stores, on the other hand, provide access to tens of thousands of calories.
People are generally fat-inefficient - any effort immediately biases towards consumption of glycogen. And when you're out, that's it. Your day is done. So knowing the rate you're burning carbohydrate calories can inform an athlete how often and how much to fuel.
Some people are born "fat-efficient", meaning they can access their fat stores easier. Fat efficiency can also be improved through low-intensity endurance training with improved diet. So athletes will periodically do a VO2 test to stay in-tune with how their body is using the fuel sources available to it.
Many years ago I did an Ironman (Couer d'Alene) and a Vo2 test indicated I needed to aggressively consume calories (at the effort I was planning to ride) on the bike. After all, you have to get off the bike nutritionally prepared and hydrated to run a marathon. So that's what I did, and I had a good day considering I really wasn't all that fit.
Endurance and ultradistance events aren't really tests of toughness. They are science experiments. It's all about figuring out how to take one's fitness and stretch it over the distance of the event.
One additional note - there are machines much less expensive than 60k available, but they are still pretty expensive (in the thousands).
Getting through any one of the stages of an Ironman (or heck even a half of each stage) represents a level of fitness most adults do not have and will never attain.
It took for me 21 months of training to go from effectively zero to a half ironman and the biggest barrier was swimming, which is very technical in nature. I still can’t swim very well. I was in no shape at all and overweight. If you look at the speeds required to stay within ironman time limits, they are quite low and a person in a slightly better than average condition would be able to sustain them with relative ease. The barriers might be swimming technique (which one might have from training as a kid) and things like biking position and running technique but not necessarily fitness as such. In fact, I see quite a few people visually in much worse shape than I am (i.e. fatter) doing long IMs and beating me at shorter distances.
Also there are perfectly ordinary ways to figure out you need to eat more, Ive coached some pro cyclists and done a decent amount of my own triathlon and cycling adventures and if someone gave me a free vo2 machine I don’t think I would ever use it.
in the 10 days before the race I would predominantly eat a high fat diet. Based on all the testing I’ve done, what you eat in this window has a large impact on how your body uses fat vs carb on race day
I can hear thousands of Garmin owners screaming about this comment as they obsess over their VO2 Max.
[1] https://www.sciencedirect.com/science/article/pii/S002604951...
[2] https://web.archive.org/web/20201111190720/https://zachbitte...
naively, it seems measuring oxygen consumption would be useful.
Also unlike aerobic fitness, which can be improved with year after year of consistent training, an athletes peak Vo2 max (for their given fitness) can be maxed out over 4 - 6 weeks of specific training. Doing much more specific Vo2 training can result the athlete (at least in running) becoming ‘flat’.
That said Vo2 measurement can provide a great deal of useful information but for most recreational athletes getting the basics right is more important than having an exact Vo2 measurement.
That said, it does provide some correlation to an athletes performance “ceiling”, and you’ll typically find elite endurance athletes are naturally blessed with an impressive Vo2 max. You’re not going to win the Tour de France with a Vo2 max of 50 no matter how hard you train, just like you’ll never play Center in the NBA if you’re 6’1.
Sure I won't have the minutes detail of million dollar medical equipment, but maybe I don't need all that precision, or maybe that's better than having no access at all to the measurements at all
Source: I know people.
A lot of headlamps do this for example. https://www.petzl.com/US/en/Sport/SPECIALIZED-headlamps/DUO-...
> I have found that with the calculations for energy expended from the Oxygen utilization algorithm is slightly higher than that calculated by the work/watt output of the Zwift App algorithm.
I beleive this is because Zwift doesn't count a basal metabolic rate. As far as I understand this is a default behavior for all calorie tables and trackers, one must calculate and add that constant manually. This device can actually measure that value!
>My wife is an Ironman as well (Muskoka, Tremblant and Penticton). . She's been using Zwift since last year. Great way to train btw and great idea but. My concern would be a collapsed lung(s) if this wasn't calibrated correctly. To each their own, but stressing your lungs and diaphragm this much isn't a great idea.
In a lab they can at least make sure you don't hurt yourself.
You can pull a pretty good vacuum with just your lungs, so I'm not overly worried about that. And pressure is not a problem unless you have a weak spot in your lung.
But still, it's a good point to make and maybe the author could measure the flow resistance in both directions and optimize for that to ensure that it never becomes a problem, even in people that might have a hidden defect.
Especially considering the following:
> Physiology labs that are normally used for testing VO2 max cost upwards of $60,000 and are certainly not portable. They have sensors that measure the same things only on a much finer level.
The person who posted the article here must've had HN's audience in mind, so they chose a different title.
Titles convey ultra-dense summary of the content, so there can be many titles appropriate for any given article. The purpose of the title is to attract _attention_ of the audience who the title-writer thinks would find it most interesting.
The reason someone writes an article, or posts in a forum, is to spread an idea, or a message, and have other like-minded people, or people who may find the info useful, read it. Exception: content written for commercial/monetary gains has no goal other than grabbing eyeballs, to make more money.
So, yes, it's okay to edit titles, but only if they're egregiously misleading, or inappropriate, or if there's a better title to convey the summary and attract the attention of folks in the said forum.
Context (as to why this request of yours triggered me): https://news.ycombinator.com/item?id=25093563
Regarding your post, I am curious if "Google" was removed by yourself(and later changed your mind) or the moderators?
That looks actually useful
Some serious next-level hardware hackers this generation.
I get worried everyone is turning into dumb iphone+app users but this advanced creation stuff restores faith.
uses a $20 BME680 on a $10 PI, I am really tempted to try it since the standalone sensor for my weather station is like $150
If $DISEASE kills 10k people/year, and $DEVICE can save 90% of them but 5% suffer $DEVICE related deaths, delaying the release 10 years trying to get to 0% related deaths doesn’t sound like the best strategy.
But I doubt it is enough to draw a vacuum strong enough to break adhesion. Still, better safe than sorry, it would be good to read the instruction manual of a professional unit to see what kind of failure modes they have listed there.
Just as the ability to learn how to fly planes within a year doesn't change the fact that most people aren't and won't become pilots.
The fat burning starts when you empty the glycogen chambers, but there is a sweet spot in terms of energy output, because as other people has pointed out, you can't do high intensity work on fat.
So it makes sense as an ultra endurance athlete that you try to pack som fat before a race, because it will be effective as a slow burning resource.
Another interesting thing at the moment are the ketones supplements one can drink.
> Several compromises were made in the design of the unit: no CO2 sensor
[1] https://news.ycombinator.com/item?id=25093563 To summarize the contextual thread, the title of a post was de-clickbaited against the OP's intentions. In my opinion, for the better.
Never Use Google to Sign-In
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If $DISEASE kills 10k people/year, the company manufacturing the device doesn't have to pay anything for them.
If $DEVICE kills one child, the company manufacturing the device is on the hook for several million dollars.
So your $DEVICE needs to clear (roughly) 10K*5%*$2 million per person killed or roughly $1 billion in profit to be economically feasible.
That means that those 10k people need to spend, $100K+ each for that device to make it feasible.
It's not just the FDA that makes companies want to drive that 5% down to damn near zero.
Standard CPAP machines max out at just over 0.25psi, and even ventilators usually max out about 0.4-0.5psi.
If you're interested in some of the other physiological impacts of keto adaptation, here's a presentation Volek gave a couple years ago that helps contextualize both the FASTER trial and a related TANK trial his team ran, as well as some other interesting related performance research: https://www.youtube.com/watch?v=BeS_dhM8dsY
[1] https://www.sciencedirect.com/science/article/pii/S002604951...
[2] https://www.sciencedirect.com/science/article/pii/S002604951...
[3] https://www.frontiersin.org/articles/10.3389/fphys.2018.0059...
That being said I will haven't learned how to use it in a meaningful way myself. Getting a good image, and then interpreting the 2d video stream requires training!
Making ultrasound easy enough for non specialists to use will require an AI that guides the user and interprets the images. I'm not convinced skipping FDA approval would be a good idea in this case.
If you actually need to measure something, analysing the 2D images is much more precise.
EDIT: Also, it's really hard to visualise density in a 3D view.
https://www.fda.gov/news-events/press-announcements/fda-issu...
I think my marathon was a 5:30 or something like that. Lots of walking, but I never stopped moving.
As for "hitting the wall", this often happens around 20 miles as this is where your stored glycogen is depleted. To avoid this happening, you'd be better off to "train the gut" to handle consuming ~60g carbs per hour while running at your target pace/intensity.
Also,noone is stopping you from making a DIY ultrasound and selling it to enthusiasts.
You’d be surprised at how much is just about filling the proper paperwork, paying some fees and knowing the right people. The amount of independent testing is negligible.
You may be referring to the 510k (pre-existing predicate device) pathway, which has been abused by companies to leapfrog and skip _some_ of the more stringent test requirements, but they still need to prove similarities, and that requires real data. However, in the vast majority of cases, these devices are things like masks, IV tubing sets, etc, not complex life saving equipment, which gets an enormous amount of scrutiny. If anything, it's the medical device companies that are at fault for lobbying Congress to allow abuse of 510k pathways, and Congress for allowing these things to happen.
Paperwork, they require paperwork.
It’s the same issues that plague FCC and CE, the amount of tricks and handwaving you can get approval for makes a lot of this (self performed/self directed) testing completely useless.
There’s a whole market of “expert consultants” whose job is gaming the tests and finding loopholes, and as long as tests are conducted in this manner, they will exist.
This is a government at the end of the day. It would be imprudent to not consider the effects of regulatory capture, cronyism, and so forth.
I have some experience, and i can think of about a half dozen ways cpap machines and hearing aids could cause serious harm as a result of design flaws or lack of QA that would be de rigeur if not for regulatory pressure.
Most of the ways I can think of a CPAP failing would be extremely obvious with equally obvious and relatively low-impact effects (I get a crappy night's sleep or wake up in the middle of the night).
https://www.fda.gov/medical-devices/safety-communications/ce...
Incorrect use of CPAP can lead to development of central apnea. (Even APAP machines can be programmed to keep the pressure too high which is long term unhealthy).
With that, I am all for liberalization of the laws. My GP did not prescribe me a CPAP machine despite obvious signs of apnea. "Lose some weight instead" (that despite me having apnea even when I had a BMI of 21).
I never felt as much of a positive difference on my life as when I started using the machine and had my first good night of sleep in decades.
I wish my govt would let me buy an insulin measurement device, but nope, those too are regulated and not available for the general public.
Do we?
I was under the impression that there has been an uptick in hearing damage in young people due to them increasing the earbud volume above background noise levels (not so much of a problem in earphones that cover the ears as they block out outside noise).
That's a medical problem that will have significant effects downstream over time and the consumer regulation really isn't working.
Like I said, the world of predicate devices is a different ball game, but you're not going to get by with hand waving on a device that can kill people.
That’s not a good measure for the performance of the regulation. In fact I’d like to see the numbers on the exact reasons for those shut downs, because I’m willing to bet they’re related to bad classification and other technicalities.
If the FDA were to be a test, you’d want it to have good discrimination at a low cost.
Anyone who has been involved in the process knows the cost is enormous, and scandals like Theranos (and good but extremely late good cases) show that discrimination is not that good to begin with.
These regulations are written in blood. They're difficult to comply with because if you invite poor engineering you will get poor engineering and dangerous devices.