by paddlesteamer on 1/15/22, 8:38 PM with 106 comments
by trentnix on 1/15/22, 10:17 PM
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).
by savant_penguin on 1/15/22, 9:24 PM
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
by jonah on 1/16/22, 12:02 AM
A lot of headlamps do this for example. https://www.petzl.com/US/en/Sport/SPECIALIZED-headlamps/DUO-...
by csours on 1/15/22, 9:51 PM
by SergeAx on 1/16/22, 9:21 AM
> 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!
by hourislate on 1/15/22, 9:28 PM
>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.
by ghastmaster on 1/15/22, 9:19 PM
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.
by blensor on 1/16/22, 6:25 AM
That looks actually useful
by toddm on 1/15/22, 9:16 PM
by aghilmort on 1/15/22, 9:33 PM
by carbocation on 1/16/22, 10:32 AM
by virtuallynathan on 1/16/22, 1:50 AM
by ck2 on 1/16/22, 4:03 AM
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.