Portable replacement for a $60k VO2 Max machine (opens in new tab)

(instructables.com)

229 pointspaddlesteamer4y ago106 comments

106 comments

This is really great. For those who aren't familiar with what these machines can do, the calculation of an athlete's Vo2 max really isn't all that useful. However, a breakdown of the fat and carbohydrate calories burned at various efforts can be incredibly useful for helping an athlete learn how to fuel correctly for performance over distance.

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).

dpeck4y ago

I appreciate the modesty, but talking about completing an Ironman and having the phrase “really wasn't all that fit” anywhere near it is comical.

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.

andreskytt4y ago

Not necessarily true, I think. It’s a mental barrier more, than a physical one. Tell someone you ran 100 m in 12 seconds and they go “meh”. Tell them you did a marathon and they go “i could not do that, awesome, how could you etc.” whereas an average person can do a marathon with a years worth of training and never achieve that sprint time.

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.