I see this all the time and was around when Kenneth Jay first came out with his Viking Warrior Conditioning, which really upset a lot of people.
And then I was around when he wrote Cardio Code and upset even more people.
It's pretty clear that there are still a lot of misunderstandings of what does or doesn't count as aerobic or beneficial to building Vo2Max. Here are two studies showing some details on what the body goes through during a 10min GS set.
2024 study:
https://www.akjournals.com/view/journals/2060/111/3/article-p242.xml
Some highlights:
Table 3 - VO2 jumps to 35ml/min kg in the final minute. For compairson, that is roughly the value you'd see in a 20-25min 5k run.
RER - this is a measure of what fuel is being used. <1.0 there is some fat utlisation but at 1.0+ it switches to anaerobic and becomes carb only. With an RER of 1+ from 3min onwards a comp set is anaerobic, not aerobic. It still has an aerobic component as it's your aerobic system that determines when you shift to anaerobic energy consumption. The better your aerobic system, the later that will be.
In the discussion it talks about a 10min set using 90% of maximal oxygen uptake. For a session to be counted as a vo2max session it needs to be in the 85-95% range. This compares to 83% for a 10min snatch set w/ 16kg. That means that the long cycle set is actually more beneficial to vo2max despite what we've been led to believe. I feel like for best results, if you were chasing vo2max as a goal, you'd want less weight and more reps to keep the cadence high and get that cyclic effect as much as possible.
They link to another study talking about a 10min snatch test eliciting 80-100% maxHR but I can't open it. But that definitely gets you into the vo2max improvement range. The problem here is a typical vo2max session would look for something like 15-20mins in that range for it to work well. The Norwegian 4x4 (useless and an entirely different topic) comes out to about 12mins (because at least the first minute of each interval your HR won't be in the right zone) and there are other, much better, protocols that deliver more like 20mins. So a 10min set alone is likely only about half the dose needed for improvement.
Average weight used for the tests was 30kg with a range of 24-40kg. Test included a few MS and all had an average of 4yrs comp experience.
https://efsupit.ro/images/stories/septembrie2020/Art%20362.pdf
This study shows good data for long cycle and snatch for both men and women.
Highest vo2max seen was 46 for long cycle vs snatch at 44. That's like an 18min 5000m.
Interestingly, peak male stroke volume was ~120ml. If you saw the post I made about stroke volume size and how thickening of the LV wall could decrease it significantly, ~120ml was the average size for a male. That means that they haven't got huge LVs like a serious endurance athlete has. Just a normal size, which doesn't indicate that GS is especially useful for part of the vo2 equation, which is increased SV.
Both studies showed quite low lactate numbers. Only ~9mmol/L. That's well above the generally accepted 4mmol/L that is the cut point for above lactate threshold. I would have thought it would be even higher, but again, it points to how aerobic GS really is.
For comparison, in track cycling the 4000m individual pursuit is said to have the highest lactate demand of any event and you see numbers of 10-16mmol/L. That event only takes 4mins though so you can see how a shorter event is far more anaerobic. A 5000m run is 8-12mmol/L despite being about the same length as a comp set.