Citation needed. Which is the point of the person you're responding to. For an untrained person to even get to what is considered 'high' intensity in their first workout is not common.
I do all sorts of training with trained and new people alike and have never seen rhabdo in person. I know it can happen, but I think the stories stick out because it's so uncommon.
But no citation needed from your personal experience of never seeing it..? I think you're reading waaaay too much into what I'm saying.
I know it happens because I've read articles of it happening. But the way people bring it up any time a fitness discussion occurs is a meme at this point.
Btw here is a local source. Three people got it from a group session. The doctor in the article says it happens about 400 times a year in little Norway, and that the group most often affected is people that used to be fit many years ago, and then start off too hard.
https://www.nrk.no/nordland/innlagt-pa-nordlandssykehuset-me...
- This wasn't one group session but repeated sessions of HIIT back to back (maybe even daily).
- There wasn't sufficient rest between sessions.
- Some of these were older (50+) patients.
The most important part is the repeated sessions. Doing a single session of HIIT pull-ups or sprint intervals on the bike aren't going to cause major muscle damage, even in an untrained person. Doing 5 days back-to-back, repeatedly going beyond failure (something Crossfit is notorious for), with improper form, are what causes the issue.
Most of what I read points out that it's more likely to happen to untrained individuals. It may be because they start to hard over multiple days, but that's not going against what I've said multiple times: that it's a high risk for untrained individuals jumping into high intensity training. _That's_ my point.
This statement erases all nuance in the real world data and experience of anyone involved in training.
You need to differentiate between one HIIT session and repeated HIIT sessions without recovery. The former doesn't cause injury in the vast majority of individuals. The latter is known to cause injuries in everyone trained or untrained.
You also need to control for what the HIIT session is. If it's spinning on a stationary bike for 2 minutes, an untrained individual generates nowhere near enough force to then injure themselves. If you're putting a set weight on a bar and asking them to shoulder press it, that's self-evidently completely different.
Yet, in your argument, they're exactly the same.
For the 3x20s intervals, the max effort of a person is far, far, below the max effort that, say, I can put out (as a trained cyclist). I strongly doubt the people doing this were actually pushing the 500W for 20s that I saw bandied in another thread. They're more likely pushing 200W and tickling 300W for a few seconds. This is still a high perceived exertion (though lower absolute kcal expenditure), so it's a good effort on their part. But they're unlikely to black out or cause major muscle injuries beyond feeling a bit sore in the morning.