It's true that it's generally speaking it's older people and more overweight people who are much more at risk of developing severe symptoms, or even dying, through infection with Covid-19 than 'younger', 'fitter' and less overweight people. But it's now also clear that one major factor determining the severity of a SARS-Cov-2 infection is the size of the virus load you get in the course of being infected. If your respiratory tract gets a very big dose of the virus in one go, or is exposed to larger doses repeatedly, then the chances of getting really ill - even if you're young and (fairly) fit - is much higher. That's why significant numbers of (relatively) young, fit and slim healthcare workers working around patients with Covid-19 have been dying in various countries in recent months - because they were frequently exposed to people with Covid-19 infections, even while themselves wearing (some level of) protective gear.
I've done some rolling myself (although not in the last few years) and I can't think of any way you can really get closer, for longer, to another sweating, panting human being, while you're sweating and panting yourself. Apart from...
Although even during good sex you might (sometimes) not actually be exchanging as much sweat and respiratory droplets/aerosols as you will be during rolling!
(Feel free to differ on the basis of experience ...
)
Plus, in a normal gym session you'll probably be rolling with at least 3 or 4 other people, if not more.
Sure, you can then assume that the chance of a training partner being infected is far less than it is in a hospital ward, but IF someone else has the virus, even if they're totally asymptomatic, then the chance of catching a high viral load, with the said consequences, is more than vanishingly small.
This risk is, I would think, also a lot higher as compared to training tuishou / applications / sparring outdoors, where both partners can wear a more effective mask and disinfect hands and maybe face before and after, and wearing the mask probably won't give you heatstroke.
Some people will still roll and maybe/probably they'll be OK, but I'd say they are still running something of a risk, both for themselves and for others in their contact sphere.
Unfortunately. Really bitter for the people for whom this is their main type of training. I was actually planning to start doing some rolling again with a small and easygoing BJJ group here in Berlin later this year, but I guess that will go on the back burner for the time being.
You lose sir.
Glad to see some things never change.
Though, there is a notion/suggestion that a complete face shield is better than a mask.