I'm a big fan of `starting out slow.` Jumping into a 7 day retreat is not starting out slow.
It's different for everyone what `slow` is, but if you're not sure if you're ready for a 7 day retreat and you go anyway you might end up like this guy (in the article).
What do you reckon is the ideal way for a beginner to get into meditation, then? Particularly if that beginner lives in a busy, noisy place like London and has a busy, time-consuming jobs like running a start-up.
Ideally, you would find a regular meditation group that has one or two weekly sessions of maybe 30 minutes and some members with experience who can give you hints. That gives you a commitment to regular practice and a supportive group of peers without being too invasive. Skipping a week isn't a big deal, either.
Having tried it both ways, I think beginning with thirty minutes a day or something like that is like trying to learn to swim in a bathtub.
Unless you're on the edge of psychosis, a long retreat won't hurt you. There are rare horror stories about somebody going nuts, but that's probably about as common as somebody dying from a bee sting.
I don't see why I'm getting down voted. I've been meditating on and off for years and I wouldn't just jump into a 7 day retreat until I was ready, it's do-able but probably not pleasant.