If you happened to be kicking around Namche how quickly could you get from there to Island Peak summit and back? I'm not talking about some Kilian Jornetesque record attempt but the minimum number of days required for a fit person to do it, acclimatization issues aside.
It took us 2 days to walk from the base of Island Peak back to Lukla so 1.5 days from Namche to Island peak. We were travelling light and were fit and acclimatised, walking not running.
What do you mean by "acclimatisation issues aside"? You could do it in 5 days, assuming you've acclimatised to higher than Namche. E.g. Namche - Pangboche - Chukkung - BC - Summit and return to Chukkung - Namche. But if you've just been hanging out in Namche, you'd want more time.
Cheers Tom, by that I mean assuming someone (ok its me I'm talking about) were acclimatized. If it all seems a bit vague it's because I'm going to a wedding celebration in Namche and I've been asked if I fancy doing it and I'm just wondering how realistic it is, I'd no idea (until) Guy's reply how many days walk away it was nor how many days are required to climb. It sounds as though if I find myself with a 5 day window it might be possible to fit it in.
In that case 7 days is more realistic with acclimatisation/rest days in either Dingboche or Chukkung, and at BC. That would still be pushing it - you'd be better off doing something like Chukkung Ri if you're tight on time.
At best you'll feel awful on Island Peak on that schedule and at worst you won't feel terrible because you'll be in a coma etc. You definitely need some acclimatisation time thrown in.
Anyways, if one was really acclimatised to at least 5,000 m, then if you left Namche before sunrise, it wouldn't be unreasonable to hit Chukkung by the end of a long day.
but would you then be in a fit state to climb a mtn? I think given 5 days you would be better off doing a nice lightweight fast trek. Much more enjoyable.
Last time I climbed it, with a fairly strong group, we left base camp in the wee hours of the morning, summited around 10-11 am and then got back to Dingboche just after dark after packing up etc.