Posted: Yesterday at 15:34
Plus 11 min miles is almost 5 hours ? I really don't think its that crowded - unless you are in a wiiiide costume.
I always nip through gaps - they will open up in front of you - sure you might get a bit of congestion at the start - but starting steady usually pays dividends.
If you're bang on to scrape under 4 hour shape - then maybe London isn't the best to PB at - but you shouldn't lose 50 minutes.
One thing you shouldnt do is sprint to get past people. That wasted energy will bite you back.