Quality work Jamie. I personally think 4:45/km is a good target for London. That might seem a bit conservative but I’d rather you finish strongly that be hanging on for dear life, or worst still having to drop the pace considerably to get to the finish line. I think if you set off at 4:45 you’ve going to feel strong through the first 16-18 miles and then potentially even knock a few seconds off towards the end and come in under 3:20. That would be a big improvement on last years time. Obviously that’s weather dependant. Do I think you could go a bit quicker? Probably. But you want to enjoy it too, and a 6 min+ PB would be very impressive.