Tips on upping from Half Marathon to Full Marathon in 1 month

Pog

Hello - here's the deal. I'm doing my first Half Marathon training programme (Garmin Coach) - week 10 of 16. Going really well, ran 17.7 miles on Sunday (longest ever run) in around 02:50:00. Aiming for under 2 hours for 1/2. Programme finishes 12th June. I've just signed up for first ever competitive race (Chester Half Marathon 19th September). Plan: Start the programme again with a more challenging time when the programme ends, giving me just enough time to complete it before the race. Cool. NOW: Is it feasible to train between 19th September and a month later to compete in a full marathon? Any suggestions as to how I could go about it would be much appreciated. I realise it isn't long, but the long runs with Garmin 1/2 marathon will be knocking on the door of 20 miles anyway. Thanks so much for your interest in my post!!