United will be expected to struggle next season, but Adkins is maintaining his positive outlook and reckons the stay in the Championship will be for longer than one season.
"It is a massive step up, but Colchester have done it - they have proved it can be done," he said.
"It's like Roger Bannister breaking the four-minute mile, no-one thoguht it was possible and he did it. Then suddenly loads of people were doing it.
"It is possible, we are capable of doing it and we have got to believe it is possible."