That result made it two wins on the bounce but Adkins knows they face a difficult task against play-off chasing United at Bramall Lane.
"We've had a good conversation about how to prepare ourselves so we can make sure that come 12.15pm on Sunday we're ready for it and we're flying out the box full of energy," Adkins told the club's official website.
"We want to come out full of vigour and full of verve to try and win a game we believe we can do away from home against a side going for promotion to the Premier League.
"The momentum is with us now and we want to try and get going at this stage of the season. We know we can win away from home and we're going there with the belief we can perform like we did against Peterborough on Tuesday night."