Root was named was named as the successor to Alastair Cook as long ago as February, but Thursday's series opener against South Africa at Lord's will be the Yorkshireman's first match as England Test captain.
Test captaincy appears to have boosted the performances of such leading current batsmen as India's Virat Kohli, Australia's Steve Smith and New Zealand's Kane Williamson, with Broad confident it will inspire Root to greater heights rather be too heavy a burden for the 26-year-old.
"Joe's not had a huge amount of captaincy experience because he played for England from a young age but he's learned the game at the top level," Broad told Sky Sports News at Lord's on Tuesday.
"I think it will take his game to the next level, if he can go any higher. He'll really thrive off the extra responsibility.
"He's an attacking cricketer, quite aggressive in the way he plays, so I think the team will take that sort of shape," added Broad. "He was announced a long time ago and now he has the chance to put things into place."
Meanwhile Broad, a veteran of 102 Tests, insisted he was fully fit for the first of a four-match series against South Africa after his participation was called into question by a foor injury.
However, he played in Nottinghamshire's One-Day Cup final win over Surrey at Lord's last Saturday, bowling none overs with no adverse reaction.
"I got through the Lord's final with no problems and bowled Wednesday and Friday before that with no pain," said Broad.
"I pulled up really well and I'll train again this afternoon and tomorrow, but I feel confident," the 31-year-old son of former England batsman turned match referee Chris Broad, added.
"I've been playing county cricket since early April, so I've got quite a lot of red ball and white ball cricket in. It was great to have the intensity of a Lord's final, to play in it but also to put my body to the test."
First Published: July 4, 2017, 6:45 PM IST