Warriors have built on their impressive opening-day victory over champions Leinster with convincing wins against Cardiff Blues, Newport Gwent Dragons and Connacht.
Alongside Ospreys they have established themselves as GUINNESS PRO12 pacesetters - and will be looking to keep the ball rolling against Benetton Treviso on Sunday.
And Scottish international Fusaro believes hard work has made the Warriors one of the fittest and fastest teams in the league.
"It's been a brilliant start with four wins from four and two bonus points, especially against the Dragons when we went down to 14 men," the flanker told the Daily Record.
"That was testament to the character of this side, and the boys were very courageous in that game.
"With all the hard work we did in pre-season, we're starting to put teams out in the last 20 minutes of games. We're feeling fit and we're feeling strong so that's very good.
"All that work that we put in then, and in training now, allows us to play a fast expansive game. That's showing in our league performances now and we're getting the results.
"It will be a tough encounter with Treviso. The Italians are always very big and physical and it's a game we'll be taking very seriously again."
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