"I just had to gain a bit more weight," he said. "Just so I can anchor when I get those bull rushes and things like that. I talked with my coaches and the front office and they want me to get a little bit bigger."
The 6-foot-5 Bolles plans to stay in the 300-305-pound range this season.
"I feel more explosive and powerful [at that weight]," he said. "Probably no more than about 308 is what I'm feeling. I feel confident there. My body feels good and I'm looking forward to the season."
During his rookie season, where he started all 16 games, he played at about 290 pounds.
"There were rocky moments," Bolles said of his rookie season. "Rookies have to go through certain things. I watched a lot of film trying to fix my mistakes. I'm trying to do everything I can possible to get ready. Knowing that we've got a new quarterback in, I've got to be ready to protect him. I'm excited for that and I feel really good going into Year Two. I feel a lot calmer and collected. The offense is pretty similar. The thing is just new terminology. I'm just looking forward to it and I'm excited to see what happens this season."
The Broncos are counting on the former first-round pick to take a huge step forward in his sophomore campaign.
"Year 1 is different from Year 2," he said. "'This is where you make your big leaps and bounds is what everyone tells me."
After coming in raw last season, Bolles is ready to go thanks to an understanding of what it means to be a professional in the NFL.
"Just going out there and playing fast is the thing I'm going to focus on, which is going to help me stay focused," he said. "Also, to move my feet. We changed up our pass sets and everything like that with [offensive line-tackles coach Chris] Strausser. He did a great job with all of our tackles. Just trusting him, trusting in the process and knowing that if my feet get there before my hands I'm going to be alright."