SANTA CLARA -- Defensive end Nick Bosa is slimmed down this season, which has led directly to a bigger season for the 49ers.
Bosa was coming off a bilateral core muscle injury that required season-ending surgery during his final college season. The 49ers selected him with the No. 2 overall pick in the 2019 NFL Draft.
Bosa registered nine sacks as a rookie and was the NFL Defensive Rookie of the Year despite feeling as if he had a lot of room to get better.
“I came into my rookie year a little stiffer than I wanted and a little bigger,” Bosa said on Friday. “Obviously, it was a great year, but if you look at my body from the first game to the playoffs, it’s pretty different from how I was moving.”
Bosa’s second season was cut short after sustaining a torn ACL in Week 2.
He put in the work during physical therapy and offseason training to come back even better for training camp this summer.
Bosa’s playing weight is at 255 pounds -- down from 263, he said. And even though it might be imperceptible to everyone else, Bosa said his massive quadriceps are actually slimmed down this season.
“My legs were bigger my rookie year,” Bosa said. “And after my injury they’re a little smaller, I think. And my diet is different. I’m a little thinner all around, and I have better mobility. So my legs cycle faster and I move better.
“So, technically, I ended up faster and better. But I think that’s just me honing in on more things because I know I want to be the best. I don’t want to leave anything out there.”
Bosa said he does nothing in his training designed to increase the size of his legs. Bosa’s leg days in the weight room consist of front squats, Romanian dead lifts and step-ups, he said.
“My dad’s quads are huge,” Bosa said of his father, former NFL player John Bosa. “Mine are just genetically big. I don’t lift body-building type reps. I’m not doing three leg exercises or leg extensions to try to get big legs.”
Bosa said he is not obsessive about his size or playing weight, but he does not even need to step on a scale to know where he checks in. Thanksgiving Day was especially challenging.
Bosa enjoyed a feast at the home of teammate George Kittle, whose chef from Nashville prepared roasted beef and chicken, along with dessert of apple pie.
“It was ridiculous,” Bosa said. “I’m feeling it today. . . . It takes me a day to get back to feeling normal.”
Bosa has been the best player on the 49ers' defense. He is one of just eight players in the NFL with 10 or more sacks. He also has 15 tackles for loss in 10 games.
He does not want to get too far ahead of himself, but Bosa clearly believes he is capable of doing much more in a season when he is not working on re-strengthening himself after returning from a significant injury.
He will again work with Todd Rice, who also trains Bosa's older brother, Joey of the Los Angeles Chargers.
“I think even after this next offseason — obviously, I’m not thinking about that yet — but after this I’ll keep stacking upward,” Bosa said.