What did you set out to do with your training this offseason?

CK: To get faster and better at everything, from my drops to accuracy to the playbook. I took one week off after the Super Bowl, then went down to Atlanta. We train most of the day, from 8 a.m. until 2 p.m. Coach [Jim] Harbaugh was a little worried I was going to get too jacked -- he talked to me about that -- but I think the biggest thing for a quarterback is making sure that as you get bigger, you keep your flexibility. You have to train hard and be strong while staying flexible and limber, so I'm trying to find that balance. I've been trying to make my legs stronger and more explosive and build more fast-twitch muscles. I've been running with bands and chains, I've been pushing sleds, I swim tied to a bungee. Will I be faster this year? You'll just have to wait and see.

What do you think is your best physical skill?

CK: It would have to be my arm. A strong arm along with knowing where I want to throw the football can be a deadly combo. Teammates tell me to bring it down a notch in practice or that their hands are hurting. Randy Moss told me I was the first person to ever dislocate one of his fingers. That happened during my first "Monday Night Football" game. That was crazy to hear because he's played with Tom Brady, Brett Favre, Daunte Culpepper -- quarterbacks with strong arms. He wasn't upset, more impressed. I think being a baseball pitcher helped my arm health. Throwing year-round kept my arm strong; it kept it conditioned. I topped out at 94 mph [pitching] in high school, and at the combine I clocked 59 with a football.

If you could change something about your body, what would it be?

CK: I wish I could get my legs bigger, but I can't put weight on them. My legs will get stronger but never grow. One of my good friends, Kyle Williams, has huge calves, so I mess with him and he messes with me because my legs are skinny. We have opposite problems.

What is your favorite thing to do to train?

CK: I look forward to sprint work for the simple fact that you get to compete and see who is faster. Every rep, you are out there trying to win, trying to beat your teammates. It's bragging rights. Even between reps there's a little back and forth, and that only intensifies the workout and makes sure everyone is going hard.

When I lift, I try to do as heavy as possible until I can't do it anymore. That helps me endure a season, and that's what separates me. If we're doing sets of five, it's not, "All right, that was good, I'm comfortable with that." No, I'm going to do it until my arms are about to give out or my legs are about to go. I think that earns the respect of teammates. They see I'm not just going in there, keeping my shoulder healthy and leaving. I think they appreciate that I'm trying to get stronger the same way they are.

What's the biggest challenge you face with your body?

CK: Making sure I'm feeding my body the right things. I was a candy junkie and ate a lot of fast food in college, and that's something I'm trying to cut out. From time to time I'll relapse, but I stay away from junk as much as possible. And I can eat quite a bit. I don't think I'd have any problem eating a whole pizza by myself.

Why are your tattoos so important to you?

CK: It's what I believe in. They're part of me. They relate to my faith or things that shaped who I am. My favorite right now is "My gift is my curse," written on the inside of my arm. That's applicable right now. There are great things I can do in this position, great opportunities, but there are also things I have to sacrifice. For instance, time with my family. And privacy, being able to go to the grocery store or mall and just hang out -- that's not something I can do. It's unbelievable how different it is right now compared to last year. A lot of camera phones, a lot of pictures, a lot of signatures.

I didn't just walk into a tattoo shop and say, Hey, I want that thing on the wall. All my tattoos were planned more than a year before I got them. I think if people knew what tattoos mean to people, they wouldn't feel the same way about them. Kissing my biceps started from the whole tattoo controversy. I'd kiss "Faith" on my right biceps. That was my way of showing that I love my tattoos, and regardless of what anyone else thinks, they mean something to me. They're more than just ink on my body.

What fuels you?

CK: A lot of people say last year was a fluke. They say defenses are going to figure out how to stop our offense, and we can't do it again. That constantly drives me. Anytime I'm told I can't do something or told someone is better than me, that motivates me to prove them wrong. It doesn't matter what I'm playing -- tic-tac-toe, chess, Monopoly -- I'm playing to win. I don't want last season to be an outlier. I don't want to be one of those players who had a good year and comes back and has a bad one. I want to be similar to the Tom Bradys of the world -- every year you get a great year out of them. They go out there and perform at a high level.