Its all how you train the body. When i started working out 4 years ago, i was only able to do 10 pullups (both neutral, close grip and wide grib) Now i can do easily 90 (30 of each variety). The key is to make sure that you use the ying-yank effect when working out ( for instance, i will work out my chest and back (shoulders included) together, biceps and tricpes together, and front legs and back legs). You have to make sure that the weight is similar on both sides (for instance, when i started, i could bench press 180 pounds and could only row about 145. Now i can do 250 bench and 235 row (still getting closer).

Even more important then weight lifting is calorie/ food intake. Ive seen other threads about this, so i wont have to get detailed, but i follow the abs power diet. Just make sure that while you are training to take in 50% protein, 40% carbs, and 10% fat. Then when cutting up, you take 60% protein, 30% carbs and 10% fat (all based on calories). If you want more of an explination, start another thread and ill post examples and meals that i eat throughout the day.