How fast do you gain muscle?

I've been getting back into weight lifting and my arms were tiny and weak, but after going to the gym five days a week for the last two weeks, I can feel my muscles getting bigger. However, my step dad says it's not possible after such a short amount of time. Is there a noticeable difference after two weeks?

How to Lose Weight Like Tyra Banks

Recommended Answer:

The most you can realistically gain is about half a pound a week of lean muscle. That is if you are eating and doing everything properly. That is why your dad is skeptical. You arms are just getting more defined and the structure is becoming more rigid, making them look bigger. They are just sticking up more, but they haven't actually gained much mass.

Other Answers:

• ive been lifting hard for a year and im seeing some gains now. i doubt your are seeing actual muscle growth. it takes 5+ years of training to get 18+ inch arms and low body fat