help me with this sentence

[sympathy]

After three months in a cast, Stan's biceps had atrophied somewhat; however, he was sure that if he pumped iron for a while he would soon build them up

Could you please explain this sentence for me?

What does it mean ?

What is "in a cast" ? What is the atrophying of biceps ? What is pumping iron ? What is build them up ? I don't understand a word.

Thanks

 

[Anglika]

After three months in a cast, Stan's biceps had atrophied somewhat; however, he was sure that if he pumped iron for a while he would soon build them up

Could you please explain this sentence for me?

What does it mean ?

What is "in a cast" ? What is the atrophying of biceps ? What is pumping iron ? What is build them up ? I don't understand a word.

Thanks

Stan has evidently had an accident resulting in a broken arm, which means he has been in a plaster cast for three months. As a result, his muscles in the upper arm have lost strength and have shrunk. He believes that if he lifts weights, he will soon get back his strength.

Body builders "pump iron" to make their muscles abnormally large: http://tinyurl.com/28cbf3

 

[sympathy]

Thanks so much.