User object with lots of blocks

Permalink
Hello, i have a question,

I make a page "my account" for my members, and in this page, i have 6 blocks which use user Object $u -> new User();

How define only 1 object for my 6 blocks ? I try to define in the header but is not work :(

Can you help me please ?

Thank you and good day to you.

Emixam25