Here, Ebenezer Samuel, C.S.C.S., Men's Health fitness director, talks through the six main mistakes people make when it comes to building muscle—and how to fix them to pack on the size you want.

Here, Ebenezer Samuel, C.S.C.S., Men's Health fitness director, talks through the six main mistakes people make when it comes to building muscle—and how to fix them to pack on the size you want.