You might want to keep quiet about this at a bodybuilding competition - but having bigger muscles does not necessarily make you any stronger.
Scientists at the University of Mississippi, reviewing existing studies, suggest larger muscles do not reflect how much someone can lift.
The proof comes in research which shows people who abandon the gym can hang onto the strength they have built up for months, even as their muscles shrink.
The experts also say that lifting both lighter and heavier weights create the same size of muscles.
The findings challenge many of the assumptions upon which traditional exercise programmes have been based.