I haven't done any real research on this subject, but from my experience, this isn't true. I think this is a point of view that has developed because many younger people who have muscular bodies are shorter. But don't get me wrong, I'm NOT saying that they're shorter BECAUSE they work out or have relatively large muscles for their age.

For the average male, it is relatively difficult to develop a lot of bulk before they have finished growing taller. Usually guys get taller and then they fill out. Those who stop growing in height early on, however, have a chance to fill out their body with muscles earlier than those who are still growing. That is why, at least I think, many younger musclar type guys are shorter, because they have already stopped growing taller and their bodies can focus all the nutritional intake on growing muscles.

Of course, there are always a few hormonal freaks who grow tall AND huge at the same time, but I think this is the exception to the rule.