Sudden Trapezius Muscles

I think that's what they're called.

I've never had much by way of visible muscles on my torso before, my arms and legs would be quite toned from drumming but until recently I had a beer gut :rolleyes:. I have good upper-body strength due to having worked in jobs where a great deal of manual handling was involved. Recently I spent a while moving and organising a lot of stuff during a handover to a position working from home, so that was a couple of weeks of fairly intensive lifting and building shelving etc.

Just this week, I noticed that the muscles just where the shoulders meet the neck are much more pronounced than they used to be.

In terms of exercise, this year I've started to cycle everywhere and improve my martial arts skills but other than the brief stint moving things I don't think I increased the intensity of my upper body workout at all. Does anyone have any suggestions as to something I can formally do to keep these muscles well developed now that they're there?!! Also is it possible to drink a lot of beer and not have a beer gut because the homebrew will be ready next week.