I think its a good idea to train your body, being a trumpeter.
I discovered "body building", weight lifting through my brother, an ex division one baseball player. I used to be a pretty good baseball player from t-ball through 9th grade, and then I stopped my athleticism to focus on "music" and trumpet playing.
But the last year or so, I really have tried to commit to showing up to the gym six days a week. At first I was really out of shape and could barely do anything! Right now, I feel my stamina has increased and I know how to "lift" a little better, without injuring myself.
I prefer to lift light and every now and then, will try to lift heavy. But lifting heavy is just not too enjoyable, unless you really want to show off and there is a lot of people around - could make it a fun social event.
But I have figured out that lifting light weight, with a lot of reps, is probably the way to go for now. I am feeling stronger and muscles seem a little more pumped.
So, I highly suggest, as trumpeters, that we train in some manner, on a daily basis, six days a week.
I do remember hearing that Miles Davis was into boxing at one time and that it helped him in his trumpet playing.
Keep the body strong, and I'm sure it will help the trumpet chops as well.