Firstly, HAPPY NEW YEAR!
Now, and this is aimed mostly at us chaps out there but, ladies do please feel to read and comment. As we get a little older we start increasingly resembling hobbits. Maybe we don't have 2 breakfasts but we do start sprouting hair in places where it never was before, and there does tend to be a thickening of the waist, or a tightening of the waistband - damn those shops who keep making clothes smaller! - and an almost inevitable tendency to develop in the chest area... OK, we get moobs, and that is what I want to talk about.
We have the same basic anatomy and physiology as the ladies and, as such, we have the same support structure to support the moobs as ladies do boobs. And, just as with ladies, if the ligaments that support these stretches due to high-impact activities, and running is exactly that, they never go back - they stay stretched. What I am going to suggest is something that is quite common, but only spoken about in hushed whispers in dark corners, wearing a bra. It doesn't have to be a frilly and lacey one - although do feel free to if you wish - but a supporting sports bra. Buying online makes it a less embarrassing and painless experience, although I suspect that shop staff pay little attention to who buys what, so it can be done discretely without possible querying looks.
Yes, I do wear one. Why? I had testicular cancer and that threw out my body's hormonal balance and I developed 'up top'. Am I now used to it? Oh, yes. I even forget I have one on.
If you wobble when you run, buy one and try one. The difference is amazing.