I’ll probably definitely have to get one if I continue this physical regime till 40-45. I call bullshit. I’ve been a distance runner since I was 12 (and I’ve d

I’ll probably definitely have to get one if I continue this physical regime till 40-45. I call bullshit. I’ve been a distance runner since I was 12 (and I’ve done my share of 100 mile weeks) and if there’s a genetic component, see also: Mom. I’m in my 50s, and knees are the least of my worries. Dad’s in his 70s, and his heart limits his running, not knees. He’s not nearly as hard-core as I, but he’s got some marathons under his belt. All anecdata, but probably as grounded in reality as your badminton buddy. Though I admit ignorance to what a shuttler is, so maybe that’s what your buddy is worried about. It ain’t necessarily the running, though. Do take care of those knees, though. Don’t ignore problems, just like anything else. I’m just saying that though it could be a problem, it is not engraved in stone as far as I can tell from what I’ve read.