this is true. last year at school I took a fitness class where all we did was work out and run. between that and cross country by ski time came I noticed my legs were giving me more pop and I could take some gnarly hits without getting injured.
now I haven't worked out my legs since I was running in october and I blew my acl and mcl 2 weeks ago and the motherfucker just collapsed for no reason when I landed, even though I overshot by about 20ft but I didn't land on flat or anything.
definitely a lesson learned.