i've started running with about ten lbs on my back 2-3 times a week, for 2-4 miles depending on how i feel. any harm in this? also, i'm not an mma competitor, i'm just looking to stay fit & increase endurance.
not sure if the extra 10lbs will be significant enough to cause probs, but remember running period puts more of a strain than say walking.
arguably, those weighted vest cause probs, but the weigh more than 10lbs, or at least people are putting more than 10lbs in the vest.
have you ever tried farmers walk with Dumbells in each hand, or even sandbag carries.
i understand these can be as taxing as sprints contingent on the weight of the dumbells and sandbag, and you walk, not run with these.
just my .02.
If your running with weight build up slowly and try avoid running on concrete.
Run as you are now (2-4 miles/10lb) and put the weight up 5lbs every 2 weeks if you feel it isn't giving you the workout you need.