As someone who has trained in body armour, and regularily carries a 50-70lbs pack for long amounts of time on steep terrain I can give you this little bit of advice: Do not run with weight above your knees, nor jump, over time this will screw your knees up worse then you can imagine. I ruck alot (a very brisk walk) and even just this you can feel alot of extra pressure on your knees, granted this is 50-70lbs and you are talking around 20lbs I take it? Imagine how much force you hit the ground with while you are running with no weight. Now imagine adding 20lbs to that, and seeing as a large number of people run on concrete for lack of a dirt trail, it might not feel like it at first but over time this will mess your knees up, ask any retired infantry man and he will tell you the same. I do however train with my ruck on as well as armour, while using it for body weight exercises (push ups, pull ups, dips, squats, etc) I find it helps me alot, of course some of my goals are to be able to move faster underweight so this may not be the gains a normal traceur is looking for. If you do start down this path, I would suggest investing in joint health supplements, I would suggest that for any traceur anyways but definatly for someone carrying excess weight.