I have this flea market single sling backpack that have one compartment that I put water, food and phone in when I go on a run. I always had it and it's causing me no problem when I run before. I started lifting recently so I thought that the back pain was because of lifting.
But yesterday I when on a light run without it, everything was fine. Today, I ran with it on, after around a mile my back started to have this ache like it's completely fatigued.
It actually happened a couple times before. I usually put a liter bottle in, on hot days I put another half liter.
It's a single compartment bag, so everything kinda weight down to the bottom of the bag, which feels annoying. And after climb up and during the mount, or when I run fast, the bag just sag to one side, which couple times almost throw me off balance.
I like single sling because I guess I can roll with them on ( I wanted to get a left handed single sling so I can roll on my right side,but now not so much lol).
Did anyone have this problem? Any recommendation for back pack that I could put two bottles, a phone so that it doesn't jump around inside the backpack, and I can probably roll with it on?