I recently came into the possession of a OneFitWonder Sandbag System and have had a week to play with it. Upon opening the box it came in I quickly saw it was very sturdy construction, I mean... it has to hold 100lbs of sand AND get moved around a LOT.
Each of the carriers have a thick hook and loop fastener strip on the outside AND another hidden on the inside to make sure the sand stays in.
The bag that the carriers go in has a military grade zipper and a flap outside of the zipper that is again a generous width of hook and loop fastener.
I chose to leave some extra room in the filler bags to ensure the sand would shift around making any exercises attempted that much more difficult, three carriers are included with the 100lb system which you fill with sand and then place inside the duffle.
It was easy getting the three filler bags into the duffle but it took a good minute of messing with it to actually be able to zip it up, the sand really didn't want to work with me, once I got it zipped though the bags move around good inside the duffle and the sand moves around well inside the filler bags.
Above I look pretty grumpy, it was just one of those days (and hey, the sun is in my eyes for crying out loud). Getting it to one's shoulder at about 80-85lbs is actually relatively easy (for me anyway) but once it's up on your shoulder you certainly feel it pulling that side of you toward the ground, the first day I walked around with it on each shoulder for several minutes and the following day my core was screaming at me "ermagerd we sore, y u do that 2 us?!"
Lunges are already difficult for me, my rather generous gut tends to make me a bit unstable, add one of these sandbags to a shoulder and it's a chore to stay upright.
Above I TRIED to press it, it didn't work. In fact I'm doing my best just to hold it up there. It's not that the weight is hard to get above my head, it's the simple fact I'm holding the handles for dear life and it STILL is sliding all over the place, ahh the joy of sand.
Once you get it over your shoulders you quickly find gravity is a harsh mistress, she's pulling you down with a vengeance. This is on my way down in a squat, I can get hips below parallel easily (I can without the weight too, I'm oddly flexible for a fat man) but keeping a good form with the sandbag on your shoulders isn't very easy, you tend to pull your chest in and push your back out, no bueno. I probably should do that with less sand in until I get used to the weight shifting but eh I was only squatting with the sandbag system for the photo, I get enough weighted squats in at CrossFit317.