Soldiers might bitch about it in training,but you ain't going to find any that will bitch about carrying all the ammo,grenades, and armor they put on and still stand up when going off to battle. For example,my basic load of ammo and explosives was 38 loaded magazines of .223 for my CAR-15,two canteen pouches full of the Dutch "mini-grenades",a white phosphorous grenade on one suspender,a K-BAR knife taped upside down on the other,and a anti-tank mine in my rucksack,"just in case".
I also had 4 canteens on my pistol belt,and more ammo in my rucksack. Back at the basecamp or launch site I needed help getting back on my feet if I had been sitting and leaning back against the rucksack while resting or taking a nap,but once the helicopters fired up and the adrenaline fired up,I could run fast enough with all that stuff on to take down small trees,and still have the scars on my arms to prove it. Of course,some of them may have been from shrapnel. At that time your attention tends to be focused on other things.