Dublik (1987) reviewed information gathered by the Walter Reed Army Institute of Research. The members of seven infantry battalions who participated in Operation Urgent Fury in Grenada were interviewed. The general conclusion was that many soldiers were overloaded. Too few commanders enforced load discipline. A soldier stated in the interview:
“We attacked to secure the airhead. We were like slow-moving turtles. My rucksack weighed 54 kg. I would get up and rush for 10 meter, throw myself down and couldn’t get up. I’d rest for 10 or 15 minutes, struggle to get up, go 10 more meters, and collapse. After a few rushes, I was physically unable to move, and I am in great shape. Finally, after I got to the assembly area, I shucked my rucksack and was able to fight, but I was totally drained.”
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I'd be curious what the time on that 10 meter rush was... guessing it was more than 3 seconds.