Running and carrying are why we have two legs, springy arches in our feet, big butt muscles, sweat glands across our body, no fur, short torsos, and why we can "lock" our hand bones into our wrist bones and generate abnormally strong forces with our middle finger. Other animals can't carry well, but humans are "extreme" in our ability to hoof heavy items from point A to B, according to a study in PLOS One. Running and carrying are, quite literally, our evolutionary advantages. And it's made them some of the fittest band of humans to walk the earth. And rucking works these parts as an integrated system, which can help you avoid injuries, according to research conducted for the military. Consider back injuries: About 80 percent of Americans will experience back pain sometime in their life. But researchers in Canada believe rucking can help relieve and prevent back pain because the weight "pulls" your spine into a position that compresses its discs less. Perhaps most importantly, rucking delivers cardio benefits equal to easy running, according to researchers at the University of South Carolina, as the extra weight elevates your heart rate more than walking alone. Rucking too heavy, fast, or too much too soon can lead to overuse injuries. Particularly if you've neglected upper-body strength training, you should ease into the weight or else your shoulders might become overly sore. Start with 10 to 25 pounds and work your way up. Any old backpack should be able to hold up to 30 pounds. As you reach heavier weights, you may need a sturdier pack. Place the pack on your back, cinch the straps to about midway, then go for a walk or hike for as long as you'd like. #trevorkashey #trevorkasheynutrition #lifehack #rucking #lifetips #mindset #selfrespect #dosomethinguseful #lifeadvice #goruck #gorucktribe #goruckgames #michaeleaster #comfortcrisis