Meanwhile, working conditions for the infantry have changed considerably in the past two decades. The biggest change is the equipment that must be carried. Until the 1980s, you could strip down (for actual fighting) to your helmet, weapon (assault rifle and knife), ammo (hanging from webbing on your chest, along with grenades), canteen, first aid kit (on your belt), and your combat uniform. Total load was 13-14 kg (about 30 pounds). You could move freely, and quickly, like this and you quickly found that speed and agility was a lifesaver in combat. But now the minimum load carried is twice as much (27 kg) and, worse yet, more restrictive.

Over the last decade, this has already translated into some dramatic changes in training. In Iraq, troops found they were not in the best condition to run around with all that weight. Plus, the vest constricted movement and that took time to adjust to. Commanders complained about troops not being properly trained, and that led to a series of changes in basic and unit training. The big change in basic was to condition troops to handle the heavy weights they would be carrying for extended periods of time. This was particularly critical for non-combat troops (especially those operating convoys) outside of camps (where you usually didn't have to wear armor and combat gear). New exercises were developed. Infantry troops got several months of additional training after basic and had plenty of opportunity to adjust to moving around wearing 14 kg or more of gear.

This all began when more essential equipment was added in the late 1980s and early 1990s. The biggest, and heaviest, problem is body armor. Although the new armor offered better protection it was heavier and bulkier, thus inducing fatigue and hindering mobility. This often led to battlefield situations where a less tired, and more agile, infantryman could have avoided injury. Military and political leaders usually do not appreciate this angle. But the troops do, as it is a matter of life and death for them.

Currently, the lightest load carried, the "fighting load" for situations where the troops were sneaking up on the enemy and might be involved in hand-to-hand combat, is 28.6 kg (63 pounds). The "approach march load," for when infantry were moving up to a position where they would shed some weight to achieve their "fighting load", is 46 kg (101 pounds). The heaviest load, 60 kg (132 pounds), was the emergency approach march load, where troops had to move through terrain too difficult for vehicles. As in the past, the troops often ignored the rules and regulations and dumped gear so they could move or keep moving.

In Afghanistan, the problem is made worse by the high altitudes (up to 5,000 meters) the troops often operate at. The researchers found that in Afghanistan, even though the infantry were in excellent physical shape, troops would sweat nearly 59 cl (20 ounces) of fluid an hour while marching at high altitudes in bright sunlight in moderate temperatures. That meant more weight, in water, had to be found to keep these guys going.

While troops complained about the new protective vests they valued the vests in combat. The current generation of vests will stop rifle bullets, a first in the history of warfare. And this was after nearly a century of trying to develop protective vests that were worth the hassle of wearing.

Soldiers have been marching long distances for thousands of years. But that has changed, it really has. In the past, troops have carried heavy weights in combat but they did not have to be as mobile as modern troops. The troops appreciate the new physical training more than some of their commanders. Part of this is that the new routines emphasize some exercises that resemble yoga and Pilates. Both of these physical training methods are relatively new in the West but have long served to provide the limberness that is so vital for 21st century combat.

But new training has not been able to restore the mobility troops had in previous wars and the troops miss that. While less likely to die in combat, troops are nearly as likely to be wounded or maimed as their predecessors in World War II and Vietnam. The troops want their mobility back.