Although all branches of the United States military are difficult, the hardest military branch is likely the U.S. Navy or U.S. Marines. Several military reports have data showing that Marine training is the toughest among the military disciplines. The number of injuries among Navy recruits is higher compared to that of recruits in other military branches.
Stress fractures for both recruits and troops already in the Navy are higher than for those in other branches. For instance, the number of fractures among recruits is 18 times higher than those among nonrecruits. The main causes of sprained ankles and broken bones are long marches, jumping jacks and runs. Deep diving also causes bone crunching among the marines and helps make it the hardest military branch.
Additionally, participating in repetitive weight-bearing activities, such as marching and running, causes stress fractures. Weight-bearing stresses lead to hairline cracks, which cause stress fractures. Stress fractures occur in the lower legs and foot bones twice as often among the those in the Navy compared to those in other military branches.
However, the military has introduced new marine training aimed at reducing injuries by increasing the recovery time between several phases of the physical training. The Navy has made changes in its boot camp, including increasing the minimum hours of sleep at night. It also recommends a reduction in the marching distance for recruits during training. The best way to reduce stress fractures is to redesign the recruit training schedule to meet the minimum sleep and marching recommendations.