Although it is recognized that the health benefits of physical activity and exercise far outweigh the risks of getting hurt, injuries are the greatest threat to our readiness across the military spectrum. Weight-bearing and exercise-related activities account for 50% of these injuries.  

Wear of Improved Physical Fitness Uniform (IPFU)

ALARACT 239_2011  (Password protected - AKO)  states:                              

"SHOES THAT FEATURE FIVE SEPARATE, INDIVIDUAL COMPARTMENTS FOR THE TOES [ARE] PROHIBITED FOR WEAR WITH THE IPFU OR WHEN CONDUCTING PHYSICAL TRAINING IN MILITARY FORMATION"