Many "bulked up" enlistees are surprised to find that pure gym strength doesn't translate well to military PT requirements; The military's need for a mix of cardio and strength endurance just doesn't match up well the slower paced reps/sets of bodybuilding style workouts- or the extra bodyweight that comes with it. There is an increasing interest in kettlebells because kettlebell training "hits" the same priorities as military PT.
Kettlebell training is basically a hybrid of the functional olympic style lifts (snatch, clean and jerk) with the higher reps found in dumbbell training; It's a very effective general fitness approach, but it's benefits to military PT really shine when it is incorporated as a complementary addition to the traditional bodyweight training trio of pullups, situps, and pushups. Physically, kettlebells are a steel or iron ball with a handle on it; Simple enough, but with some less than obvious implications. With the weight below the KB handle, KBs are much narrower than their dumbbell equivalents and allow the trainee to comfortably engage the hips,legs and lower back in the "swing" motion -sort of a high-rep deadlift. Once cleaned and "racked" to the shoulder, the round KB shape rests comfortably into the crook of the arm, allowing relatively higher weights with lower body motions like lunges and (especially) front squats.
Finally, when pressed overhead into the "lock" position, the KB's weight forms the bottom of a stable pendulum that allows the trainee to focus on the motion's form instead of overhead balancing ( you can even open-up your grip when the kettlebell is overhead). These simple kettlebell differences add up to the foundation of a surprisingly unique and effective set of motions and workouts. Trainees move the KB between these swing,rack and lock positions in a variety of motions and form fluid, high paced workouts with surprisingly heavy weights and high reps- hitting about the same strength-cardio mix that fast bodyweight circuits achieve with the additional functional benefits of flexibility and coordination of olympic lifting. The KB snatch, in particular, is a challenging all-in-one lift that draws on all the body's resources, and is often the basis for competitions based on the number of reps performed.
All this in a small ball that fits right in on the outdoor PT field. The kettlebell's features and advantages are introduced in several video previews on our site. Further, there's no need to abandon your traditional weight plates for expensive sets of single weight increment kettlebells; Adjustable kettlebell handles are available from Kettlestack which provide all the KB training benefits at fraction of the cost, along with a great range of weight adjustability. The key point is to try KB training and find out for yourself that it's an uniquely effective, challenging and fun training methodology with a great deal of carryover into military activities.