A reverse lunge is a really nice progression from a simple lunge. This exercise works the glutes, legs and abs; particularly honing in on the hamstrings and Gluteus Maximus.
The weighted version of exercise is done with the kettle bells in the front rack position with the elbows tucked in and the palms close together.
You should begin with your feet shoulder width apart for a stable base, before stepping backwards and placing the toes of the back foot on the ground such that the shin is parallel to the ground and the knee is below the hip.
It is essential to keep the core tight and the front foot flat whilst looking ahead. Alternatively, you can swap the kettlebells in for a pair of dumbbells, or even a sandbag for added variation.