The Walking Lunge is an excellent lower body developer synergistically targeting all the muscles of the lower body whilst also providing a great dynamic stretch to the hip flexors.
Start in the standing position and take a big step forwards
As your front foot lands drop down into the lunge position keeping your front heel grounded
Drive upwards using your front leg and take a big step through with the rear leg
Repeat as you travel forwards
Keep your knees tracking in-line with your feet for the duration of the exercise
Place your hands on your head to increase the balance demands