The Side Lunge is one of the best functional exercises around. Functional exercises are exercises which work your body in multiple planes of motion like activities of daily living. Alongside squats, lunges, the Side Lunge is particular should be one of the base exercises in your fitness program regardless of your goals.
The Side Lunge is an excellent lower body conditioning exercise that can help improve lower-body strength and muscular endurance in multi planes as well as improving your core conditioning, balance and stabilization for any specific movement patterns.
1. Stand with your feet hip width apart. Hold the kettlebell by the handle with both hands. Make sure you have a quadruple extension – ankles, knees, hips and torso. (See Fig. 1)
2. Step to the side with one leg and descend into the lowest lunge possible aiming to allow the bottom of the kettlebell to touch the floor on the inside of the foot. Make sure you keep the opposite leg straight. Your feet should remain parallel and facing forward. (See Fig. 2)
3. Keep the weight onto the heel of the leg you stepped to the side with, drive the hips up and step back in to return to the start position.
4. Repeat the movement from point 2 on the opposite side.

Side Lunge
Fig. 1

Side Lunge
Fig. 2

To ensure your safety and stability make sure your abdominals are drawn in, your back remains straight, and your glutes and quadriceps are tense throughout the motion.