The New Year is here and you are ready to commit! Change up your workout for 2014 by adding one or two non-consecutive days of high-intensity interval training (HIIT) to your exercise plan. Why HIIT?

1. It’s efficient. Just 15 to 30 minutes is all you need for great results!
2. It increases lean mass. HIIT provides an increase in the production of testosterone in men and growth hormone in women, helping to not only maintain but also gain some muscle!
3. It’s adaptable. High intensity is not the same for everybody. By picking the correct exercises and work/rest ratios, anybody can work at their own version of “high intensity.”
4. It boosts your metabolism. HIIT targets all three major energy systems, with an emphasis on anaerobic training.
5. It's FUN! Time flies while completing these fast-paced and challenging workouts!

Careful! As fun as high-intensity interval training is, you must build up to it to avoid overuse injuries and overtraining. Before completing a set of exercises at maximum intensity, make sure you are doing the exercise properly; a trainer can help! Also, don’t do too much too soon. Begin with one round of this workout and work your way up to three. Be sure to include some steady-state cardiovascular work and regular strength training on the other days of your workout week.

The following eight exercises can be completed one of two ways. If you are new to high-intensity interval training, perform the traditional HIIT format of 1:3 work-to-rest ratio, which is 30 seconds of hard work followed by a on-minute rest before beginning the next exercise.

If you are already in interval-training shape, try doing this workout with a Tabata timing protocol: 20 seconds of hard work followed by 10 seconds of rest while transitioning to the next exercise.

This workout can be done up to three times with a five-minute rest break between rounds.

Warm-up 

Perform 30 seconds of each of the following exercises at an easy-to-moderate intensity.

-Body-weight Squats: Warm up the hips by challenging your range of motion while squatting.
-Alternate Leg Runners Stretch With Opening: Open up your hip flexors and rotational muscles by placing both hands on the inside of your front leg in a deep lunge. Reach the outside hand toward the sky, trying to create as much distance from one hand to another, while continuing to hold the runner’s stretch.
-Arm Swings (Forward and Backward): Loosen up your shoulders for the pressing and pulling movements to come.
-Lateral Lunges: Begin in a wide stance with toes pointed forward. Place one hand directly on top of the other in front of your body to brace your core, and sink your hips side to side.

The Workout

Box Jumps

Select a box height that is both challenging yet safe for your skill level. Jump onto it, and back down, landing with soft knees. (Option: Alternating Leg Step-ups)

Kettlebell Hard Swings

Select a challenging weight that does not compromise your form and initiate your swing with the hips. Brace the core and squeeze the glutes on the top of the swing and maintain a good hip hinge on the bottom. (Option: Dumbbell Straight-leg Deadlifts)

Lunge Switch Jumps

Begin in a strong and stable lunge. Press off of both feet and drive from the glutes as you jump and switch legs in the air, landing in the opposite lunge. (Option: Step-back Lunges)

Renegade Rows

Maintain a solid plank position (no saggy hips!) and create a wide base of support with your feet. Alternate rows from one side to the other with minimal rotation. (Option: Perform a hand plank with arm and leg raises)

Diagonal Med Ball Slams

With the medicine ball overhead, engage your core and slam the ball down to the ground just to the outside of your right foot. Catch the ball on the up-bounce and immediately lift it overhead. Slam it down once again, this time to the outside of your left foot. (Option: Medicine Ball Wood Chops)

Battling Rope “Over the Top”

Hold the battling ropes in an overhand grip, beginning on the left side of the body. Lift the ropes up and over an imaginary fence in front of you and slam them down on the right side of your body. Repeat in the other direction, while maintaining a solid hip hinge and soft knees.

Plyo Push-ups

Lower down into a perfectly planked push-up (say that five times fast!). Drive through the floor as you launch your upper body into the air. Ensure you maintain the solid plank when you land and immediately bend your elbows for the next push-up. Want an added challenge? Try leaving the ground with both your hands and feet! (Option: Regular Push-ups or Knee Push-ups)

Battling Rope Underhand Waves

With an underhand grip on the rope, bend the knees and hit an athletic stance (no hunching!). Alternate waves with the rope as if beating your fists on a drum.