If you think you don't have time to workout, I am going to say, "You do". It's the intensity of your workout that's key, especially if you don't have much time. A short-burst, high-intensity workout boosts your metabolism and tones muscles.

Below is a high intensity workout that can be done and will hit all major muscle groups in one session.

Beginner Squats: for Thighs
If you're new at this, get started with a beginner version of squats using an exercise ball. Stand against a wall with the ball at your low back, feet hip-width apart and out in front of your hips. Slowly lower your body by bending the knees, dropping glutes toward the floor; slowly move back to the starting position. Your knees should remain over your heels. Your thighs will make a 90 degree angle with your lower legs at the bottom of the position. Perform 10 repetitions.

Squats: for Thighs
Once you're ready, try squats without an exercise ball. Keep your feet shoulder-width apart and your back straight. Bend your knees and lower your rear as if you were sitting down, keeping your knees over your ankles. To target more muscle groups in less time, add an overhead press at the same time. With a dumbbell in each hand, rise from the squat position and push weights overhead. Really focus on good form. Perform 10 repetitions.

Forward Lunge: for Thighs
Standing with feet hip-width apart, take a big step forward with one leg, then lower your body toward the floor, front knee aligned with ankle, back knee pointing to the floor. Return to the starting position, and repeat by stepping forward with the other leg. For more challenge, hold a free weight in both hands and complete the lunge with a rotation in the torso, twisting the body toward the forward leg. Perform 10 repetitions on each side.

Romanian Deadlift: for Hamstrings
To perform a deadlift holding a barbell or dumbells,stand up straight with feet hip-width apart. Fold at your hips, moving the hips backward as you lower your upper body parallel to the floor. Keep the legs straight with a slight bend in the knees 9do not lock out the knees), and keep the back level and the spine in neutral. Lower the weight to just below your kneecaps, then slowly return to the starting position. Perform 10 repetitions.

Push-Ups: for Chest & Core
Push-ups strengthen the chest, shoulders, triceps, and core muscles. Lying face-down, place hands a bit wider than your shoulders. Place toes or knees on the floor, creating a smooth line from shoulders to knees or feet. Keeping core muscles engaged, lower and lift your body by bending and straightening your elbows. To boost the workout intensity, put a stability ball either under the hips, knees, or feet. Placing the ball under the feet is the hardest. Perform 10 repetitions.

Chest Press: for the Chest
Lying face-up on a bench, with knees bent and feet on the bench or feet on the floor, spine relaxed, press a barbell or dumbells from your chest toward the ceiling. Extend your arms but don't lock the elbows, and move slowly in both directions, keeping shoulder blades on the bench. For an extra challenge, do the chest press with your head and upper back on an exercise ball. Perform 10 repetitions.

Bent-Over Dumbell Row: for Back & Biceps
The bent-over row works all the major muscles of the upper back, as well as the biceps. Begin the exercise in a bent-over position with your back flat, one knee and one hand on the same side of the body braced on a bench. Hold a free weight in the other hand with arm extended. Lift the weight toward the hip until the upper arm is just beyond horizontal, then slowly lower weight to the starting position. Perform 10 repetitions.

Shoulder Press: for Shoulders
A shoulder press works the shoulder muscles and can be performed standing or seated. For extra back support, use a bench with a back rest. Begin with elbows bent and dumbell weights at the shoulders. Slowly reach toward the ceiling, keeping the elbows under the hands. Do not shrug the shoulders when pressing; slowly lower back to the starting position. Perform 10 repetitions.

Cable Lat Pull Down: for Upper Back
Using a cable machine, sitting straight with a neutral spine, slowly pull the bar down past the face and toward the upper chest. Lean back only slightly as you pull the weight down. Control the weight on the way back up. Perform 10 repetitions.

Bicycle Crunch: for Core & Abdominals
Lying on your back on the floor, fold knees toward the chest and curl the upper body off the floor. With hands lightly placed behind the head, slowly rotate upper body to the right while drawing the right knee in and reaching the left leg out. Then rotate left and pull the left knee in and extend right leg out. Focus on bringing the shoulder toward the hip (rather than the elbow to the knee), and keep the opposite shoulder off the floor. Perform 10 repetitions.

Side Plank: for Core or Abdominals
For another abdominal alternative (one of my favorites!), lie on your side with a bent elbow directly under your shoulder, and use your torso muscles to lift the body up into a side plank. Then lift the hips higher, then back to the plank, then lower. Do as many as you can with proper form (actually, until I say relax!), then repeat on the other side.

It should not take you more than 30 min to do this routine. You can perform these exercises three times a week. I would also recommend changing things up after a month of this same routine.

Don't forget to do your cardio the other four days a week!

Train hard and eat smart!