Can't find the time to exercise? Well, I'm going to let you in on a little secret: You don't need to work out for hours and hours a week to lose weight, build strength, and improve your overall health. In fact, you can complete a full-body workout in just 15 minutes—and you don't even need to go to the gym to do it. The key: compound exercises, which are double-duty moves that fire up multiple muscle groups at once, allowing you to maximise your limited workout time.

The following 15-minute total body workout consists of eight highly effective compound exercises that not only strengthen muscles in your arms, legs, and core, but also challenge your balance and coordination.

Equipment you need:You'll need one light set of dumbbells (1.5kg, or 2kg) as well as one heavy set (4kg or 5kg).

Directions: Perform each exercise 10 to 12 times, then move onto the next with as little rest in between as possible. Repeat the whole circuit two times. Do it three to five times a week.

1. Squat to shoulder press

How to do it: With a heavier weight in each hand, place your hands at your shoulders. Squat down. Rise to standing and then press your arms overhead.

Make it easier: Squat down to a chair, press the dumbbells overhead, then stand up.

Make it more difficult: Start with your arms straight overhead, lunge to your left as you bring the dumbbells down toward your chest. Press the dumbbells up as you push through your left heel to stand. Repeat on the other side.

2. Lunge to single-arm row

How to do it: Start with your left leg forward, right leg back, and a heavier dumbbell in your right hand at your side. Rest your left hand against your left thigh. Bend both knees and lunge. As you extend your legs and rise to standing, draw your right elbow up toward the ceiling, keeping it in close to your body. Do 10 to 12 reps, then switch sides.

Make it easier: Instead of performing a lunge with each rep, hold as deep of a lunge as you can with your back slightly bent over the front leg. As you hold here, perform the single arm rows.

Make it more difficult: Add a lunge extension at the end of each rep. As you complete the row and the back knee locks out, shift your weight to the front leg and squeeze the opposite butt cheek. Lift that rear leg up and behind you then return back to the high lunge position.

3. Deadlift to bicep curl

How to do it: Stand with a heavier dumbbell in each hand, your feet a hip's distance apart. Sit back as you lower the weights to your shins, keeping them close to your legs. Then as you stand, curl your hands toward your upper arms.

Make it easier: If you need more back support, use the wall! With your arms at your sides, place your back against the wall and sit into a squat. Stand up and perform the bicep curls.

Make it more difficult: Instead of doing a regular two-legged deadlift, do single leg deadlifts. Shift your weight to your right leg. Keep a slight bend in the right knee. Lean your torso forward and kick your left leg back. Once you reach mid-shin height, keep balancing on that right leg and perform the bicep curls. Do all the reps on the same working leg or alternate each rep.

4. Curtsy lunge to upright row

How to do it: With your arms at your sides and a light dumbbell in each hand, plant your left foot on the mat. Step back and to the left with your right foot. Bend your right knee, and curtsy. Step your left foot back in line with your right, toes pointing forward, as you lift your elbows into an upright row. Then curtsy with the other leg. Do 10 to 12 reps on each side.

Make it easier: Instead of curtsying side-to-side, step back and bend that back knee as low as you can with ease.

Make it more difficult: Add a side leg lift at the end of each rep. So say you are curtsying to your left (right leg behind). Come back to standing, perform the upright row, then as your shifting your weight onto your right foot, lift your left leg straight and up to the side. Then go right into the right side curtsy.

5. Bridge to headbanger

How to do it: Lie on your back with your knees bent and arms extended over your chest, a dumbbell in each hand. Press into your feet and lift your butt into a bridge. Bend your elbows and bring the weights to your ears. Extend your arms and lower your butt. Repeat 10 to 12 times.

Make it easier: Break up the movement. With your arms straight and the dumbbells over your chest, lift your hips up and drop them back down to the floor. Then perform the headbanger.

Make it more difficult: Do single leg bridges with the headbangers. You can alternate legs each rep or perform half the reps on one leg before you switch.

6. Push-up to plank jack

How to do it: From a plank position with your hands under your shoulders, bend your elbows and lower your chest into a push up. Press back up and jump your feet out to the side into a jack. Repeat 10 to 12 times.

Make it easier: Hold the plank position and do toe taps instead of the plank jack: Tap your left big toe out to the left; place it back to center. Tape your right big toe out to the right; place it back to center. This is one rep.

7. Russian twist into a pike

How to do it: Sit on your mat with your knees bent. Lean back and lift your feet a few inches from the floor, so you are balancing on your butt. As if you were holding a ball at your navel, twist your torso to the left, then the right, then the left. Return to center, extend your arms. Bring your arms back to your navel and twist to the right, left, right, left, and then center and reach. Do 10 to 12 reps.

Make it easier: Nix the pike and do Russian twists.

Make it more difficult: Keep your feet off the ground and your knees locked out throughout the whole exercise.