If you have the ever-popular office job that involves sitting at a desk for eight hours a day, it can wreak havoc on your precious body, creating tight hips and lower back pain.  Many stretches for your hips also stretch out your lower back, so these poses are like two for the price of one.  It will only take about four minutes, but that's all you'll need to ease tension.

Butterfly

• Sit on the floor, bend both knees, and bring your feet together.  Using your hands, open your feet up like a book, pressing your knees toward the floor with your elbows.  If you want more of a stretch, extend your arms out in front of you.
• Stay here for five breaths (about 30 seconds).

Half Happy Baby

• Lie flat on your back.  Bend the left knee and hold onto the outside edge of your flexed foot with your left hand.  Keep your left arm on the outside of your leg.
• Gently use your upper body strength to press the left knee to the floor below your armpit.  Try not to tense your shoulder or chest, but keep everything relaxed.
• Stay like this for five deep breaths, and then switch legs.
• Then do both legs together for another five breaths.

Pigeon

• Sit with your right knee bent and your left leg extended straight behind you.  If your hips are flexible, inch your right foot away from you.  Make sure your left hip is always pointing down toward the mat.  If it begins to open up toward the ceiling, draw your right foot back in toward your body.
• Rest your hands on your hips or walk your hands out in front of you, allowing your torso to rest over your right knee.
• Hold here for five breaths, and then repeat Pigeon on the left side.

Double Pigeon

• Sit on the floor with your legs straight out in front of you.  Bend your right knee and place your knee, shin, and foot on the floor so they're parallel with your pelvis.  Bend your left knee and place it on top so your knees, shins, and ankles are stacked.  You'll know you're doing it right when you gaze down and see that your legs make a little triangle.
• To make this pose more intense, place your hands in front of your shins and walk them out as far as you can, folding your chest toward your legs.
• Stay here for five breaths, slowly release, and then switch legs so your right knee is on top.

This total body workout is devoted to two types of exercises that you might despise because they're so hard, but man, they are effective at strengthening your thighs, butt, core, and abs!

It's just six moves, done for 30 seconds each, for a total of three minutes.  So you can do this short workout once, or repeat it a few times for a longer workout, whatever you have time for, or before your muscles give out — whichever comes first.

Squat With Overhead Reach

• Begin with your feet slightly wider than hip's width apart and toes pointed slightly outward.  Raise your arms up until your upper arms are even with your ears.  If this is too difficult, rest your hands on your hips.
• Keeping weight in your heels, sit back into a deep squat.  Make sure your knees do not go beyond your toes or roll in or out of alignment.  Keep your abs engaged as you squat.
• Deepen your abdominal engagement as you press through your heels to return to standing, completing one rep.
• Do as many reps as you can for 30 seconds.

Plank Jacks

Take your jumping jacks to the floor for this plank variation that not only works your arms, core, and lower body, it'll also get your heart pumping.

• Begin in plank position with your feet together.  Keep your upper body stable and engage your abs.
• Begin doing jumping jacks with your legs.  Hop them wide, then hop them together.  Jump as quickly as you want.
• Do as many reps as you can for 30 seconds.

Pulsing Plié Squat

Shake up your squat routine with the pulsing plié squat, which targets glutes and inner thighs.

• Start in second position, with your legs opened wide to the sides and your toes turned slightly outward.
• Placing your hands on your hips, bend your knees, going as low as you can.  Make sure your shoulders remain directly over your hips and your back stays in a straight vertical line.
• While holding this wide squat position, in a pulsing fashion, lower and raise your hips one inch for 30 seconds.

Up-Down Plank

Reps:  10 reps, each side.

Work your arms, shoulders, and core with this push-up variation:

• Come into a plank position with your legs straight and forearms resting on your mat.  Your feet should be hip-width distance apart.  Draw your navel toward your spine to engage your core and to avoid straining your lower back.
• Keeping your torso parallel to the floor, plant your right palm on the mat as you raise your body, so your right arm is straight.
• Repeat with left arm, so you're now in a straight-arm plank.
• Now, move your right forearm back onto the mat and then the left, lowering yourself back down into elbow-plank position.  Try to avoid swaying the torso from side to side.
• Alternate which elbow you lower first, doing as many reps as you can for 30 seconds.

Jump Squats

The classic squat is a great exercise for toning the derriere, and when you add a jump, the move becomes more effective.  Jumping also increases your heart rate to burn even more calories — bonus!

• Begin in an athletic stance with feet shoulder-width apart and arms bent with hands at chest level.  Bend knees and come into a full squat.
• Jump up as explosively as you can, reaching for the ceiling.
• When you land, lower back into the squat position to complete one rep.
• Do as many jumps as you can for 30 seconds.

Elbow Plank With Hip Dips

• From an elbow plank position, slowly rotate the spine to lower your right hip to just above the floor.  Come back to elbow plank.
• Now lower the left hip toward the floor.
• This counts as one rep.
• Do as many reps as you can for 30 seconds.

Give your backside some attention and try our four-week squat challenge!  Learn the specifics on each style of squat included in this circuit, then put your knowledge to practise with this plan.  Be sure to hang it on your fridge to inspire you to work it!

You want strong, defined abs, and you're willing to work hard for them, right?  Then get on the floor and bust out this 100-rep crunch workout.  This circuit involves five crunch variations.  Do 10 reps of each and repeat this 50-rep circuit twice.

Or for an even more intense ab-burn, do each exercise for 20 reps and do all 100-reps at once.  If this is more than your abs can handle, just do five reps of each and repeat that 25-rep circuit four times, taking breaks when you need to.

Crunchy Frog

• Begin sitting, balanced just behind your sits bones, and rock back slightly to lift your feet off the floor;  gently pull your knees to your chest.
• Exhale, pull your navel to your spine, and lean back slightly as you open your arms to the sides and straighten your legs.
• Inhale and return to the starting position to complete one rep.
• Perform 10 reps.

V Crunch

• Lie on your back, and lift your legs and arms up so they are extended toward the ceiling.  Lift your upper back off the floor, reaching your hands toward your feet.
• Lower your legs toward the floor while reaching your arms overhead, keeping your shoulders off the mat and your lower back pressed into the mat.
• Repeat the crunch motion to complete one rep.
• Do 10 reps.

Bicycle Crunches

• Lie flat on the floor with your lower back pressed to the ground (pull your abs down to also target your deep abs).  Interlace your fingers, and put your hands behind your head.
• Bring your knees in toward your chest, and lift your shoulder blades off the ground.
• Straighten your right leg out to about a 45-degree angle to the ground while turning your upper body to the left, bringing your right elbow toward the left knee.  Make sure your rib cage is moving and not just your elbows.
• Now switch sides, and do the same motion on the other side to complete one rep (and to create the "pedaling" motion).
• Do a total of 10 reps.

Reverse Crunch

• Lying on your back, lift your legs in the air with your knees bent.  Place your hands on the floor beside you.
• Without momentum, use your lower abs to slowly curl the hips off the floor and into your chest.  Slowly lower them back to the starting position.
• This counts as one rep.
• Perform 10 reps.

Butterfly Crunch

• Lie on your back with your knees open and the soles of your feet together (in a butterfly position).  Lengthen your arms overhead so they are resting on the floor.
• Exhale and bring your hands and knees toward each other, performing a full-body crunch.  Your shoulder blades should be off the mat as you perform a small reverse crunch, lifting your pelvis a bit off the mat.  Hold this position for a moment, and really feel your abs squeezing.
• Slowly lower your arms and feet back to starting position to complete one rep.
• Do 10 reps.
• You're halfway there!  Repeat this 50-rep circuit once more.  Then reward your efforts with the stretch below.

Cobra Pose

After working your abs so thoroughly, roll over onto your belly and do this stretch — it'll feel sooo good.

• Lie on your stomach and bring your legs together so your knees are touching.  Extend your arms straight out in front of you.
• As you lift your head up off the ground, slowly walk your hands in, keeping your hips and thighs on the ground, but gently arching your lower back.  Walk them in as far as you want, keeping your elbows slightly bent.  If your back is really flexible, you can begin to straighten your arms.
• Actively roll your shoulders back and down away from your ears, elongating your neck.  Keep looking in front of you, or if you want more of a stretch, drop your head back between your shoulder blades.
• Stay here, opening through the chest, making sure to relax all your muscles (don't clench your butt).  After five deep breaths, slowly lower your chest back to the ground.  Lay your arms next to the sides of your body and bring one cheek to the ground.

We can always count on the gorgeous Karlie Kloss for fitness inspiration.  On Dec. 2, the 24-year-old beauty posted a powerful boxing video on Instagram to help us get our weekend in check — we'll be hitting the gym.  When we say powerful, we mean we can literally feel her intensity through the screen.

Did anyone else duck as Karlie's fast and ferocious fist comes out at the screen?

Karlie has been working out at the New York City-based Dogpound for a while, documenting her fierce workouts alongside the gym's cofounder Kirk Meyers.  Her #FitnessFriday posts are the kick in the butt we need to get us moving to the gym!  Check out this killer 30-minute cardio-boxing and core workout to try at home.