Even if you regularly exercise, the act of sitting all day in the same position can build tension in a number of areas of the body.

Yoga instructor Jill Miller knows the problems poor posture can cause, and luckily she has two easy stretches that can be performed after work to counter the day's tension.

Hip flexor stretch

 

Miller explains in one of her videos for Oprah's #OWNSHOW that hip tension is a major cause of sleeplessness for office workers.

She has a two-minute stretch that aims to get the tension out of your hips, and Miller says over time it should also lead to better sleep.

She demonstrates the stretch using a wall and a block, which you can substitute with a thick book, as props.

"Lay on your back and then plant your left foot against the wall while your pelvis is supported on the block," says Miller.

"Then fold your right knee and draw it in towards your chest."

She says it might look like your folded knee is doing all the fancy work, but in fact all the work is happening across the front of your straight leg.

This exercise is giving the hip flexor (or psoas) muscle a deep stretch.

"That deep hip flexor gets short and tight the longer you sit," says Miller.

"That psoas, being connected to the lower back bones, its attachments don't just stop there. It's also connected to your diaphragm, your chief breathing muscle," Miller explains.

"So if your hip flexors get short and tight, guess what that impacts? Your ability to breathe deeply. If you can't breathe deeply, you can't relax."

Miller says to do the stretch just for one minute on each side.

Shoulder stretch

 

Another great stretch suggested by Miller is for your shoulders, which get tight from a day on a computer.

The stretch corrects your posture (which tends to get worse as the day goes on) and the only prop you need is a strap – a belt works perfectly for this.

Start by holding the strap in both hands with palms faced down, and arms spread wide enough to feel the stretch.

Then, reach your hands up and over your head, until they're at a 30 degree angle above your shoulders.

"You should feel stretch across the very front of your chest; all the way through the biceps, across the elbow, and into your forearms," says Miller.

She says it's important not to cheat by sticking your ribs out, because then you won't feel the stretch.

"Keep your rips on top of your pelvis so you don't miss out on the wonderful sensation ," says Miller.

Another way to perform the same exercise is to use a doorway, says Miller, and do the stretch for 30 seconds or three to five breaths.

"You'll be able to unwind all that tension from that hunch," says Miller.

"We slouch over all day; this is how you'll be able to bring yourself back to life."