The hip flexors are a group of muscles in the front of the hip that act to lift the knee and bring the thigh towards the abdomen. The major muscles making up the hip flexors that we will focus on are the iliacus and the psoas, or the iliopsoas and the rectus femoris. The rectus femoris  is a “two joint muscle” because it crosses both the hip and knee joints. As a group, the hip flexors have attachments on the lumbar spine, the pelvis, and the femur. In addition to their major function of flexing the hip, their attachment on the spine makes them an important part of the core muscles and spinal stabilizers.
Apply the above concept to your hips. When you sit, your hips are in a "flexed" position. Therefore, the muscles that flex your hips are in a shortened state. You probably spend at least a third of your day sitting down. Think about how much time those hip flexor muscles stay shortened. A lot. Over time, they become tighter and tighter until you look like the old man in the picture. So unless you want to look like that, perform the stretches shown below. 

The first step that needs to be taken is to determine if the tightness is due to a true lack of flexibility (perform the Thomas test above) or if it is because of weakness in the muscle itself. Once that is determined you need to focus on reducing the tension felt in the hip flexor and improving core control/stability so that the issue does not return. As with any condition, the root cause must be found (the root cause is not often at the site of pain) in order to get long lasting relief. This is why so many people unfortunately have to deal with this issue for several months or even years…..because the root cause was never found and they were just given generic information to “open up the hips” or “just stretch more”. Below are some common exercises I like to give to patient’s to start out with to help alleviate this condition. (Please keep in mind that every individual patient has different needs but these exercises tend to work in MOST cases.) The first hip flexor exercise involves actually strengthening the hip flexor while focusing on a neutral spine for core stability.
Do standard/oblique crunches. Lie down on a mat and position both arms behind your head without locking the hands. Bend your knees so that your feet are flat on the ground. Pushing the small of your back into the ground, slowly roll your shoulders off the ground only a couple of inches (not to a full sitting position). Don't use your momentum to help you up; use slow, regulated movements. Repeat 3 x 20.
Most folks work a 9 to 5 position but if you’re not in the corporate world yet then odds are you’re a student with classes scattered throughout the day and it takes up the vast portion of your free time. That being said, you’re likely going to have to work out in the morning or the evening in order to fit in your session amidst the hectic commitments in your everyday life. Here are a few things to consider in regards to each time period:
Consult your physician and follow all safety instructions before beginning any exercise program or using any supplement or meal replacement product, especially if you have any unique medical conditions or needs. The contents on our website are for informational purposes only, and are not intended to diagnose any medical condition, replace the advice of a healthcare professional, or provide any medical advice, diagnosis, or treatment.
Now, if you are somebody that is more of the “do-it-yourself” type, check out our self-paced online course, the Nerd Fitness Academy. The Academy has 20+ workouts for both bodyweight or weight training, a benchmark test to determine your starting workout, HD demonstrations of every movement, boss battles so you know when you to level up your routine, meal plans, a questing system, and supportive community.
Don’t get us wrong—cardio is important for keeping your body fat down and keeping your heart health in check. (Bonus points if you run or bike, since outdoor exercise is linked to better energy and improved mental health.) But when it comes to building muscle, hitting the treadmill won't help you much. “Every component of exercise, minus cardio, can help with muscle hypertrophy,” which is the scientific term for muscle building, says Michelle Lovitt, an exercise physiologist and trainer in Los Angeles. “Cardio tends to burn calories and puts your body in a deficit, which is great for leaning out, but not building mass.”
How to do it: Lie on your back with both feet planted firmly against the flat base of a Bosu ball, knees bent. Stabilize your body. If you’re feeling a bit wobbly, your arms can hover on either side of you in case you fall in one direction. If you feel balanced, raise your arms straight up above your chest, hands clasped to challenge and work your stability. Drive your hips toward the ceiling, then lower and repeat.  
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