Stretching after running helps to decrease injury and, if done correctly, will strengthen your muscles and improve your flexibility and range of motion. Stretching should not be painful, so listen to your body and go as deep as you can without experiencing any pain. Rather focus on slight discomfort. Hold each stretch for three to five breaths.
Low lunge
Lower your left knee to the floor, sliding the right foot back until you feel a nice stretch in the left-hip flexors and thigh (quad). Square off your hips (left hip forward, draw right hip back so hipline is parallel to the wall in front of you) and make sure your right knee is above your heel. Be mindful that the knee does not overshoot the toe. As you inhale, engage your core, and lift your chest away from the thigh, then repeat on the other side. This stretch is good for your hip flexors, quads, and glutes.
Half Split
From your low lunge, exhale and straighten the right leg. Keep the foot flexed to stretch into the calf, rotate your right outer hip back (this will isolate the hamstring) and make sure your left hip sits directly over your left knee. Repeat on the other side. This stretch is good for your hamstrings, calves, and glutes. Using yoga blocks will help maintain a straight spine. Once again, keep the stretch in your glutes and hamstrings rather than the lower back.
Half Shoe Lace
Bend your right leg under your left, cross at the knees, place your left knee on top of your right knee while the outer edges of your foot touch the floor. If you feel like you are not getting enough of a stretch here, gently fold forward with a straight spine to increase the stretch. Then repeat on the other side. This stretch is good for ITB and glutes. Your IT band is a thick bunch of fibres that runs from the outside of your hips to the outside of your thigh and knee down to the top of your shinbone. If your IT band gets too tight, it can lead to swelling and pain around your knee.
Figure of Four
Seated on the floor (or on a chair if you prefer), take the leg of the side you want to stretch and cross it over (near the ankle) the other leg just above the knee. This will look like a figure 4. Keep your back straight and extend your chest forward towards your shin, pivoting at your hips, then repeat on the other side. This stretch is good for hip mobility and glutes.
Pyramid
Step one foot halfway back at a 45° angle. Point your front foot forward as you keep your feet on separate tracks (i.e. there is a slither of light between your heels). Breathe in as you reach forward with a long straight spine and breathe out as you fold forward and rest your hands on either side of your front foot. Use yoga blocks to keep your spine straight without rounding to keep the stretch into the glutes and hamstrings on the front leg. In your back leg, you should feel a stretch into your calves. Then repeat on the other side. This stretch is good for strengthening the legs, especially the hamstrings, and improving core strength.
Half Squat
Step your feet a comfortable width apart, then bend into the one leg, keeping the knee and second toe aligned, and press the opposite heal into the earth (toes facing up to the sky). Press your hands or upper arms into your inner thighs to give a deeper stretch into the adductors. Repeat on both sides, then give yourself a high five for an awesome session.