Flexible inner thighs are good for general mobility and will help for running, walking, swimming, biking etc. The purpose of the muscles in your inner thighs, called adductors, is to pull your legs together. The adductors are engaged but squeezing your legs together.
This is one of the easiest inner thigh and groin stretches you can do and it’s perfect to do in bed just before going to sleep at night.
Lay on your back in bed and put the soles of your feet together while bending your legs. Gently open up your legs by pressing your knees out to the sides. You can adjust the stretch to fit your agility level by positioning your feet close or far away from you. It’s easier with your feet further away. If needed, you can place your hands on your thighs to add a bit of extra pressure. Hold the position for the desired amount of time and then repeat.