A foot sprain usually occurs when the foot twists, causing a tear of the ligaments in the foot. The length of your recovery time depends heavily on the type of sprain you've suffered. A simple grade I tear is only a stretching of the ligaments; a grade II sprain involves the actual tearing of the ligaments; and a grade III tear results in ligaments that are completely torn. Your doctor will likely suggest that you rest your foot to allow time for the ligaments to heal before you resume playing a sport.
Immediately after suffering a sprain, it's best to rest your foot. Continuing to play on a sprained foot could lead to the aggravation of the injury, lengthening your healing time. The best course of action immediately following a sprain is the RICE method -- rest, ice, compression and elevation. The four components work together to relieve swelling and pain. It's usually also fine to take an over-the-counter pain medication to relieve swelling and pain in the first 24 to 48 hours after your injury.
You'll need time for your foot to heal properly to avoid future pain. The American Academy of Orthopaedic Surgeons breaks the healing process into three phases. To complete the phases and begin regular activity will require a minimum three weeks, depending on the severity of your sprain. During the first week, you should rest and protect your foot to avoid aggravation and reduce swelling. During the second week, you may be able to begin light exercises for range of motion and flexibility. In the third week, it's usually fine to gradually return to using your foot as normal without special maneuverability. As your foot becomes more comfortable, you can then begin training exercises for your sport before you return to full mobility -- usually within six weeks.
After the first week of rest and with the approval of your doctor, you should be able to begin rehabilitative exercises to restore strength and flexibility to your foot. To start, try sitting with your feet straight in front of you. Use your big toe to write out your name or the alphabet. When you feel strong enough, loop a towel around your feet while sitting in the same position and gently pull your feet toward your torso. As you strengthen your foot, you can begin standing exercises, such as bracing yourself against a wall while you roll onto your toes, then back to your heels.
After three to six weeks, you'll likely be able to return to playing sports, but you'll need to be cautious about caring for and protecting your foot. Stretch your feet before each game to warm the ligaments for better flexibility. Before playing sports that require quick stops, starts and changing of directions, choose a supportive shoe that has stiff sides to protect your foot from rolling and spraining again. If your foot hurts when playing, take a break and apply the RICE treatment again.