Leg Swings are a dynamic stretch swimmers can do to improve hip mobility, as well using their core to drive home the kick
Ankle Circles are essential for breast strokers as this stretch can help develop the ankle flexibility needed for a strong kick
Hamstring cramps occur often in swimming, stretching them before hopping in the water can cut back on these cramps by almost 70%. Drinking water helps too!
Arm Circles are very basic but can warm up your shoulder muscles before hopping in the water. Shoulder pains are the number 1 most complained about injury in swimming so it is important to keep those muscles fresh and loose.
The Butterfly stretch is surprisingly not for the stroke butterfly. This stretch will increase hip mobility and flexibility which is key for the kick when rotating in Freestyle and Backstroke
Cross-body Shoulder Stretch or Arm Bar is extremely beneficial to your shoulder muscles and shoulder flexibility, this will work on the interior muscles used on fly and breaststroke.