This study was conducted to investigate the effectiveness of ankle muscle strengthening program of 8 weeks on the underwater dolphin kick performance in young swimmers. This study was a randomized controlled trial. Swimmers was divided in two groups; eccentric ankle muscle-strengthening exercises and control group. The outcome measures were strength of plantar flexors, dorsal flexors, internal rotators, external rotators and 5-meter underwater dolphin kick time.

There is limited information on the effectiveness of ankle joint muscles in respect to the knee, hip, back and upper extremity muscles creating the propulsive forces for the feet to transfer the moment force towards water. Therefore, it is aimed to observe the effects of eccentric ankle muscle-strengthening exercises given by means of elastic bands on the Underwater Dolphin Kick performance of young swimmers.

Inclusion Criteria:

• Having swimming training at least three times per week for the last year and using the proper UDK technique, which was assessed by the swimming trainer of the participants.

Exclusion Criteria:

• having any lower extremity injury or low back pain.