Impact of Elastic Band Resistance Training on Female Football Performance: A Pilot Study

Primary outcomes

1. Knee extension and flexion isometric strength

   Time frame: At the beginning and end of the study (Week 1 and Week 6)

   Maximal isometric knee extension and flexion force will be measured using a handheld dynamometer (DynaMo Plus, VALD Performance, Brisbane, Queensland, Australia). For the knee extension assessment, participants will be in a seated position, whereas during the knee flexion evaluation, the participants will be in a prone position. To generate their maximal torque, the dynamometer chain length will be adjusted so that their knee angle will be at ∼60° and ∼30°, for the knee extension and flexion, respectively. Participants will then apply a maximal isometric effort, maintaining it for 5s, without any subsidiary body movements.

2. Vertical jump

   Time frame: At the beginning and end of the study (Week 1 and Week 6)

   Jump height was evaluated using an optical measurement system (OptoJump, Microgate, Bolzano, Italy). The players will perform the countermovement jump, where they will begin from an upright position; a rapid downward movement to a knee angle of ∼90°, immediately transitioning to propel themselves upwards into the air.

3. Change of direction sprint

   Time frame: At the beginning and end of the study (Week 1 and Week 6)

   The Modified T-Test will be implemented to assess change of direction sprint. This evaluation has within itself directional changes such as forward sprinting, left and right-side shuffling, and backpedaling. Photocells (WhittyGate, Microgate, Bolzano, Italy) will be used for a more precise time count.