Squat (SJ) and Counter Movement Jump (CMJ) Tests

Before commending the jump tests, participants completed a general warm-up procedure that included 5 min of running, stretching of lower limbs muscles, and 2 min of jumping exercises. SJ and CMJ heights were assessed using the Optojump photoelectronic cells (Optojump Next, Microgate, Italy) (Glatthorn et al., 2011). Jump heights were determined from the recorded contact and flight time of jumps with a sampling rate of 1 kHz. The SJ began at a 90° knee angle; avoiding downward movement, participants performed a vertical jump by pushing their body upward with the legs. The CMJ began from an upright position, whereby participants made a rapid downward movement to a knee angle of approximately 90°, arms akimbo and simultaneously beginning to push-off, after being instructed to jump as fast and high as possible. Both tests were performed without an arm swing by fixing hands at the level of the pelvis and with knees and ankles extended at take-off and landing. The highest of four jumps was recorded for each test, and a 30 s recovery was given between each jump.