Performance of a jump squat involve

Performance of a jump squat involved subjects completing a maximal-effort CMJ while holding a rigid bar across
their shoulders. Subjects held a 0.4-kg carbon fiber pole for
the 0% 1RM jump squat, whereas for all other intensities,
subjects held a 20-kg barbell loaded with the appropriate
weight plates. Participants were instructed to keep constant
downward pressure on the bar throughout the jump and
were encouraged to move the resistance as fast as possible
to achieve maximal power output with each trial (2). Performance of the SJ also involved subjects holding the 0.4-kg
carbon fiber pole across their shoulders. Subjects were
instructed to lower into a back squat position with a knee
angle of approximately 90- of flexion and hold this position
for 3 s. When instructed, subjects then jumped as rapidly
as possible in an attempt to maximize power output while
performing no previous countermovement. Trials with any
observable countermovement, determined as any degree of
unloading in the vertical ground reaction force–time curve
immediately before the jump, were repeated. For all jump