Affiliations: [a] Aristotle University of Thessaloniki, Greece
Note: [] Address for correspondence: Athanasios Zakas, Department of
Physical Education and Sports Science, Coaching and Sports Performance
Laboratory, Aristotle University of Thessaloniki, Thessaloniki 540 06, Greece.
Tel.: +32310 992211; Fax: +32310 992211; E-mail: azakas@phed.auth.gr
Abstract: While athletes routinely perform warm-up and stretching exercise, it
has been suggested that prolonged stretching, immediately prior to an activity,
might affect negatively the force production. Fifteen professional soccer
players participated in the study to examine whether a routine duration of
acute static stretching may account for losses in isokinetic peak torque
production. All participants performed two static stretching protocols on the
rectus femoris muscle tendon unit (MTU), at different training sessions, with a
week interval. The first stretching protocol was performed four times for 15 s
(4 × 15 s), and the second 32 times for 15 s (32
× 15 s). Range of motion (ROM) was determined during
knee flexion, with a pendular Myrin flexometer. The peak torque of the dominant
leg extensors was measured on a Cybex Norm dynamometer at 60, 90, 150, 210 and
270°/s angular velocities. The 2
× 2 analysis of variance showed that peak torque
remained unchanged, following the total static stretching for 60 s in all
angular velocities, while it decreased in all angular velocities, following a
total static stretching for 8 minutes (p<0.001). The
findings suggest that an acute static stretching exercise of short duration, as
performed by soccer players, during warming up procedures, does not produce
decreases in peak torque, compared to multiple stretches of an 8 minute long
duration.
Keywords: Flexibility, stretching duration, range of motion, isokinetic peak torque, strength loss
