Changes in Isokinetic Strength and Power of Lower Limbs in Young Female Soccer Players in Training Microcycle of Competitive Season. A Case Study

Muscle fatigue affects player’s performance. The aim of the present study was to investigate changes in isokinetic torque and power of lower limbs, in young female soccer players, in training microcycle of competitive season. The sample consisted of 11 female soccer players U17 (age: 16.3±0.8 years, height: 166.4±6.4 cm, body weight: 64.7±11.7 kg) who competed in the 3rd national division championship. The participants were assessed isokinetically (concentric assessment of knee extensors/flexors muscles in three different angular speeds: 60°/s, 180°/s, 300°/s) and in counter movement jump, 72 hours before and 24, 48 and 72 hours after the match. Significant differences were revealed (F=5,681, p=0.038) in isokinetic assessment. Extensors significantly differed at 60°/s between initial measurements and 48 hours after the match (p=0.008), as well as 48 to 72 hours postmatch (p=0.017). Flexors significantly differed between the measurements at 24 to 48 hours at 300°/s (p=0.025). Analysis of the CMJ data showed that both CMJ with and without arm swing had no significant differences in performance between all four measurements. Knee muscles isokinetic assessment is an indicator of muscle fatigue, following a match. Planning of training microcycle should be designed according to the specific needs and characteristics of female soccer players.