Introduction:
Nowadays more women are trying to shape their figure properly. Changes in the menstrual cycle can affect the dynamic muscle parameters of women.

Aim:
The aim of the study was to assess muscle strength in various phases of the menstrual cycle in young women

Material and methods:
The study involved 23 women aged 20–22. All the women had menstrual periods (27 ± 3.16 days). The strength measurement was made by means of Microfet2 (Hoggan Health Industries, USA), which was fixed permanently to the floor. The test was performed on the knee flexors at the angle of 10° and 90° and hip flexors in the neutral position and the glenohumeral joint (shoulder) extensors at the flexion of 90°. The lever arm was marked with the use of anthropometric points. The test was performed three times in each phase of the menstrual cycle; in the early follicular phase (2nd–5th day), the ovular (12th–15th day) and in the luteal phase (16th–28th day).

Results and discussion:
No statistically significant differences in the muscle torque values during the menstrual cycle were confirmed in the test. The P value of the arm extensors is 0.33, for hip flexors is 0.79 and hamstring muscle with a bent knee joint in 90° and 10° is 0.311, 0.567, respectively. No statistically significant differences between the particular cycles phases were confirmed either.

Conclusions:
In the menstrual cycle in young women, there are no significant differences in muscle strength during the individual phases.