**1. Introduction**

The prevalence of an insufficient level of physical activity (PA) in pregnan<sup>t</sup> women has been demonstrated in studies using representative samples in different countries [1–4]. Despite the well-documented benefits of involvement in PA in this period of life [5–7], it is emphasized that pregnancy continues to be one of the causes of a substantial reduction in PA [8–10].

Over the past two decades, most studies which have focused on these problems have estimated that most pregnan<sup>t</sup> women do not participate in recommended PA. Clark and Gross [11] demonstrated that 39% of women who reported participating in some forms of weekly exercise before pregnancy did not report pursuing any similar activities during pregnancy. Similarly, Fell et al. [12], in a comparative study of women's levels of PA during early pregnancy and during the year before pregnancy, observed that most women reduced their PA levels during the first 20 weeks of pregnancy compared with their level of activity during the year prior to pregnancy.

According to the data presented by Evenson et al. [1], only 15.8% of pregnan<sup>t</sup> women in the USA reported being active, in accordance with the recommendations. In a cohort study conducted in Brazil, Domingues and Barros [2] estimated that only 4.3% of women were active during the whole pregnancy. Furthermore, [13] found that only 14.6% of women in mid-pregnancy in Norway were involved in the exercise ≥3 times a week, >20 min at moderate intensity. According to Santo et al. [4], merely 9% of 1584 pregnan<sup>t</sup> women met the American College of Obstetrics and Gynecology ACOG guidelines. Furthermore, nearly half of the women reported PA < 1 day/week during the third trimester. Similarly, Haakstad et al. [3] found that only 11% of pregnan<sup>t</sup> women followed ACOG guidelines regarding PA.

The problem of inadequate levels of PA is particularly important in the context of the relationship of PA to the quality of life (QoL) of pregnan<sup>t</sup> women. Recently published studies have provided important information on changes that occur in health-related QOL (HRQoL), both during pregnancy and [14] in the perinatal period [15]. A problem that remains to be discussed is the explanation of the relationships between PA and the quality of life of pregnan<sup>t</sup> women [16–20]. No unambiguous findings have been published to date in this area, since interpretation is difficult due to the use of different measurement tools, both for the evaluation of PA during pregnancy and the quality of life. For example, some researchers have used the results obtained with the Global Physical Activity Questionnaire (GPAQ) and 36-Item Short-Form Health Survey (SF-36) [20], while others have used the Pregnancy Physical Activity Questionnaire (PPAQ) and the abridged World Health Organization Quality of Life (WHOQoL-Bref) [16,18]. In addition to these tools, other questionnaires have been popular and are frequently used in the assessment of the quality of life, with an extensive review and discussion of their use being presented by Mogos et al. [21].

Despite many analyses, the problem of correlations between PA and the quality of life of pregnan<sup>t</sup> women remains to be solved and still raises many questions that need to be addressed. To the best of our knowledge, the few studies that have used the PPAQ and WHOOoL-Bref tools [16,18] have failed to analyze the Polish population. Therefore, the aim of this study was to obtain information about the relationships between PA and QoL among pregnan<sup>t</sup> women in Poland. The QoL was evaluated by a reliable questionnaire used in surveys of pregnan<sup>t</sup> women (WHOQoL-Bref) [16,22–24], whereas PA was measured using the increasingly popular PPAQ questionnaire [25–34]. Furthermore, we hope that the choice of the above measurement tools will allow for replication of the study results and comparison with future research conducted on a wider scale.
