# The Effect of Regular Physical Activity on Muscle and Adipose Tissue in Premenopausal Women
## 4 Discussion  
The essential outcome of the assessment of total body mass in the monitored women was the finding that women with the lowest volume of leisure-time PA (T1) had the least favorable body composition. Although the occurrence of overweight was lower and obesity was higher in these women than the rates reported by the WHO [2], the values were within the expected ranges of values reported in the Czech Republic. Eurostat data showed the prevalence of overweight women at 30.1% and obesity at 18.3% [32]; similar values were  
Figure 1: Mean values of segmental body mass and body fat distribution in the monitored women. (**A**) Distribution of BM and BF in upper limbs, (**B**) Distribution of BM and BF in lower limbs, (**C**) Distribution of BM and BF in the trunk. \({}^{\rm{ns}}\) not significant, \({}^{\star}p<0.05\), \({}^{\star\star}p<0.01\), \({}^{\star\star\star}p<0.001\). also reported by the Czech Statistical Office [33]. The BMI values determined in women with a medium (T2) and a high volume of PA (T3) were considerably lower. The considerably lower body fat ratio found in women with a medium (T2) and a high volume of PA (T3) when compared with the values of the women with the lowest volume of PA (T1) corresponded to the differences in their weight status. The differences found in body fat were not only significant, but also considerably higher than the stated error of measurement in body fat assessment using the bone densitometer [34]. The lower BF ratio in T2 and T3 women was also related to the higher fat-free mass ratio, which was suggested by the weight differences. In general, lower body fat values and higher fat-free mass values reduce the risk of cardiac metabolic diseases [35; 36]. Based on our results, we can conclude that the aforesaid also applies to the women in the study with a medium (T2) and a high volume of PA (T3). This is important especially in view of the fact that BF increases and FFM decreases in women as they age [37]. Distinct changes in women's body composition occur in relation to menopause [3]. The results of a study based on the data from the Study of Women's Health Across the Nation (SWAN) showed that there is a considerable increase in BF, accompanied by a decrease in FFM about 2 years prior to the final menstrual period (FMP) and these changes slow down about 1.5 years after the FMP. After this period, the aforementioned changes (BF increase and FFM decrease) occur evenly [3]. To confirm the total weight status based on BMI, we also compared the percentage ratios of body mass and body fat weight in the whole-body and segmental analyses between the groups of monitored women. The ratio of total weight and body fat weight was preserved even in the ratio in the limb segments (upper and lower). Differences in the ratios of total weight and body fat weight in the trunk were higher than in the limbs between T1 and T2, and between T1 and T3. The only difference in the ratio in the trunk and in the limbs between T2 and T3 was found in the body fat weight. The differences in the visceral fat values, expressed as an area in this study (VFA), were caused by the different values for the amount of fat in the trunk. The significantly higher VFA values in women with the lowest volume of PA (T1) indicated an increased risk of overweight, obesity, cardiovascular and metabolic complications, as shown by studies confirming links between visceral fat, cardiovascular complications, obesity, and type 2 diabetes [38; 39; 40]. The risk of visceral fat is determined by its higher metabolic activity than the activity of subcutaneous fat [41]. Overweight and obesity usually act as demotivational factors for regular physical activity. The evidence for this lies in the increasing number of people who are overweight or obese [2]. Muscles not exposed to load have a clear tendency to atrophy, the muscle cross-section decreases, and sarcopenia starts to develop, which can be assessed using the appendicular index, based on the DXA measurement.