Menopause is responsible for significant changes in the body, which may contribute to increased fat mass 1 and reduced lean body mass 2 ; this can be potentiated by low levels of physical activity (PA). 3 The prevalence of physical inactivity (<150 min of moderate to vigorous PA weekly) 4 increases with age, reaching 30% in postmenopausal women, 5 a factor which can lead to reduced muscle mass and strength, impaired locomotion and balance, 6 possibly increasing the number of falls and successively decreasing the quality of life thereby leading to dependence to perform daily activities.

The American College of Sports Medicine (ACSM) 4 emphasizes the importance of the accumulation of at least 30 min/day of moderate–vigorous physical activity (MVPA) in order to maintain health. Corroborating with the recommendations of the ACSM, studies have shown an inverse relationship between PA levels and health and, consequently, with mortality in the general population. 7 Additionally, Buonani et al. 3 reported that postmenopausal women who demonstrated higher values in minutes of moderate–vigorous PA had lower levels of body fat and higher levels of lean body mass compared to women who demonstrated less than 150 min/week.

Various techniques have been used to attempt to quantify the total level of PA performed. In recent years, accelerometry has been receiving increased attention, as it is an objective method, which allows the estimation of the relationship between physical activity and health, and identifies findings which are not perceptible when using subjective measures such as questionnaires. 8 In addition, accelerometers allow the total PA performed during exercise, work, leisure and the different activities of daily living as well as the intensity of these actions, to be obtained.

It is known that intense PA tends to decrease with increasing age and that this situation is particularly pronounced in postmenopausal women. 5 According to the observations of Mota et al. 9 the total MVPA at weekends (32 min/week) presented a reduction of 28% compared to weekdays (44 min/week) in men and women aged 63–80 years, participants of a physical activity program. Moreover, people aged over 50 years who spend a lot of time in sedentary physical activity showed high risk factor for mortality independent of MVPA. 10

Knowing that MVPA is a strong predictor of cardiometabolic health 4 ; that increased levels of PA are directly related to lower amount of body fat, 3 thus contributing to a reduction in several chronic diseases 4 and that sedentary behavior may increase the risk of mortality, 10 it is of great importance to understand the behavior of weekly physical activity levels in obese postmenopausal women. Furthermore, we should emphasize that women enter menopause after 40 years old, however, this event may be early or late, 11 so if we take as a reference the life expectancy of the female population which is 78.3 years, 12 it is expected that women are postmenopausal for about 1/3 of their life. Thus, strategies that seek to minimize the consequences of this period are of great importance for improving the quality of life of these women. Therefore, this study aimed to analyze possible differences between the levels of PA practiced during the week and at the weekend in obese postmenopausal women.

The ACSM 4 emphasizes the importance to health of the accumulation of 150 min/week of MVPA. In the present study sample, it can be observed that 63.2% (n = 74) of the participants met the recommendation of the ACSM whilst 36.8% (n = 43) failed to meet the recommendation. When comparing these two groups, it can be seen that the participants who accumulated over 150 min/week of MVPA presented lower age [58.1 (7.9) versus 61.7 (11.6) years, p = 0.013], lower body mass index [BMI = 27 (6.3) versus BMI = 28.7 (7.0) kg/m2, p = 0.206] and lower levels of body fat percentage [42.4 (8.6) versus 45.0 (9.7), p = 0.152], however, no statistically significant difference in relation to body composition.

When comparing the level of physical activity of the women who met the ACSM recommendations with those who did not, it was observed that during the days of the week, the insufficiently active women had higher values of light physical activity [7076.2 (1438.1) versus 6863.8 (1417.2) min/wk; p = 0.029] and lower levels of moderate physical activity [62.2 (49.0) versus 237.6 (135.4) min/wk; p < 0.001].

At the weekend, the insufficiently active women again presented higher values of light physical activity [2863.0 (27.9) versus 2822.5 (55.7) min/wk; p < 0.001] and lower moderate physical activity [17.0 (27.9) versus 57.5 (55.7) min/wk; p < 0.001].

Table 1 presents the sample characteristics in median and interquartile range values. The participants in this study presented BMIs of around 31.1 kg/m2 and an average of 42.8% body fat.

In Table 2 the median, interquartile range and confidence interval (95% CI) comparing the levels of PA on weekdays with those at the weekend are presented. It can be seen that the women in the study showed a significant increase in PA-light (p < 0.001) and a significant reduction in PA-moderate, PA-vigorous, and MVPA (p < 0.001) at the weekend compared to the weekdays.

When verifying the difference between MVPA practiced at weekends compared to weekdays, we noted an average reduction of 44.0% (p < 0.001).

This was a cross-sectional study which observed that postmenopausal women had increased levels of PA-light and reduced levels of PA-moderate, PA-vigorous and MVPA at weekends compared to weekdays.

Increasing MVPA contributes to greater energy expenditure per minute compared to PA-light, however, reduced MVPA, when associated with poor eating habits, can result in a positive energy balance and contribute to a framework for obesity. 17 The significant increase in body fat after menopause, especially in the central region, 1 leads to an increased risk of cardiovascular disease and metabolic syndrome 18 ; one in two women eventually die as a result of these diseases. 19 Thus, the practice of PA is fundamental for this population, since there is an inverse relationship between the level of PA and the risk of type 2 diabetes, hypertension and cardiovascular diseases. 20

In a seven year longitudinal study of Canadians, Curtis et al. 21 observed greater involvement in PA programs of women from 45 to 54 years and men aged 65 years and over which could be explained by the resocialization process in both groups and greater awareness among women of the benefits of PA for weight loss and prevention of osteoporosis. Despite increasing awareness regarding the importance of PA on health, the results presented here show that levels of moderate intensity PA are still quite low compared to PA-light, both on weekdays (34.8 × 1404.1 min/day), and at the weekend (20 × 1420 min/day), respectively.

Anjos et al. 22 investigated the patterns of PA in 1689 individuals of different age groups and both sexes, through 24-h recall, and observed that most of the subjects met the 30 min of PA recommended by the ACSM, 4 however the men accumulated greater moderate to vigorous activity during leisure activities and the women during domestic activities. Although activities of daily living (ADLs), promote increased energy expenditure, the intensity of these activities is generally mild (<3 METs or <2690 counts) and is not sufficient to promote improved fitness or reduce the risk of chronic diseases and mortality associated with insufficient physical activity. 23 It is worth reiterating that in this study the measurement of PA was performed objectively using a triaxial accelerometer, thus avoiding possible errors of measurement from self-reporting, since the perception of light, moderate or vigorous PA in this population may be compromised. 24 This protocol provides a reliable measurement of PA practice and strengthens once again the importance of the findings presented here.

When comparing MVPA on weekdays compared to the weekend, it was noted that the women evaluated in this study accumulated an average of 35.7 min/day on weekdays and 20.0 min/day at the weekend, i.e., a reduction of 44.0%, which is higher than that observed in a study by Mota et al., 9 in which 24 volunteers were evaluated, 18 female and six male, aged between 63 and 80 years where an average of 44 min/day on weekdays and 32 min/day at the weekend was observed (28% reduction).

The findings of this study suggest that, in general, the study population should reduce the time spent in PA-light and increase MVPA, both on weekdays and at the weekends. Accumulating activity in short sessions during the day could be an interesting strategy, especially for individuals who feel they do not have enough time to perform continuous physical activity over an extended period of time, moreover, this practice allows for greater tolerance to the stimulus for sedentary individuals who have lower levels of physical fitness. 25

Despite the importance of the results found here, some limitations should be mentioned. Firstly, the cross-sectional design does not allow consideration of the effect of time on the PA of these women, secondly only three days a week were considered for analysis, thirdly, the time spent in different intensities of PA should be considered approximate since there is no reference value for triaxial accelerometers for postmenopausal women, fourthly, no analysis was performed according to age and finally, the tri-axial accelerometer does not provide a measurement of sedentary behavior of the participants. Furthermore the fact that the sample was comprised of obese women may be a confounding factor to be considered in assessing levels of practice of PA.

In summary, postmenopausal women have reduced levels of PA-moderate, PA-vigorous and MVPA at weekends compared to weekdays and increased PA-light. Thus, strategies aimed at contributing to an increase in moderate–vigorous physical activity in women in this stage of life, particularly at the weekends, should be encouraged by public health agencies in order to reduce the chances of a possible future cardiovascular event.

The authors declare that there are not conflicts of interests.