This study explored the impacts of LTPA on cardiorespiratory fitness, co-morbidity level, adiposity indices and QoL of midlife adults. The data in this study have shown that the participants in the two groups were similar in age, WC and BMI. However, participants in the LTPA group had significantly lower co-morbidity score and RHR, and better VO2max and QoL than those in non-LTPA group. In addition, the data show that LTPA status was associated with heart disease and hypertension severity. Furthermore, hypertension co-morbidity was lower in the LTPA group than in the non-LTPA group.
The finding of impact of LTPA on co-morbidity in this study is similar to the finding in a previous study that LTPA is inversely associated with all-cause mortality in men.32 Warburton et al32 reported that a linear relationship exist between PA and health status, a surrogate index of co-morbidity, such that an increase in PA and fitness will lead to additional improvements in health status. Indeed, beginning a moderate sports activity is associated with lower rates of death from all-cause and from coronary heart diseases among middle-aged men and older adults.33 According to,34 regular LTPA is associated with improved health perception. Similarly, LTPA is associated with a longer life expectancy in individuals with cardio-metabolic multi-morbidity.35 These benefits from PA behavior are regardless of the type or source.33
The finding on impact of LTPA on diabetes-related co-morbidity in this study is in contrast to the findings in previous similar studies.36,37 The difference in the findings between the current study and the previous ones could be attributed to the design differences, in that the previous studies followed up a cohort of participants who engaged in LTPA. In the current study, it is not possible to ascertain that any other diabetes-predisposing factors, such as diet and genetic disposition status, are the same or evenly distributed between the LTPA and non-LTPA groups. The implications of these factors not being similar between the two groups, especially if those factors confer an advantage on non-LTPA group, is that the possible gain by the LTPA group due to their PA participation could be balanced out by the positive factors in non-LTPA group.
In line with a finding in this study, Yu et al38 reported no difference in WC and BMI across low-moderate-vigorous categories of LTPA. Indeed,39 report that change in LTPA is unrelated to subsequent weight change. In addition, contrary to the findings in this study, previous studies report that LTPA reduces the risk of obesity.40,41 This risk is reduced by 5 percentage points with LTPA participation, and by 11 points if LTPA is combined with some work-related PA.41 The difference in findings between the current and previous studies could be attributed to the difference in study designs.
The finding that hypertension-related co-morbidity was lower in LTPA group than non-LTPA group is similar to the finding that LTPA is associated with the risk of hypertension among middle-aged men.42 Similarly, the finding that hypertension occurrence is associated with LTPA status is explained in light of the finding that absence of moderate-vigorous LTPA is associated with an increased risk of hypertension.43 Indeed, Werneck et al44 have reported that engaging in sufficient level of LTPA could attenuate, but not eliminate, the negative influence of obesity on high BP. These findings therefore imply that LTPA could be used to reduce hypertension incidence and severity in midlife men and thereby reduced the risk of cardiac diseases. Indeed, aerobic dance, a form LTPA, has been reported to reduce BP, number of antihypertensive drugs and BP control rate in individual with hypertension.45 Thus, increase the knowledge of individuals with hypertension about benefits of PA for their condition will increase their participation in it.46
In line with findings of association between LTPA and cardiac disease in this study, prior studies have reported that LTPA is inversely associated with risk of CVD,40, 47,48 especially among sedentary people.47 Indeed, when leisure time is sedentary, the risk for cardiometabolic diseases increases.49 LTPA has been reported to reduce carotid artery stiffness.50 However, this benefit is decreased in those above the age of 65 years, and those with a history of CVD.48 This association could be mediated by the impacts of LTPA on individual traditional cardiovascular risk factors.51 These impacts may be attributed to the reduced cardiovascular mortality in moderate- and high-intensity LTPA adherents,47,52 and the largest reduction is observed with approximately 300 minutes of walking per week,52 largest intensity of LTPA and after 10 years of LTPA behaviour.48 This amount of LTPA/week translates to approximately 150 to 300 min/wk of long-term vigorous-intensity LTPA or 300 to 600 min/wk of long-term moderate-intensity LTPA.53
The finding from this study that there was a higher VO2max in participants that engaged in LTPA than those that did not, is similar to those in previous studies.54–56 In fact, a dose-related increase in VO2max from sedentary men, through active men, to endurance-trained men has been observed.57 In addition, similar to a finding in this study, Yu et al38 reported that firefighters who engaged in LTPA had lower resting heart rate than those who didn’t. These findings imply that midlife adult men who engage in LTPA have a higher cardio-respiratory fitness than their counterparts who don’t.
The finding of impact of LTPA on QoL of participants in this study is similar to that of a previous study.58 However, in contrast to the finding in this study, Tessier et al59 reported that the long-term association between LTPA and QoL changes is limited and has little clinical significance, especially for men and for the physical health dimension of QoL. This contrast could be attributed to the different designs employed in the two studies, in which LTPA was self-reported through a questionnaire in Tessier’s et al, study, as against identification of LTPA adherents against their controls in the current study. The recall bias and over-reporting limitations of self-report assessment may be responsible for the contrasting findings between the current study and Tessier’s et al. In addition, Wendel-Vos et al60 report that cross-sectional associations are mainly found for physical health dimension of QoL, whereas longitudinal associations are predominantly observed for the mental health dimension. However, a study on effect of aerobic dance, a form of LTPA, on QoL showed larger improvement in physical health, psychological health and environment domains of health-related QoL among participants who engaged in 12-week aerobic aerobic exercise than those who didn’t.61 Generally, PA increased QoL of the physically active men more than inactive men.62 Nonetheless, Stahl et al63 suggest that a social environment is also important for physically active individuals to have good QoL.
The findings that LTPA did not have impact on mental health, and that LTPA status was not associated with mental health severity contradict the finding in a previous study that LTPA had weak positive association with positive mental health.64–66 The difference in the findings between the two studies could be attributed to self-report mode of determining LTPA in the previous study, which could introduce bias of over- or under-reporting. In addition, the non-LTPA group in the current study may be largely individuals with positive mental health who do not have to benefit significantly from any mental-health-improving intervention. According to Appelqvist-Schimdlechner et al67 LTPA and physical fitness may improve mental health, but LTPA, rather than physical fitness, seems to be more essential for positive mental health.67 Thus, PA strategies aimed at improving mental health for men should provide opportunities, particularly, for LTPA involving social interactions.64 In addition, low-to-moderate LTPA has been reported to lower the risks for symptoms of depression, burnout, and high stress levels while only moderate-intensity LTPA lowers the risk of anxiety.68,69 In addition, high-intensity LTPA may increase the risk of incident depression.68 Thus, LTPA intervention for mental health has to be symptom-based.
The strength of this study lies in th actual determination of LTPA behaviour status as opposed to use of self-report. The approach adopted in this study is expected to remove group assignment error that characterises the use of self-report due to under- or over-reporting. However, the use of self-report in determining co-morbidity score and disease status in this study may limit interpretation of the finding in this study. Nonetheless, standardized nature of the instrument employed to assess comorbidity is expected to reduce the inherent error associated with the use of such self-report.
In conclusion, regular LTPA improves cardiovascular health, physical work capacity and QoL in mid-life men. Regular LTPA behaviour is recommended for cardiovascular health promotion, and improved physical work capacity and life satisfaction in midlife men.