The benefits of engaging in physical activity have been widely established, with studies showing that physically active individuals are likely to incur reduced healthcare-associated costs, and minimal decline in functional impairment in comparison with their inactive counterparts (Plow, Allen, & Resnik, 2011).
However, several factors can negatively affect physical activity among different individuals depending on their age and the condition they are suffering from, thus depriving them of the perceived benefits of participating in physical exercise.
Depression is one of the prevalent psychological disorders that affect the capacity of physical activity among different individuals, but few studies have been conducted along this line, with several of the studies that have been done is on the effects of physical activity on depression.
Moreover, considering that depression is related to complications such as coronary artery disease and myocardial infarction, its capability to influence physical activity making matters more complex (Jerstad, Boutelle, Ness, Stice, 2010; Plow et al., 2011). This review seeks to evaluate critically various studies that have been conducted on the effects of depression on physical activity.
Literature Review
Some studies have been conducted to establish the relationship between depression and physical activity. Accordingly, Jerstad et al. (2010) sought to examine the bidirectional association between depression and physical activity by investigating whether future intensification of depression can be reduced through physical activity. Moreover, the study investigated whether depression reduces future physical activity levels.
The method employed in this particular study involved a longitudinal assessment on an annual basis involving 496 girls (out of which 56% were recruited) of an average age of 13 years, with a six-year follow up made to assess the outcome measures. The participants filled questionnaires as well as participating in other procedures such as structured interviews that enabled measures to be taken on an annual basis.
Additionally, research assistants were charged with taking height and weight readings during the follow-up. The girls participated in three to four physical activities for more than ten times in the final year of the study. The baseline depression was about 13%, with the measures being taken six times throughout the study (Jerstad et al., 2010).
The findings of the study show that future increases in depression incidences among the participants of the study would be significantly decreased by physical activity. Moreover, the study showed that depression, and the symptoms associated with it, significantly reduces future physical activity among the participants (Jerstad et al., 2010).
Here, Jerstad et al. (2010) note that the capability of girls to participate in exercise and sporting events could be attributable to other factors such as self-esteem, which usually accompanies depression. As a result, this study is useful because it shows the bidirectional relationship between depression and physical activity, in that depression affects physical activity and vice versa.
Moreover, the study provides a framework under which future studies can be based on, and shows the need for considering the bidirectional association between depression and physical activities when designing interventions that aim to reduce depression, or increase physical activity, especially among teenage girls.
Furthermore, the study shows the need for parents and health professionals to discourage inactive life and advocating for physical exercise, especially in families that have a history of depression cases. Additionally, the study has several other strengths, such as a 6-year follow-up, a large sample, and the measuring of several elements of physical activity, which enhance its credibility.
However, the study is limited because it involves a selected population (teenage girls), which limits the generalisability of the findings to other age groups and adolescent boys.
Further, the study is limited because of issues involving the validity of physical activity measures because only regular exercises were taken, with no assessment of metabolic equivalents of the tasks being carried out. Last, the study involved a recruitment rate of 56%, which is moderate but may raise issues about bias (Jerstad et al., 2010).
Similarly, Egger et al. (2008) investigate whether depression and anxiety symptoms affect the physical exercise capacity as well as the body mass index (BMI) in patients undergoing cardiac rehabilitation. The design measure used involved an outpatient intervention programme involving 114 (92 men and 22 women) cardiac patients of a mean age of 60 ±11, with coronary artery disease.
The method utilised in this study involved measuring the BMI, exercise capacity, and symptoms related to depression and anxiety both before and after the rehabilitation process. The study involved 5-6 hours of exercise weekly for 4-12 weeks. The symptoms of depression and anxiety were measured by using the hospital Anxiety and Depression Scale (HADS).
The findings of the study show that there was a significant increase in exercise capacity levels among the participants as well as reduced anxiety and depression as the programme continued, but no changes were observed in BMI levels.
Moreover, the study found that when the covariates (HADS measure for depression [HADS] and HADS measure for anxiety [HADS-A]) were controlled, there was a corresponding change in exercise capacity. However, depression and anxiety changes were not related to BMI (Egger et al., 2008).
As such, the study is useful in the current review because it shows that depression affects the change in exercise capacity in a negative manner among individuals engaging in cardiac rehabilitation.
Additionally, for the patients undergoing cardiac rehabilitation, the study is useful because it shows the need for health professionals to mitigate depression because it may alleviate any benefits received from cardiac rehabilitation by negatively affecting the capability of patients to exercise effectively.
However, the study is limited because it involves a small target population (cardiac patients), and thus, the findings may not be generalisable to include the other persons who are outside this group. Moreover, most of the patients were in the old age, which limits generalisability of the study to young people. Furthermore, issues of bias may arise because far more men than women were involved in the study.
Likewise, Plow et al. (2011) examined the barriers associated with health and have an impact on physical activity among the elderly. The study involved 490 community-dwelling persons aged 65 years and above with Rhode Island (RI) Medicaid cover. Most of the participants of this study were non-Hispanic whites (69.8%), with female participants being more (79.6%) compared to their male counterparts (20.4%).
The factors related to physical activity were determined by the using of ordinal regression. The study findings show that factors such as depression, social isolation, and hopelessness decreased the participation in physical activities among the participants (Plow et al., 2011).
Additionally, the study found that the problems of depression, social isolation, and hopelessness were more common among the elderly persons who had a low income compared to those having a higher income (Plow et al., 2011).
This study is relevant to the current review because it shows that depression is one factor that affects the elderly individuals in terms of their capability to engage in physical exercise. Furthermore, few studies have been conducted on the effects of depression on the physical activity levels among the vulnerable groups such as the elderly persons who have low income.
Furthermore, the study has other strengths such as a relatively large sample size, and a cross-sectional study method, which enhances the credibility and applicability. However, several issues and measures that were taken to limit the applicability of the study findings. First, the physical activity measures were obtained by using self-reports, which may lead to inaccurate information being given.
Second, the sample used in the study included far more women compared to the male counterparts, which may lead to issues of gender bias. Third, the study involved the elderly persons with Medicaid coverage, and therefore, the results may not be generalisable to young people. Moreover, most of the participants involved were non-Hispanic whites, thus limiting the applicability of the findings to other racial populations (Plow et al., 2011).
Conclusion
There is a bidirectional association between depression and physical activity, that is, physical activity reduces depression and its symptoms, while depression impairs physical activity levels among different individuals.
Considering that the benefits of engaging in physical activity are well documented by the relevant research that has been conducted, there is the need for health professionals to diagnose and treat depression to increase the physical activity of patients.
Additionally, it is essential for health professionals to consider the vulnerable groups such as the elderly and adolescent girls who are disproportionately affected by depression in comparison with other populations, which results in reduced physical activity.
As such, intervention measures should be designed with an aim of mitigating depression and encouraging physical activity, thus enhancing the general wellbeing of patients as well as cutting healthcare-associated costs.
References
Egger, E., et al. (2008). Depression and anxiety symptoms affect change in exercise capacity during cardiac rehabilitation. European Journal of Cardiovascular Prevention & Rehabilitation, 15, 704-708.
Jerstad, S. J., Boutelle, K. N., Ness, K. K., Stice E. (2010). Prospective reciprocal relations between physical activity and depression in female adolescents. Journal of Consulting and clinical Psychology, 78 (2), 268-272.
Plow, M. A., Allen, S. M., Resnik, L. (2011). Correlates of physical activity among low income older adults. Journal of Applied Gerontology, 30 (5), 629-642.