Essay: Health Benefits Of Walking Below Recommended Levels Reviewed.

Topic: Determining the Health Benefits of Walking below recommended levels of exercise: Effectiveness Reviewed

Physical activity and sedentary lifestyle are closely associated when it comes to developing conditions such as obesity, low metabolic rate, high blood pressure, and several other diseases commonly seen in sedentary individuals. Therefore, it is highly recommended that people must participate in some form of physical activity to keep the health risks at bay. As a pre-designed mobile creature, human are supposed to move. Any form of movement is welcoming for the skeletal muscles of the human body. Walking, running, weight lifting, and several other forms of physical activity, carried out on a regular basis reduces the chances of developing diseases at a significant level. Lack of time is one of the reasons why people fail to find time to participate in physical activity. Health promotion programs require to be designed in a way that it will promote the importance of exercise, reaping maximum amount of benefits without disrupting the busy schedule.   

A critical appraisal has been carried out on the work of a school of researcher who has tried to determine the health benefits of walking at or below recommended levels, in an unsupervised environment, in order to reduce the risk of cardiovascular diseases among sedentary adults. The effectiveness of walking below the recommended levels was determined with the help of the randomized controlled study. There are still several limitations to this study, which needs to be addressed as part of future trends in order to derive a conclusive theory based on the results.  

Rationale of the Study

It has been especially in countries with high income, the busy life and the resultant lack of time results into people not participating in active physical activity. Physical inactivity or a sedentary lifestyle is an identified determinant of causing non-communicable diseases, such as diabetes, cardiovascular diseases (Bauman et al., 2012). Public health promoting interventions can only be designed once there is a better understanding of the cause of inactivity among the masses. Research has been carried out for some time now in determining the association of health with moderate-to-vigorous intensity physical activity (MVPA) (Wilmot et al., 2012). Evidences have been obtained where it has been stated that engaging in physical activity regularly lowers the risk of cardiovascular diseases, obesity, high blood pressure. However, it is yet to be identified the type of exercise that needs to be carried out and the dosage is yet to be suggested to obtain maximum benefit from it (Vanhees et al., 2012).  

Some, to lead a healthy lifestyle perform several known and practiced physical activities. Among them, walking is considered an effective and a simple form of physical activity, which does not require any prior training or equipment. The health benefits of brisk or moderate walking are plenty however, this field has not been studied previously, therefore, there is still plenty of room left to determine the health benefits of walking.

The study, ‘Randomised controlled trial of home-based walking programmes at and below current recommended levels of exercise in sedentary adults’ by Tully et al. (2007), has been critically evaluated in the following sections.  

The given paper deals with the attribute that a certain dosage level can be determined in respect to walking as part of the home-based programme aimed at reducing cardiovascular risk. The rationale has been formed based on the theory that a minimum dosage level can be reached in respect to unsupervised walking programme among sedentary adults where the recommended target of performing physical activity cannot be reached due to lack of time.

The objective of the given study has been to analyze the effects that unsupervised walking programmes has in reducing cardiovascular risk and in increasing the functional capacity of an individual, by performing the exercise at a level lower than the recommended levels.

The methodology as followed by Tully et al. (2007) has been critically evaluated in the following sections.

Randomly selected participants were grouped into 3 days a week and 5 days a week, 30 min brisk walking groups. Pedometers were used to count the number of steps taken. The control group served the purpose of comparing the results obtained from the study. The study was aimed at measuring the difference in blood pressure level, cholesterol level, body mass index and functional capacity, before and after the study was performed, that is, in 12 weeks’ time.

Objective of the Study

The study design was based on the Randomized Controlled Trial (RCT) where the participants were divided into three groups, were subjected to 30 min of brisk walking for 3 days a week (first group, n=44) and for 4 days a week (second group, n=42). The numbers of steps were measured using a pedometer. The results were analyzed based of paired t-test for determining the analysis of change within the groups. The extent of change between the groups was compared using analysis of variance (ANOVA) and Gabriel’s post hoc test.

The location selected for carrying out the study was the Northern Ireland Civil Service (NICS). The period chosen for the study was March ’03 to July ’03, a total period of 12 weeks.  

A total of 106 participants were selected. They were divided into three groups. The first group comprised of 44 participants; the second group comprised of 42 participants and the control group consisted of 20 participants.

The participants of the study were all employees of the NICS and they were aged between 40 years and older, belonging to both the sexes. They were sent an email to invite them as a participant for the study. They were later explained through phone calls as well as through mails regarding the details of the study. Their consent was solicited for. The approval for conducting the study was given by the Queen’s University of Belfast research ethics committee. The participants who had attended were asked to fill a questionnaire and their blood pressure was measured. The participants who were selected based on the following criteria:

• Blood pressure level lower than 140/90
• No history of cardiac, pulmonary or musculoskeletal diseases
• No usage of drugs that may affect lipid metabolism
• Self report of sedentary lifestyle where the participant has not participated in a session of exercise of moderate intensity resulting in increased respiratory and heart rate, over a period of six months  

The selected participants were asked to come after a week to be divided into groups and to measure the baseline. They were allocated to groups based on random numbers that were generated by the computer and revealed only after the baseline measurement had been completed.

The exposure and outcome in this study share do not share a non-causal association. In a non-causal association involves variables that are independent of each other. However, in this study, both the outcome as well as the exposure is closely related to each other.  

The results are likely to be affected by selection bias. The most common source of selection bias that affected the results is selection through self. In this study, the subjects for the intervention, though selected randomly, an error remained which led to the error while computing the BMI. The 3-day group had more men than women as compared to the 5- day group. The whole program was unsupervised which resulted into self determined walking pace and self-reporting.

Methods

The results are likely to be affected by the confounding factors. There are several limitations of the study, which act as confounding factors. The response from the interventions have been very low therefore the sample size considered was not enough to yield conclusive results. The results for the measurement of cholesterol levels in the subjects could not be obtained. The walking was self-reported as well as the pace of walking was self determined. This again limits the theory claimed by the study as non-conclusive. Unsupervised walking might not be quite effective given the subjects have no way to identify if there has been a change in pace over the experimentation period of 30 min. Therefore, the shuttle test review might not be accurate where there are possibilities where the motivation of the participant has directly influenced their performance level. The sex imbalance in the intervention groups also played the role of confounding factor in the study. The 3-day group included more men than women as compared to 5-day group. Therefore, it was difficult to determine the significant difference in BMI between these two groups. The familiarity is another confounding factor that has affected the results when considering the increase in functional capacity of the subjects. Due to lack of proper contact between the test subjects, it was difficult to organize a practice test. This led to the control group to have covered a slightly greater distance in comparison to the two test groups.    

The results are likely to be affected by chance variation. In chance variation, there is a scope of error from typically three sources, sampling, measurement and biological variation at individual level. The results for lipid and BMI measurement was affected due to the biological variation as 3 day a week group had more men than women as compared to 5 day a week group. There is evidence of sampling error because the walking was self reported as well as the walking pace was self determined. Due to lack of contact, the practice test on the intervention group was not carried out. This has resulted with the control group walking extra distance than the intervention groups. The chance variation could have only been avoided if the size of the study had been increased.

exposure and Outcome Relationship Analyzed

There is evidence of causal association between the exposure and the outcome. In this study, unsupervised walking is a variable and reduction in cardiovascular risk is the second variable. Both the variables are directly affecting each other.

Interventions of the Study

A temporal relationship exists between the exposure and the outcome. Evidences show that the information related to the outcome was collected after the information of exposure.

A strong relationship exists between the exposure and the outcome. The exposure deals with the idea of reducing the cardiovascular risks that increases due to inactivity. It is closely related to the outcome where the unsupervised walking programme in association with a pedometer has led to reduction in blood pressure, which shows that a strong relationship exists between the exposure and the outcome.  `

A dose-response relationship exists between the exposure and the outcome. Evidences state that there was a reduction in the blood pressure level for the subjects in the 3-day group (outcome). Exposure referred to the reduction of cardiovascular risks. So even with a lesser amount of physical activity, there is a reduction in blood pressure, which shows that a dose-response relationship exists.

No, the results are not consistent within the study. The results are varied due to the existence of chance variation, selection biasness and several confounding factors. Care had to be taken in order to avoid the results to be affected by these determinants.

The findings in the study are in accord to the various evidences based on the different measured outcomes of the study. The findings in the study are consistent with other evidences that are either similar or more powerful than the design of the given study. The results that have been obtained from the study, in accordance to other evidences, are as follows:

Changes in the blood pressure were observed in both the 3 days a week group as well as the 5 days a week group because of unsupervised walking for 30 min for 12 weeks. It was established that the extent of reduction in blood pressure was found to be clinically significant in reducing the risks of death due to cardiovascular related diseases. Research carried out by Kato et al. (2014) has established the concept that consumption of lemon along with walking is responsible in reducing the blood pressure level. The results that were obtained showed a significant negative correlation to the systolic blood pressure. Lee et al. (2010) had also carried out a similar study where they had reviewed walking intervention in controlling the blood pressure level. They had carried out a systematic review based on 27 randomized control trials. They concluded that experiments comprising of such interventions must be of a large scale so that the results determined are more conclusive. The study revealed the effectiveness of walking in lowering the blood pressure, which may vary from moderate to high intensity walking. Borjesson et al. (2016) has also conducted a similar study where they had determined the benefits of exercise and physical activity that has in reducing the blood pressure in individuals with hypertension. It was a narrative review based on 27 randomized controlled trials. Hanson and Jones (2015), has tried to establish the theory by carrying out a meta analysis of walking groups being responsible for controlling the blood pressure level. Wanderley et al. (2010) have also conducted similar studies on older women where the effects of moderate as well as intense walking program on the blood pressure, body composition and functionality was determined.

Study Design

 Changes in lipid level also established the benefits that walking has on the health of the people. A significant decrease in the LDL cholesterol was observed however, the same could not be said for HDL cholesterol or triglycerides. The changes as seen in the study are hardly of any clinical significance. It shows that further study needs to be carried out with strictly chosen interventions qualifying the requirements, where the experiment is not affected by sample size or biological variations related to genetic differences. Irrespective of the lack of significant data, several evidences exist where the lipid level gets affected on carrying out physical activity. Duvivier et al. (2013) had carried out the study involving minimal intensity of physical activity, which can be standing or walking, for a longer duration, resulting into improvement of insulin action and plasma lipids. They have established the theory that if the energy expenditure is kept constant. It can compensate against the negative effects that inactivity has on the lipid and insulin levels. Mann, Beedie & Jimenez (2014) carried out a review to establish a similar theory where the differential effects were determined that aerobic exercise; resistance training as well as combined exercise has on the cholesterol level.  Since elevated cholesterol levels has a direct correlation with heart diseases, therefore, they have tried to review based on the findings of 13 articles to establish an optimal dosage of exercise that will lead to effectively lowering of cholesterol levels.

Evidences also exist to support the idea where pedometer based walking has proved to be effective in reaping health benefits. Baker et al. (2008) had studied the effects that pedometer based walking on the health of the people. It was a study similar to that of the given article, which is being reviewed. The study also carried out 12 weeks long randomized controlled trials in a Scottish community. The results obtained were helpful in promoting a pedometer based walking programme for people who do not meet the recommended levels of physical activity. Murtagh et al. (2014) has also worked on determining the effects of walking on reducing the risks of cardiovascular diseases by studying previously carried out 32 randomized controlled trials. Similar works were carried out by Qiu et al. (2014) and Miyazaki et al. (2013), each one studying the effects of walking with the help of pedometer, in order to reduce the risks of cardiovascular diseases. Evidences also reveal the reduction in body mass index when subjects participate in walking (Hirsch et al., 2014).   

The results are plausible in every aspect, in respect to biological mechanism as the proposed theory has real benefits to the subjects. The results obtained apply to subjects directly. Evidences also support the idea that unsupervised walking below the recommended level can help in reducing the blood pressure and increase functionality. A slight variation may occur due to the genetic difference among the interventions otherwise the results are quite plausible.  

The findings are externally valid, that is they are generalizable. The findings of the study can be used as a representation of the entire population from where the sample was taken. In this study, an Irish community was considered. The study population was derived from NICE’s employees. The subjects are part of the Irish community therefore the results can be applied to the source population (Irish population) from which the study population (NICE’s employees) were derived. The study result can also be applied to other relevant populations. However, this cannot be entirely validated as the researchers had identified it as one of their major limitations that they need to consider a bigger sample size to determine conclusive data.

Conclusion

A study was conducted to determine the effectiveness of a home-based walking programme, at or below the recommended levels on sedentary adults by Tully et al. (2007). The study was effective in identifying home-based walking programme below the recommended levels for sedentary adults in reducing the rate of cardiovascular risk in them. The results obtained from the study might prove to be a source of encouragement for people who lack time to participate in physical activity, to exercise at a lower target of 3 days a week to achieve benefits from walking. Further studies requires to be conducted to identify the long term effects that unsupervised walking associated with low level of exercise, has on reducing the chances of cardiovascular risks. This study also aims at determining the relevance it has in respect to the public policy and government initiatives, which has been aimed at increasing the levels of physical activity amongst the UK population. This study is suggestive of an innovative measure in encouraging adults to take active participation in physical activity. The data obtained from this study may help in developing strategies for health promotion.     

References:

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