Since the coronavirus disease 2019 (COVID-19) pandemic began, physical mobility outside one’s own home has been repeatedly and severely restricted, in most parts of the world, in an attempt to contain the spread of the virus. A new preprint research paper published on the medRxiv* server describes the changes that have taken place in moderate-to-vigorous intensity aerobic physical activity (MVPA) and muscle-strengthening activity (MSA).
According to conventional standards, an inactive adult has less than 30 minutes of moderate physical activity per week. Optimal physical activity is deemed to be consistent with 150 minutes or more/week of MVPA (any activity that boosts the heart rate and body temperature) and MSA (strength/resistance training) for two or more days a week. Both are known to reduce both ill-health and the risk of premature death, in isolation or together.
The current study focuses on MVPA and MSA before and after the start of the UK COVID-19 outbreak, including the first lockdown. The aim was to characterize the type and degree of change in both parameters, as well as to identify the associated risk factors for change in either the up or down direction.
The researchers analyzed sociodemographic and living conditions, such as sex, race, education to or after age 16, employment, lay-off, income, and age. The presence of comorbidities or adverse living conditions, and any habits or addictions, that had a potential impact on either MVPA or MSA were also evaluated. The time of enrolment in the study, and when the individual began to be affected by COVID-19.
In the study, there were over 2,600 adults, with roughly equal numbers of males and females. Over 90% were white, and over two-thirds had completed high school or higher.
The researchers found that relative to MVPA, about a third of adults said they had kept their level of activity the same, a third said they had become more active, and a third reported being less active. When it came to MSA, almost two-thirds of people said they continued at the same level of MSA, while about a fifth reduced or increased the number of days they did MSA.
Only about 15% of adults met the WHO recommendations for both MVPA and MSA before the pandemic.
Overall, the same proportion of adults continued to have no MVPA or MSA after COVID-19.
Risk factors for changes in MVPA+MSA
The scientists found that the odds of meeting WHO guidelines for both MVPA and MSA were lower in older people (over 65 years), those with lower household income, obesity, being isolated, and poor mental health. Those who had completed high school, at least, and/or met WHO MVPA/MSA standards before the pandemic began were more likely to meet the recommendations for both during the pandemic, compared to not meeting either.
The odds of meeting MVPA standards after the pandemic began were higher if the individual had a limiting physical condition, was isolated, or had poor mental health, or met WHO standards of either MVPA or both MVPA and MSA. The odds for meeting MSA standards only were reduced for people aged 35-64 years, for obese individuals, but increased with education beyond high school or if both MVPA/MSA recommendations were already being met pre-COVID-19.
Changes in MVPA
MVPA was likely to remain stable in older white people who had completed high school at least, and had space to exercise. This could be due to their more regimented schedule and lower level of exercise.
People with poor mental health, living in total isolation, and with limiting physical conditions were at increased risk of reducing their MVPA from the levels they had before the pandemic. White people who had a job during the pandemic, and were totally isolated, tended not to increase their MVPA. In contrast, an increase was associated with having a high school education or living with children.
Changes in MSA
Having a too-high body mass index (BMI), and having a job during the lockdown, was associated with an increased chance of reducing MSA, while the chances of increasing MSA were lower when the people were older or had worse mental health. It is noteworthy that mental health deterioration is associated with reduced MVPA from pre-COVID-19 levels, or low MVPA, but not MSA. More research will show if the mental ill-health is predictive of, or the result of, low exercise levels, but when an individual begins to exercise more, it is likely to result in better mental health as well.
What are the implications?
The researchers identified risk groups, such as those at higher risk of not having recommended MVPA and MSA, to be explicitly targeted. Those who were already exercising as recommended when the pandemic started were most likely to continue doing the same. Thus, those who were not exercising well before the lockdown should be specially targeted to become more active.
Overall, more than seven in ten adults in the UK either continued or increased their level of MVPA could be due, at least in part, to the flexibility of the UK government towards outdoor activity even during the lockdown, unlike many other countries. MSA was maintained at the same level, probably because it was already at low levels before the pandemic and because little equipment is required for most MSA exercises. This is supported by the fact that those who were totally isolated were associated with changes in MVPA alone.
“Aerobic and strength training were differently impacted during the first UK lockdown, with poorer outcomes associated with older age, lower education, and higher body mass index.” Thus, interventions should be tailored to enhance the level of MVPA and MSA among the more sedentary individuals, as well as those with risk factors like low household income, older age, or obesity.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
Herbec, A. et al. (2021). Correlates of and changes in aerobic physical activity and strength training before and after the onset of COVID-19 pandemic in the UK. Findings from the HEBECO study. medRxiv preprint. doi: https://doi.org/10.1101/2021.01.16.21249925. https://www.medrxiv.org/content/10.1101/2021.01.16.21249925v1