Studies have shown that physical activity reduces the chances of getting non-communicable diseases, but a recent study by the University of the Witwatersrand Sport and Health Research Group (WiSH) and Discovery medical aid has found that physical activity also has a positive effect on Covid-19 diagnosis.

The study called Small Steps, Strong Shield, which was recently published in the British Journal of Sports Medicine, found that regular exercise can lessen chances of dying from Covid-19 by up to 42%.

WiSH's Prof Jon Patricios, Vitality wellness clinician Deepak Patel and a team of Discovery actuaries led by Lizelle Steenkamp analysed physical activity data linked to Vitality members infected with Covid-19.

The work was made easier as Vitality members use the app to record their activity levels — using smartwatches and other devices — on the app.

The team analysed data from 65,361 adult patients with a Covid-19 diagnosis from March 19 2020 to June 30 2021.

The individuals were grouped by activity level: low (< 60 mins a week), Moderate (60-149 mins a week) and high activity (> 150 mins a week).

According to the journal: “The association of physical activity levels and the risk of adverse outcomes was analysed using modified Poisson regression [linear graph].

“We accounted for demographics and comorbidities including conditions known to influence Covid-19 outcomes, as well as patient complexity as measured by the Johns Hopkins Adjusted Clinical Group system [which quantifies morbidity by grouping individuals based on age and gender and all medical diagnoses over the period].

“The regression approach was further validated with a Bayesian network model [which measures probabilistic variables and dependencies] built off a directed acyclic graph [spider diagram].”

The findings were that physical activity was associated with fewer hospitalisations.

Those engaged in the highest levels of physical activity before the pandemic experienced:

• 34% lower risk of hospital admission,
• 41% lower risk of ICU admission,
• 45% lower risk of requiring ventilation and
• 42% lower risk of death from Covid-19.

Patients engaged in moderate activity had:

• 13% lower risk of hospital admission,
• 20% lower risk of ICU admission,
• 27% lower risk of ventilation and
• 21% lower risk of death compared to the low-activity group.

Vitality CEO Dinesh Govender, at a media briefing on Thursday, said at the time lockdown restrictions were put in place to limit the pressure on healthcare facilities.

“But the unintended consequence of limiting movement has been the significant decrease in exercise levels seen during the pandemic, with subsequent implications for individual wellbeing.”

He said the month after hard lockdown showed a 49% drop in members logging their physical activity points when compared to 2019.

Govender said the concern was that the inactivity “may become entrenched for many around the world”.

“It is clear, then, that we need to enhance our efforts to promote regular exercise as an adjunct to vaccination and other preventive measures, especially for those at high risk, and educate about the benefits of physical activity in the context of communicable diseases.”

The science behind the experiment shows that exercise benefits the immune system by mobilising white blood cells — the healing cells — which fight off infection, and reduce inflammation. This enhances the body’s ability to recognise harmful pathogens like Covid-19.

According to the World Health Organisation, physical activity reduces non-communicable diseases like diabetes, hypertension, coronary heart disease, depression, stroke, and colon and breast cancer. 

“We are likely to see future waves and pandemics in our lifetime. Now we can take lessons learnt during this pandemic to find innovative approaches to allow citizens to safely engage in physical activity, while still taking public health measures to secure the health and wellbeing of those around us,” Govender said.

TimesLIVE