New study published in BJSM: How is regular physical activity associated with blood sugar control and complications in people living with type 2 diabetes? 

A new South African study published in the British Journal of Sports Medicine (BJSM), including almost 18,500 Discovery Health Medical Scheme members living with type 2 diabetes, finds higher levels of physical activity associated with better blood sugar control, delayed insulin initiation and lower risk of cardiovascular complications.  

Authors 

Discovery Health's Claudia Pastellides and Lizelle Steenkamp with Discovery Vitality's Dr Deepak Patel, and Dr Mosima Mabunda; Mike Greyling (Data Management and Statistical Analysis); and University of the Witwatersrand's Dr Reyna Daya; Prof Zaheer Bayat and Prof Jon Patricios.  

Quick overview 

Regular physical activity is an important part of managing type 2 diabetes (T2D). But how strongly is physical activity associated with blood sugar control and the risk of diabetes-related complications in a real-world setting? A South African study published in the British Journal of Sports Medicine (BJSM) in November 2026 (World Diabetes Month), analysed anonymised health and physical activity data from 18,485 adults living with type 2 diabetes who were Discovery Health Medical Scheme members and participants in Vitality Active Rewards. The research combines Discovery Health and Discovery Vitality expertise with independent clinical and academic collaborators affiliated with the University of the Witwatersrand. 

The study covered the period 1 January 2012 to 30 June 2024. Physical activity was recorded through sources including wearable devices, gym attendance and participation in organised fitness events. Participants' physical activity was classified as 'no recorded activity', 'low activity' (1 to 59 minutes a week), 'medium activity' (60 to 149 minutes a week), or 'high activity' (150 minutes or more of moderate-to-vigorous physical activity a week).  

Researchers found that higher levels of recorded physical activity were associated with better blood sugar control and delayed insulin initiation, as well as more favourable outcomes for certain cardiovascular complications. The study also provides insights into the association between sustained physical activity and engagement in Vitality Active Rewards, and wearable-device use. 

Among participants followed over three years, those using a linked wearable device recorded higher and more sustained activity levels than those were not. And, after activating Vitality Active Rewards, participants recorded higher levels of physical activity, with the proportion reaching 150 minutes or more a week, more than doubling.  

Physical activity is an important part of managing type 2 diabetes, but sustaining it can be challenging 

The global prevalence of type 2 diabetes (T2D) has doubled from 7% in 1990 to 14% in 2022, with more than 800 million adults worldwide living with diabetes by 2024. Lifestyle changes, including greater physical activity, weight management and a healthy diet, alongside appropriate medication, are central to managing this condition. 

Previous research has shown that physical activity can improve blood sugar control and other cardiovascular risk factors. However, maintaining physical activity over the long term remains challenging. Much of the existing evidence also comes from populations in the northern hemisphere, leaving relatively little evidence from African and other populations. 

This study therefore set out to explore the relationship between recorded physical activity and T2D outcomes in a large South African cohort, using real-world activity data rather than relying solely on participants to recall and self-report their exercise. 

What did this research analyse? 

The study included 18,485 adults aged 30 to 75 who were registered for the Discovery Health Medical Scheme (DHMS) Chronic Illness Benefit for T2D (during the period from 1 January 2012 to 30 June 2024), had joined Vitality before their diabetes benefit registration and had activated Vitality Active Rewards. The study relied on anonymised data on these individuals.  

  • Vitality is a voluntary, science-based, behavioral-change and wellness programme in South Africa (created by Discovery) that rewards members for improving their physical health, eating well, and tracking their well-being.  
  • Vitality Active Rewards (VAR) is a feature of the Vitality programme that uses personalised in-app activity weekly goals and incentives to encourage regular exercise, with activity recorded through sources such as wearable devices, gym visits and organised fitness events. For those who achieve the weekly goals, the programme awards "Discovery Miles" which can be monetised or used as a currency to purchase a range of goods and services. 

The study covered the period from 1 January 2012 to 30 June 2024, with participants contributing approximately 52,873 person-years of follow-up.  

The mean follow-up duration per participant was approximately 2.93 years. 

Physical activity was captured from multiple sources, including wearable devices, recorded gym attendance and participation in organised fitness events such as parkrun.  

Participants were grouped according to their average recorded moderate-to-vigorous physical activity: 

  • No recorded physical activity 
  • Low physical activity: 1 to 59 minutes a week 
  • Medium physical activity: 60 to 149 minutes a week 
  • High physical activity: 150 minutes or more a week.  

Researchers looked at how these physical activity levels were associated with achieving target glycated haemoglobin, or HbA1C levels, which indicate blood sugar control over time; starting insulin treatment; major adverse cardiovascular events (MACE); heart failure; and microvascular complications including retinopathy, nephropathy and neuropathy.  

Importantly, participants were not assigned permanently to one physical activity category.  Physical activity was updated over time, allowing the analysis to reflect changes in people's activity patterns throughout the study period. The statistical models also adjusted for a range of demographic, clinical and treatment-related factors. 

What were the key metrics tracked? 

To understand how physical activity was associated with the progression of type 2 diabetes, researchers tracked whether participants reached their target HbA1C level, when they started insulin treatment, and whether they developed major cardiovascular events, heart failure or microvascular complications affecting the eyes, kidneys or nerves.  

In line with South African diabetes guidelines, the target HbA1C was ≤7% for participants without a previous cardiac complication and ≤8.5% for those with a cardiac history. 

Higher physical activity was associated with better blood sugar control and delayed insulin initiation 

The results showed a clear association between higher recorded physical activity and more favourable outcomes for people living with T2D. 

Among participants whose most frequently recorded activity level was high: 

  • 44.9% reached their target HbA1C level, compared with 35.6% of participants with no recorded physical activity. 
  • 13.2% started insulin treatment, compared with 16.5% of participants with no recorded physical activity. 
  • 3.7% experienced MACE plus heart failure, compared with 4.8% of participants with no recorded physical activity. 
  • 0.8% experienced heart failure, compared with 1.5% of participants with low recorded physical activity.  

After researchers adjusted for other relevant factors, physical activity remained significantly associated with achieving target HbA1C levels and insulin initiation. Associations were also seen for heart failure and the composite outcome of MACE plus heart failure.  

The findings suggest a potential dose-response pattern, where 150 minutes or more of moderate-to-vigorous physical activity a week was consistently associated with more favourable glycaemic outcomes. https://discovery365-my.sharepoint.com/personal/amalia1_discovery_co_za/_layouts/15/Doc.aspx?sourcedoc={9C8A6F94-CFE2-4E5E-81E5-ABB4D131EE2D}&file=PA-Diabetes-230826-Final-clean---JD CP.docx&action=default&mobileredirect=true 

Activity levels increased after people activated Vitality Active Rewards 

The researchers also explored how participants' recorded physical activity levels changed after activating Vitality Active Rewards. 

Among 7,169 participants with activity information available for both the 12 months before and the 12 months after activating Vitality Active Rewards: 

  • Before activation, 50.4% had no recorded physical activity. After activation, this fell to 23.2%. 
  • Before activation, 11.7% recorded high levels of physical activity. After activation, this more than doubled to 24.9%. 

As this is an observational study, these changes cannot be attributed solely to Vitality Active Rewards. However, they show a strong association between programme activation and greater recorded physical activity across the different activity levels. https://discovery365-my.sharepoint.com/personal/amalia1_discovery_co_za/_layouts/15/Doc.aspx?sourcedoc={9C8A6F94-CFE2-4E5E-81E5-ABB4D131EE2D}&file=PA-Diabetes-230826-Final-clean---JD CP.docx&action=default&mobileredirect=true 

Wearable-device users recorded higher and more sustained levels of physical activity 

Increases in levels of physical activity were particularly pronounced among participants who used wearable devices to record their activity. 

Again, looking at wearable device usage in the 12 months before and after VAR activation:  

  • Among wearable-device users, the proportion recording high physical activity increased from 11.4% before activating Vitality Active Rewards to 32.3% after activation.  

Researchers also looked at a small subgroup that activated VAR but did not use wearables. Before activation, most participants had no recorded physical activity (reflecting lower baseline engagement with manual or app-based tracking). After activation, the proportion with no recorded activity declined, with corresponding increases across the low, medium, and high activity categories. However, the magnitude of change was smaller than in the full cohort and notably less pronounced than among participants with wearable devices. 

And researchers examined a group of participants who activated Vitality Active Rewards in 2016 and remained continuously enrolled over three years: 

Among participants with a linked wearable device, 41.7% recorded at least 150 minutes of physical activity a week at activation, increasing to 50.7% three years later.  The proportion with no recorded physical activity remained low, moving from 5.6% to 4.1%. https://discovery365-my.sharepoint.com/personal/amalia1_discovery_co_za/_layouts/15/Doc.aspx?sourcedoc={9C8A6F94-CFE2-4E5E-81E5-ABB4D131EE2D}&file=PA-Diabetes-230826-Final-clean---JD CP.docx&action=default&mobileredirect=true 

A different pattern emerged among participants without a wearable device. Over the same period, the proportion recording high activity fell from 19.9% to 11.9%, while the proportion with no recorded activity increased from 22.6% to 51%.  

Taken together, these findings suggest an important potential role for technology-enabled activity tracking, alongside personalised goals and behavioural incentives, in helping people sustain physical activity over time. However, the observational study design means the differences cannot be assumed to have been caused by wearable use or the programme itself. https://discovery365-my.sharepoint.com/personal/amalia1_discovery_co_za/_layouts/15/Doc.aspx?sourcedoc={9C8A6F94-CFE2-4E5E-81E5-ABB4D131EE2D}&file=PA-Diabetes-230826-Final-clean---JD CP.docx&action=default&mobileredirect=true 

Why is this research significant? 

Several aspects of the study add to the existing evidence on physical activity and T2D: 

What do these findings mean for people living with type 2 diabetes? 

The study adds real-world evidence to the established role of physical activity in comprehensive T2D management. 

Higher recorded physical activity was associated with better blood sugar control, delayed insulin initiation and more favourable outcomes for certain cardiovascular complications, even after accounting for a range of other demographic, clinical and treatment-related factors. https://discovery365-my.sharepoint.com/personal/amalia1_discovery_co_za/_layouts/15/Doc.aspx?sourcedoc={9C8A6F94-CFE2-4E5E-81E5-ABB4D131EE2D}&file=PA-Diabetes-230826-Final-clean---JD CP.docx&action=default&mobileredirect=true 

Importantly, the findings also illustrate a central challenge in lifestyle-based care: knowing that physical activity is beneficial is different from helping people maintain it over time. 

The patterns seen among Vitality Active Rewards participants, particularly those using wearable devices, point to the potential of combining activity tracking, personalised goals, real-time feedback and behavioural incentives to support sustained physical activity in real-world settings. https://discovery365-my.sharepoint.com/personal/amalia1_discovery_co_za/_layouts/15/Doc.aspx?sourcedoc={9C8A6F94-CFE2-4E5E-81E5-ABB4D131EE2D}&file=PA-Diabetes-230826-Final-clean---JD CP.docx&action=default&mobileredirect=true 

However, the findings need to be interpreted within the study's limitations: Participants came from a privately insured population enrolled in a health-promotion programme, which may limit the extent to which the findings can be generalised to the broader South African population. The researchers were also unable to adjust for certain factors including smoking, alcohol consumption, diet, psychosocial stress and socioeconomic status. https://discovery365-my.sharepoint.com/personal/amalia1_discovery_co_za/_layouts/15/Doc.aspx?sourcedoc={9C8A6F94-CFE2-4E5E-81E5-ABB4D131EE2D}&file=PA-Diabetes-230826-Final-clean---JD CP.docx&action=default&mobileredirect=true 

Most importantly, this was an observational study, so it demonstrates associations rather than establishing cause and effect. https://discovery365-my.sharepoint.com/personal/amalia1_discovery_co_za/_layouts/15/Doc.aspx?sourcedoc={9C8A6F94-CFE2-4E5E-81E5-ABB4D131EE2D}&file=PA-Diabetes-230826-Final-clean---JD CP.docx&action=default&mobileredirect=true 

Way forward: Sustaining physical activity as part of diabetes care 

Overall, the research reinforces the central role of regular physical activity in managing T2D and supports its inclusion alongside appropriate medical treatment and other lifestyle interventions. 

It also highlights the potential value of scalable, technology-enabled approaches that help people turn physical activity recommendations into sustained behaviour. 

The researchers recommend further studies in more diverse and representative populations, investigation of the mechanisms linking physical activity with specific diabetes complications, and assessment of the long-term cost-effectiveness of integrating wearable-linked physical activity tracking into diabetes management. https://discovery365-my.sharepoint.com/personal/amalia1_discovery_co_za/_layouts/15/Doc.aspx?sourcedoc={9C8A6F94-CFE2-4E5E-81E5-ABB4D131EE2D}&file=PA-Diabetes-230826-Final-clean---JD CP.docx&action=default&mobileredirect=true 

Read the full research 

Read the full study: "The association between recorded physical activity levels, glycaemic control and complications of type 2 diabetes: a retrospective longitudinal registry-based South African cohort study."  

Additional reading 

The study builds on other research by Discovery Health and Discovery Vitality into physical activity and major health outcomes. For example: 

Interested in knowing more or reporting on these findings? 

Please contact us on MEDIA_RELATIONS_TEAM@discovery.co.za to request any updated data available since publication and to obtain any further context required. This is consistent with the close used in the recent Hub summaries. 

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