Researchers tested whether adding an exercise tracker to a continuous glucose monitor would help people with type 2 diabetes control their blood sugar better. Over 6 months, 138 people either wore just a glucose monitor or wore both a glucose monitor and a Fitbit exercise tracker. Both groups improved their blood sugar control at first, but the group using both devices maintained their improvements better and stayed more active. The study suggests that combining real-time blood sugar feedback with activity tracking may help people stick with healthy habits longer.

The Quick Take

  • What they studied: Whether adding a fitness tracker (Fitbit) to a continuous glucose monitor helps people with type 2 diabetes keep their blood sugar in a healthy range better than using the glucose monitor alone.
  • Who participated: 138 middle-aged adults (average age 58) with type 2 diabetes who were struggling to control their blood sugar. About 70% were using insulin injections. Participants were randomly split into two groups.
  • Key finding: Both groups improved their blood sugar control significantly in the first 3 months (dropping by 1.5%). However, between months 3 and 6, the group using both devices maintained better control, while the glucose-monitor-only group’s blood sugar started creeping back up. The group with both devices also stayed more physically active.
  • What it means for you: If you have type 2 diabetes, using a glucose monitor combined with an activity tracker may help you maintain better blood sugar control over time. The activity tracker appears to help people stay motivated to exercise, which supports better diabetes management. However, this is one study, and results may vary for different people.

The Research Details

This was a randomized controlled trial, which is considered one of the strongest types of research studies. Researchers divided 158 people with type 2 diabetes into two groups randomly (like flipping a coin). One group wore a continuous glucose monitor (a small device that measures blood sugar throughout the day), and the other group wore both a glucose monitor and a Fitbit exercise tracker. Everyone received diabetes education and dietary counseling. The study lasted 6 months, with participants wearing three different glucose monitors sequentially (two weeks each for 6 weeks total, then continuing). Researchers measured blood sugar control using two methods: time-in-range (how many hours per day blood sugar stayed in a healthy zone) and HbA1c (a blood test showing average blood sugar over 3 months).

This research design is important because it allows researchers to compare two similar groups and see which approach works better. By randomly assigning people to groups, researchers reduce bias. The sequential use of multiple glucose monitors over 6 months provides a realistic picture of how these tools work in real life, not just in a controlled lab setting.

This study has several strengths: it’s a randomized controlled trial (the gold standard), it had a decent sample size (158 people), and it tracked people for 6 months (long enough to see real changes). The completion rate was good (138 of 158 people finished). However, the study doesn’t tell us if results would be the same for younger people, different ethnic groups, or people not on insulin. The journal is peer-reviewed, meaning other experts checked the work before publication.

What the Results Show

Both groups showed impressive improvements in blood sugar control during the first 3 months. Their HbA1c (a measure of average blood sugar) dropped by 1.5%, which is a significant improvement. Their time-in-range (hours when blood sugar was in a healthy zone) improved from 61% to 71%, while time above the healthy range dropped from 35% to 25%. These improvements happened in both groups equally, suggesting that the glucose monitor itself was the key tool driving initial improvement.

However, the story changed between months 3 and 6. The group using only the glucose monitor saw their blood sugar control slip, with HbA1c rising by 0.7%. The group using both the glucose monitor and exercise tracker had a smaller increase of 0.4%, meaning they maintained better control. This difference was statistically significant, meaning it wasn’t due to chance.

The main reason for this difference appears to be physical activity. The group with the exercise tracker maintained their activity levels throughout the study, while the glucose-monitor-only group significantly reduced how much they exercised after month 3. This suggests that the exercise tracker helped people stay motivated to move, which in turn helped them maintain better blood sugar control.

The glucose monitor data showed consistent capture rates (89.8% to 92%), meaning the devices were working reliably and people were wearing them properly. Participants were scanning their glucose monitors 6-7 times per day on average, showing good engagement with the technology. Interestingly, the improvements in blood sugar control happened independent of weight loss, suggesting that the behavior changes (like checking blood sugar and staying active) were more important than losing pounds.

Previous research has shown that continuous glucose monitors help people with diabetes improve their blood sugar control by providing real-time feedback. This study builds on that by showing that adding an activity tracker may help sustain those improvements over time. The finding that exercise tracking helps maintain motivation aligns with other research showing that wearable devices can support long-term behavior change.

This study only included middle-aged people (average age 58), so results may not apply to younger or older adults. About 70% of participants were on insulin, so results may differ for people managing diabetes with other medications or lifestyle alone. The study didn’t measure whether people actually changed their diet or exercise habits beyond what the trackers showed. We don’t know if results would be the same with different glucose monitors or exercise trackers. Finally, the study lasted 6 months, so we don’t know if these benefits continue longer or if people eventually stop using the devices.

The Bottom Line

If you have type 2 diabetes and your blood sugar control isn’t where you want it, a continuous glucose monitor combined with an exercise tracker may help you improve and maintain better control. This is especially true if staying motivated to exercise is challenging for you. Start with the glucose monitor (which provides the biggest benefit), and consider adding an exercise tracker if you struggle to maintain physical activity. Work with your diabetes care team to set realistic goals and interpret your data correctly. Confidence level: Moderate (based on one good-quality study; more research would strengthen this recommendation).

This research is most relevant for people with type 2 diabetes who are struggling to control their blood sugar, especially those on insulin therapy. It may be particularly helpful for people who are motivated by data and feedback. People with type 1 diabetes, prediabetes, or those with excellent blood sugar control may have different needs. Always discuss any new diabetes management approach with your doctor before starting.

Based on this study, you should expect to see significant improvements in blood sugar control within 3 months of starting a glucose monitor. However, maintaining those improvements appears to require ongoing engagement, particularly with physical activity. The benefits seem to plateau after 3 months if you don’t stay active, so long-term success depends on building sustainable habits, not just using the devices.

Want to Apply This Research?

  • Track daily time-in-range percentage (the hours your blood sugar stays in your target zone) and weekly average steps or exercise minutes. Set a goal to maintain or increase physical activity each week, and log it alongside your glucose readings to see the connection between movement and blood sugar control.
  • Use the app to set a daily step goal (start with 5,000-7,000 steps if you’re currently inactive) and sync it with your glucose monitor data. When you see your blood sugar improve on days you’re more active, use that as motivation to maintain the habit. Create weekly reminders to review your combined data and celebrate improvements.
  • Check your glucose readings and activity data together twice weekly (e.g., Wednesday and Sunday). Look for patterns: do your blood sugar numbers improve on days you exercise? Use this information to adjust your activity goals. Share your combined data with your healthcare provider monthly to ensure your diabetes medications are still appropriate as your control improves.

This research describes one clinical trial and should not replace personalized medical advice from your healthcare provider. Before starting a continuous glucose monitor, exercise tracker, or changing your diabetes management plan, consult with your doctor or diabetes educator. Results may vary based on individual factors including age, medications, overall health, and lifestyle. This summary is for educational purposes and does not constitute medical advice. If you have type 2 diabetes, work with your healthcare team to develop a management plan tailored to your specific needs.