CGM in Cycling – The Evolution and Future Trends

By Jiri Kaloc

The evolution of continuous glucose monitoring has been rapid! It went from a wired Walkman-sized device for diabetics in 1999 to a wireless gadget the size of a coin that athletes use nowadays. Let’s take a quick look at how far has the technology progressed and what can we expect going forward.

The short history of CGMs

Continuous glucose monitoring technology is closely tied to the developments in diabetes treatment. It started as a device that would be used hand in hand with insulin pumps to help diabetics manage their blood sugar continuously. It has gone a long way since then.

1920s: Insulin is discovered.

1960s: The first intravenous insulin pump is made and it’s the size of a backpack.

1980s: The first subcutaneous (under the skin) insulin pump, MiniMed 502, is made and it’s the size of a Walkman.

1999: The first CGM is made. It has long cables connecting the sensor to the recording device. It’s painful to insert, not waterproof and only able to provide 3-days of retrospective glucose data. It has to be calibrated with a fingerstick glucose test.

2003: The FDA approves the first CGM-integrated insulin pump for people with Type 1 Diabetes. It has improved accuracy and wearability.

2012: A new wireless device developed by Dexcom is released that can be worn for 7 days. It gets an app that sends the data to an iPhone.

2014: The Freestyle Libre glucose sensor, which is the size of a coin, is launched. It can be worn for up to 14 days.

2017: The FDA approved the first CGM that doesn’t require calibration with fingerstick measurement.

2020: Supersapiens launches a CGM solution for athletes that is near painless and much more user friendly, with advanced analytical features.

Are today’s CGMs accurate?

The development of new sensors and CGM software continues with newer devices getting progressively smaller, more portable, waterproof, easier to insert, more comfortable to wear, and much more accurate. But even CGM devices that are on the market now are generally accurate and reliable.

You may still occasionally get values that are completely off. The accuracy could still be improved but most often, these mistakes are caused by the delay in glucose equilibrium between the bloodstream and the interstitial space where the glucose sensor is doing the measurements.

The future of CGM

What can we look forward to in continuous glucose monitoring going forward? There are many companies working on making this technology better for diabetics as well as the general population. For example, a new study says that a fully implanted sensor Eversense XL from Senseonics shows promise in safety and accuracy for use over 365 days straight. This would be a major improvement in convenience for diabetics.

There is even more to look forward to for the healthy population. Apple has been working on a non-invasive CGM, which should be integrated into their Apple Watch. And Samsung is working on something similar for their watches. There is also SugarBeat, built by Nemaura Medical, a wireless non-invasive blood glucose monitoring system using a disposable skin patch that lasts for 24 hours.

The world of cycling is excited about CGM

Cycling pros and their coaches make great use of numbers and CGMs offer a great way to quantify fuelling, which is a big part of performance. But it’s not all about performance, CMGs could help improve safety. Some athletes do crazy things to hit their race weight, damaging their bodies and minds in the process. CGMs could serve as a warning sign that keeps them on the safe side of lean.

CGM caught the interest of the cycling community and some even compare it to watt meters when it comes to the potential impact on the sport.

“The fact that you put a patch on that starts measuring internally is a real breakthrough. That’s what’s really going to change everything, just as much as power meters have made changes in cycling. And the power meter is a little bit limited because it only works the few hours you’re on the bike. It doesn’t tell you anything during the other hours of the day. This technology is 24/7,” said Asker Jeukendrup, a renowned sports nutritionist and exercise physiologist who worked with professional cycling teams like Rabobank and Team Jumbo-Visma.

Chris Froome who became a technical advisor and investor in Supersapiens also sees the opportunity: “That’s just going to grow and grow and grow in the next few years. We are going to see them become more important at top-level sport.”