Swimming With a CGM: Everything You Need to Know

Spending the day at the beach, lounging in the outdoor pool, or swimming laps at an indoor swimming pool is all possible if you use a continuous glucose monitor (CGM). Swimming is a great way to stay active and keep in shape, and thankfully, due to improvements in technology, swimming with a CGM is perfectly safe. 

Most CGMs are water resistant, but there are still some precautions you’ll want to take while swimming with one to minimize the chances of disrupting its function. In this article, we’re covering everything you need to know about safely and effectively swimming with a CGM!

{{mid-cta}}

Understanding Your Continuous Glucose Monitor’s Water Resistance

A CGM can be life-changing for people living with type one diabetes or type 2 diabetes and for anyone looking to improve their health and longevity through a healthy diet and exercise. This wearable device uses a small sensor inserted just under the skin to send real-time blood sugar readings to your smartphone or other device. 

Depending on your CGM, you’ll need to change the device every 7 to 14 days. Many CGMs are water resistant, but no models are totally waterproof. Signos partners with Dexcom, using their G7 model. The Dexcom G7 CGM is waterproof up to 2.4 meters (or about 8 feet), while the G6 is water-resistant up to that same depth, meaning it can safely be submerged to 8 feet for up to 24 hours if properly installed.^1,2  To be safe, verifying your CGM’s water-resistant capabilities is always a good idea before submerging it in water. 

Remember that just because the sensor is water-proof or water-resistant doesn’t mean the receiver is! Whether you use a designated receiver or your smartphone, you’ll want to keep that out of the water or use a waterproof case to keep it safe. This is important if you’re planning on swimming away from dry land, as your Dexcom sensor needs to be within 20 feet of the receiver to pick up your blood sugar readings. 

<p class="pro-tip"><strong>Learn More: </strong><a href="what-is-a-continuous-glucose-monitor">How Does a Continuous Glucose Monitor (CGM) Work?</a>.</p>

How Water Can Impact Your CGM

Even though your CGM may be waterproof or water resistant up to a certain depth or for a certain length of time, that doesn’t mean water can’t impact its function and usefulness. Certain variables could decrease the adhesion of your sensor or the protective cover you use over it. 

Temperature 

The operating temperature for a Dexcom CGM is between 50°F and 107.6°F.³  If you’re planning on wearing your CGM while in an ice bath or at the sauna, it could malfunction and give inaccurate readings if the temperature is outside this range. Saunas can get as hot as 150°F to 175°F and ice baths are typically between 40°F and 60°F, meaning both of these environments could cause your CGM to give inaccurate readings. Hot tubs are generally safer, as temperatures are generally around 100°F to 102°F. 

Warm temperatures, sweat, and humidity can also cause the bond of your protective bandage to weaken. Be sure to take breaks, dry off, and apply a new bandage as needed when exposed to these conditions. 

Environmental temperature can also impact your phone or receiver’s ability to obtain blood sugar information from the sensor. Extreme cold or extreme heat can drain the device's battery more quickly than usual, leading to unexpected dead batteries. If you’re spending the day at the pool or the beach, be sure to keep your phone or receiver out of the sun, which could cause it to overheat and disrupt transmission from your CGM. 

Water Type

Most CGMs are tested for their water-resistant capabilities in pure water, but swimming in the ocean or a saltwater pool could potentially have a different effect. The impact of salt water on the Dexcom CGM isn’t clear, so it’s a good idea to wear a protective waterproof bandage or armband while swimming in salt water. Saltwater may also cause the adhesive on your protective cover to weaken, and it may need to be changed more often. 

Tips for Swimming With a CGM

Swimming is an underrated and incredibly effective low-impact exercise to help you improve your health and meet your wellness goals. A March 2021 study published in BMC Sports Science, Medicine, and Rehabilitation found that regular swimming improved blood cholesterol markers, lowered blood glucose levels, and decreased blood pressure, BMI, and body fat percentage.⁴

Follow these simple tips to reap all the health and wellness benefits of swimming while keeping your CGM protected:

1. If you can, try to plan your new sensor insertion more than 12 hours before you plan to swim or get the sensor wet. Allowing some time for the device to stick to your skin can help it stay in place more securely, so you get the entire recommended 7 to 14 days out of the device. 
2. Check that your sensor is correctly placed. Water-resistant and waterproof claims only apply to sensors that have been properly put in place. 
3. Keep sunscreen away from your CGM and the protective covering. If sunscreen comes in contact with the sensor, it may cause it to malfunction. Sunscreen can also cause the adhesive from the cover to weaken. 
4. Always check the manufacturer's recommendations for your CGM and water use. The depth and time submerged may be different from model to model. 
5. Wear a waterproof bandage, covering, or armband to keep your sensor protected and secure. This is also helpful if you’re exercising outside of the pool or sweating, as both of these activities can cause the sensor to become displaced. 
6. If swimming in warm weather or out in the sun, be sure to keep your smartphone or receiver in the shade to prevent it from overheating and disrupting your blood sugar readings. 
7. Check your readings more often to be sure the sensor is working and to monitor your blood sugar readings when you’re away from your phone. It may be difficult to hear alerts for high or low blood sugar when you’re in the water. This is especially important if you have diabetes or take blood sugar-lowering medication or insulin. 

Can Signos Help You Reach Your Goals? 

With CGM tracking, in-app nutritionist support, and exercise and nutrition recommendations, Signos is here to help you reach your health, weight, and wellness goals. Check out the Signos Blog to learn more about daily living with a CGM. Learn more about how Signos works, and take our quick quiz to find out if Signos is a good fit for you!

<p class="pro-tip"><strong>Also Read: </strong><a href="questions-to-ask-cgm-provider">10 Questions to Ask Your CGM Provider</a>.</p>