What cyclists need to know

To learn more about these devices and blood sugar balance in general, three experts discuss the importance of knowing your blood sugar levels, the pros and cons of CGMs, and how to stabilize your blood sugar levels without gadgets. Here are some general tips.

Need to balance your blood sugar levels?

Compared to people with diabetes, people without diabetes usually have more controlled fluctuations in blood sugar levels. However, depending on factors such as food choices and physical activity, spikes and dips can occur, which can lead to a variety of unpleasant symptoms, including brain fog, fatigue, and a sudden drop in energy. there is. Selvi Rajagopalsays M.D., assistant professor of medicine at Johns Hopkins University. bicycle.

For diabetics, large fluctuations in blood sugar levels can start a process of physical effects that can lead to illness and hospitalization. People with diabetes must learn how to structure their meals and activities to keep blood sugar levels within a certain range. According to the group, they also use insulin drugs for this purpose because diabetes is a disease in which the body does not produce or utilize enough insulin. Center for Disease Control. When this happens, excess blood sugar stays in the bloodstream and can cause heart disease and other serious illnesses.

CGM was created to monitor blood sugar levels throughout the day for diabetics. alex larsonsays RDN, a registered dietitian for endurance athletes based in Minnesota. bicycle. Previously, diabetics had to prick their finger or another location on their body and use a strip to measure the glucose level in that drop of blood. They put that strip on a reader and it tells you if your blood sugar is low, in the right zone, or too high.

CGM works differently. These are discs with thin disposable needle sensors that are placed under the skin. The sensor measures blood sugar levels every few minutes and transfers the readings to a smartphone app or meter to record the results. You will need to replace the sensor every few days to keep it clean.

For people with diabetes, a CGM can be life-changing because it allows you to monitor your blood sugar levels without interrupting your test no matter what you’re doing. This is especially important for children with juvenile diabetes because it allows parents and school nurses to monitor them without actually being in the same physical space.

But these days, Larson explains, endurance athletes are turning to CGMs to assess how their bodies are responding to the fuel they burn during training. “There are claims that using CGM increases metabolism and optimizes nutrition through glucose stability,” she says.

Are there any benefits to using a continuous blood glucose monitor?

For cyclists interested in blood sugar levels, there are legitimate benefits to using a CGM.

“The benefit of using CGM is that athletes can learn hands-on how their bodies respond to training and refueling exercises,” says Larson.

CGM data can be used in conjunction with other data, including objective metrics such as heart rate and power, as well as subjective metrics such as perceived exertion and an athlete’s overall mood, to improve performance related to fueling and performance. It will help clarify the problem. nicole rubensteinMS, RD, CSSD, Registered Dietitian, Owner. racer’s edge nutrition Colorado speaks bicycle. “For example, if an athlete’s power starts to drop significantly below target four hours into a ride, we can look at blood sugar data and see if lower blood sugar levels may be contributing to the athlete’s slowing down.” You can see if it is,” she says.

Rajagopal added that there are potential benefits for people who are aware of the signs of hypoglycemia, such as cold sweats, brain fog, fatigue, dizziness, irritability, increased heart rate, and decreased performance during exercise. “I think it can actually be very beneficial in that situation,” she says.

What are the disadvantages of using CGM?

The caveat is that CGMs spit out a lot of data, and there are no established guidelines on how to interpret this data (unless you have a glucose regulation disorder, such as diabetes). Therefore, experts recommend consulting a registered dietitian, primary care physician, or endocrinologist for advice on how to interpret and make decisions based on CGM information.

Additionally, there are currently no studies proving that using CGM improves performance, Larson said. There is also not yet enough evidence to show that they are useful in diagnosing over- or under-fueling, she added. What’s more, these devices are expensive. The average cost of a startup kit is about $1,000, and depending on the CGM, it can cost several thousand dollars per year.

Additionally, relying too much on CGM can lead to food anxiety and unhealthy mental states. Rubenstein said the device could increase the risk of eating disorders. “I’ve seen patients become fixated on blood sugar fluctuations that aren’t clinically important and start restricting their carbohydrate intake as a result,” she says.

This is especially worrying in a sport like cycling, where eating disorders are unfortunately already prevalent.Good example: 1 2022 survey Among approximately 400 elite female cyclists, 13% of participants were receiving treatment for an eating disorder (ED), an additional 28% were at high risk for ED, and a further 32% had no clinical evaluation for ED. The survey found that there is a high possibility that they would have benefited if they had. Responses to a questionnaire regarding attitudes toward food. “We have to be very careful when recommending tools that might cause athletes to become obsessed with food or numbers,” Rubenstein says.

A lack of guidelines on what to do with data can also result in people making misinformed decisions.

“It’s very easy to overanalyze CGM data, and it’s very easy to come to the wrong conclusions,” Rubenstein says. “For example, if eating an apple raises your blood sugar to 140, and just eating ice cream raises your blood sugar to 120, that doesn’t mean ice cream is a healthier option than an apple. ”

Another example: If someone at risk for diabetes notices that their blood sugar levels tend to drop quickly after taking a gel, they simply take more gel to prevent that drop. You might think that is the solution. However, you may benefit from replacing the gel with more complex carbohydrates and combining it with protein or fat. “It’s not necessarily a panacea for people with hypoglycemia,” says Dr. Rajagor. “I’m a little concerned that their management approach will inadvertently change based on the information.”

The truth is, many things (in addition to diet) influence blood sugar fluctuations, including stress, sleep habits, and exercise intensity, Rubenstein says.

To fully interpret CGM data, it must be tracked and processed. ton Other information. “The average person probably won’t sit down for two hours a day to analyze all this data,” Rubenstein says, even though people tend to do so. , added that this approach is not recommended.

So should you get a CGM?

All three experts agree that investing in a CGM is probably not worth it for the average cyclist. Unless, of course, her doctor has directed her to use CGM. “Current literature does not support that claim. We would encourage cyclists and endurance athletes to focus their time, energy and money on developing basic fueling strategies both in and out of training. ,” Larson said.

Rubenstein added that it should be avoided at all costs by people who have or have had an eating disorder or who are at high risk for ED. The same may be true for people with anxiety disorders, Rubenstein notes, since having 24-hour access to glucose data “may increase anxiety.”

If you still want to give it a try, Larson suggests working with a sports nutritionist who can decipher the data and provide context on numbers, diet, and training plans.

How can I balance my blood sugar levels without using CGM?

The truth is, you don’t need a CGM to make smart decisions about your blood sugar levels. Larson educates himself on general fueling guidelines for endurance sports (a registered dietitian can help here too) and tests different forms of fuel to find the best one to last you through your ride. I am suggesting that you find something.

Rubenstein’s advice: Eat a balanced diet consisting of whole foods, adequate fiber, and enough protein and carbohydrates to match the intensity and volume of your training.

Also keep in mind that much of the fuss surrounding CGMs can lead people to believe that carbohydrates are the enemy, when in fact they are not. “Our bodies need carbohydrates to use as fuel,” Larson explains. Sugar can be transported directly to the muscles without the help of insulin, so when we exercise, after eating carbohydrates or sugar, our bodies actually release minimal amounts of insulin. Additionally, exercise increases insulin sensitivity, Larson added. Essentially, she explains, muscles use available insulin more efficiently, both during and after activity.

Finally, and perhaps most importantly, know that “fluctuations in blood sugar levels are normal,” says Rubenstein. When looking at CGM data, the goal is not to have a perfectly flat line, she explains.

Instead, the goal is to have less rapid fluctuations in blood sugar levels, which comes from eating a balanced diet that combines carbohydrates, protein, and healthy fats.

Important points for balancing blood sugar levels

Good news for all CGM enthusiasts. Rajagopal believes that we believe in us. intention We will be able to provide more targeted advice on CGM use to people who do not have diabetes, and people will be able to use CGM on their own without the need for guidance from a medical professional. “I think there are a lot of potential benefits,” she says. “I don’t think we’re there yet.”

In the meantime, she advises focusing on the basic concepts of healthy eating and recommends cyclists spend money on a consultation session with a registered dietitian who can help them develop a fueling plan. I encourage it. “At the end of it all, it’s going to be back to basics: ‘How do we eat?'” says Rajagopal.