Diabetes Forecast

A CGM Helps a Cyclist Reach Peak Performance

By Benjamin Page , ,

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Juan Santiago

AGE: 59
HOMETOWN: Kissimmee, Florida
OCCUPATION: Dog groomer
THERAPY: Oral and injected type 2 diabetes medications, meter, CGM

The Saturday before any big cycling event, Juan Santiago turns the back porch of his home in Kissimmee, Florida, into a makeshift bike shop. He checks tire pressure, adjusts the gears, tests the brakes. He gives his bike a good cleaning to remove any mud it may have picked up during training rides.

As he ran down his maintenance checklist on a recent Saturday, Santiago also took a moment to check on himself. He had a new FreeStyle Libre continuous glucose monitor (CGM), and already he loved how the wearable sensor made it so much easier to check his numbers in real time throughout the day. The next day’s event would be his first time taking his new device out for a 50-mile ride.

Cycling wasn’t always a passion. When Santiago, 59, was diagnosed with type 2 diabetes in 2009, he didn’t live a particularly active lifestyle. His doctor prescribed oral and injected type 2 drugs, but after a year, Santiago began looking for ways to change his lifestyle. He saw a poster for Tour de Cure®, a series of cycling events across the country hosted by the American Diabetes Association, and decided to start biking.

Santiago used to rely solely on a meter, but he was having trouble keeping his blood glucose consistent. As a professional dog groomer, he would often forget to check his numbers as he rushed to the next appointment and frequently found himself going unexpectedly low.

That’s why his doctor recommended a CGM. The continuous monitoring would allow him to check his levels more often. Santiago noticed that one of his Tour teammates used the FreeStyle Libre. His insurance didn’t cover it because his treatment doesn’t include insulin, so he bought the CGM out of pocket. (Some people with diabetes, particularly those who take insulin and are at a higher risk of low blood glucose, find real-time CGMs such as those made by Dexcom, Medtronic, and Eversense particularly helpful. Unlike the Libre, they send alerts when glucose is trending low instead of requiring users to scan for a reading.)

To keep a consistent routine, Santiago rides a few times each week. He typically does a 30-mile workout each weekend, on top of a 10- or 20-mile ride once or twice during the week. If he’s too busy, he tries to at least get to the gym for a spin class.

The CGM may make glucose management easier, but he hasn’t abandoned his meter altogether. While he rides with only the CGM, he keeps the meter with him at work as a backup.

How did his new device fare during his most recent Tour? In 2018, Santiago completed the ride in a little more than five hours. In 2019, his CGM helped him stay on the move, avoid time-consuming meter checks, and ultimately shave an hour off his time.

“If I go low on blood sugar, my performance goes low. I have to stop more often. I have to stop longer. I can’t go as fast,” Santiago says. “This year, because I was able to check my blood sugar on time, I was able to adjust and do a better race.”

Here's a list of CGMs and their specifications.

A Day in the Life

7:30 a.m.
After eating an egg sandwich (no cheese) for breakfast, the only thing I’m concerned about is my blood glucose. It’s barely 110 mg/dl. My new CGM makes it easy to see my numbers with the swipe of my phone, so I’ve started checking up to six times a day. I’ll keep an eye on my levels and tell my teammates that I may need to stop if I feel myself going low. Here I go!

8:15 a.m.
After 45 minutes on the road, I approach a stoplight. I quickly check my glucose on my phone: 92 mg/dl—low enough to affect my performance and potentially put me in danger of hypoglycemia. I eat some candy before the light turns green and hope to see an improvement at the next stop.

9:45 a.m.
With a few more miles behind me, I take a break at a rest stop and check my phone to see how I’m doing. My glucose level is back up to 110 mg/dl, so I know I’m in good shape to finish the ride. Plus, I’m making great time! Using my meter in previous races, I had to pull to the side of the road, unpack my lancet and strips, sterilize my hands—all of this was lost time. And if I didn’t check my blood glucose and started going low, this would affect my performance. With my CGM, I caught that I was trending low and was able to adjust on the fly.

11:45 a.m.
Finished in just over four hours—my best ride yet! I mingle with my teammates as we wait for other riders to cross the finish line. I remind myself: It’s not about who finishes first. It’s about seeing so many people with diabetes complete a challenge together.



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