Can a month and a half of intense exercise actually improve the health of someone with diabetes?
A recent study published in the journal Experimental Physiology determined that six weeks of an intensive CrossFit program could improve blood sugar levels, reduce insulin resistance, and decrease the risk for heart disease in people with type 2 diabetes.
Type 2 diabetes affects more than 30 million people in the United States and is a complex metabolic disorder.
Some patients’ bodies struggle to produce enough insulin to meet their demands. This is sometimes the result of insulin resistance, a diet high in processed foods, and a lack of exercise.
Other patients’ bodies produce enough insulin, but for reasons still not understood, their body struggles to make use of it properly.
Both of these situations can make it harder to lose weight and easier to gain weight.
Regular exercise is one of the most important prescriptions a doctor can write for a patient with type 2 diabetes. Is exercise in the form of CrossFit the ultimate answer?
What researchers found
CrossFit is a fitness class that combines high-intensity aerobic exercise (such as sprints and box jumps) with high-intensity weightlifting (power cleans, deadlifts), and bodyweight exercises (pullups, rope climbs).
“Sessions range from 8 to 20 minutes in duration and represent a far more time-effective form of exercise than traditional exercise interventions,” explained John Kirwan, executive director of the Pennington Biomedical Research Center at Louisiana State University and co-author of the study.
In the study, researchers concluded that “the postexercise intervention test results showed significant improvements in insulin sensitivity and heart disease risk factors.”
“Importantly, these improvements appeared to be similar to the sort of changes expected from more traditional exercise interventions, despite participants spending considerably less time exercising than such guidelines recommend,” the researchers added.
Kirwan and his department submitted a study proposal to the CrossFit organization in an effort to work together on the study.
“CrossFit provided some, but not all of the cost,” Kirwan told Healthline. “We submitted other proposals to other peer-reviewed internal CCF (Cleveland Clinic Foundation) funding mechanisms to secure additional funding.”
How CrossFit works
Advocates say CrossFit’s success is largely the result of making heavy lifting more approachable and beginner-friendly with an intense yet lighthearted competitive edge that’s present in every class.
Perhaps the most unique aspect of a CrossFit program is it packs a lot into a small time frame. In fact, because the intensity level is so high, many people wouldn’t want to perform the exercise routine for a full hour.
However, people with type 2 diabetes are often overweight or obese. So, regular exercise can be challenging.
Signing up for CrossFit may be as realistic and safe for these people as sending a 9th grader who barely made it on the reserve soccer team to run on the field with the varsity seniors.
“Well, yes, resistance training exercise improves insulin sensitivity, we already know that,” Christel Oerum from DiabetesStrong told Healthline. “CrossFit can be a great tool for increasing your sensitivity to insulin... assuming you don’t get hurt.”
Exercise and diabetes
Oerum has been coaching clients with type 1 and type 2 diabetes for years.
She guides them through adopting a healthier relationship with food and making exercise an everyday part of their life.
“You have to take your starting point into consideration,” explained Oerum. “If you’re obese, elderly, or you haven’t done any exercise in a long time — or ever — hardcore CrossFit is probably not the best place to start.”
While CrossFit does offer beginning level classes, no aspect of a CrossFit program is designed to be gentle or easy.
The next question is whether CrossFit actually provides an experience that’s unique when it comes to battling insulin resistance and high blood sugar.
Or can those same results be achieved through nearly every other type of regular exercise?
“CrossFit is just one type of exercise,” said Oerum.
For many, especially if you have chronic joint pain or other injuries, Oerum said that simply walking every day can have a significant impact on your diabetes goals without the risks that come with the intensity of CrossFit.
For many of her clients with type 2 diabetes, simply sitting and standing repeatedly for a few minutes is a challenge. For some, walking for 30 minutes is a great undertaking.
While CrossFit may certainly demonstrate results, the study’s author acknowledges that the most successful results seen were simply outliers.
“One lady started the intervention clearly motivated,” explained Kirwan, “and ended it quite exhilarated by the experience. The intervention had a surprisingly large effect on her fasting blood sugar, which fell from 250 mg/dL to around 90 mg/dL (normal range) — effectively putting her in remission from her diabetes. While an outlier, such an example provides promise to those who may be pessimistic about the possibilities of these types of interventions.”
Oerum recommends that those with type 2 diabetes approach CrossFit with caution.
“If you can find a controlled environment that teaches you the proper techniques for each lift and takes your starting point into consideration for a more personal experience, that would be the safest approach,” she said.