I’m betting that we’re going to see an increase in a cohort of people who participate in endurance sports succumbing to type 2 diabetes and pre diabetes.
The doctor’s advice of losing weight and eating better will still apply and that may be where an endurance athlete is lulled into a sense of security. By the metrics of the general population, it would appear that an endurance athlete is not that overweight/obese and gets plenty of exercise. The constants that you can’t control, however, is time (old age) and genetics. Overweight and obesity are risk factors, but uncontrolled blood sugars is multifactorial and specific to the individual. A primary care physician may only be versed in dealing with the general risk factors but specific and specialized care may take a more well versed professional.
The biggest thing you can do is to measure and probably decrease your carb consumption. How deep down the rabbit hole of measuring do you want to go? The first part is to measure yourself. If diabetes runs in the family and/or you’ve done some genetic risk factor testing, that’d be a start. One of the best baseline tests of your ability to handle carbs is the Glucose Tolerance Test (GTT). If you go more advanced, and with the help of a physician in the know, you can couple that GTT test with an insulin test. From this, you’ll get a good idea of how you respond to a glucose challenge. The goal with this combo test is to see if you’re in this weird area where you may have glucose control but am seeing some insulin resistance.
The next step is that you can start measuring your post meal blood glucose. Your fasting blood glucose probably won’t tell you much but knowing the trend of your glucose levels after a meal can be pretty eye opening. Maybe some favorite meals in which you thought was healthy is devastating from the perspective of insulin resistance. Finger stick based testing is very cheap nowadays but we’re interested in your post meal trends so some sort of continuous glucose monitoring is most desirable. That’s more expensive and in some countries a prescription is required. From there you can address diet and behavioral changes while getting some immediate feedback through the glucose testing.
Other risk factors with regard to diet include saturated fat consumption. Higher saturated fat consumption increases the chances of insulin resistance. Timing of carb consumption is important. Are you loading carbs throughout the day? Only carb up for your activity and also an appropriate amount. What are your goals for cycling? Health? or Podium finishes? Maybe you don’t need much carbs at all if being a peak performer isn’t your objective.
Do you fast? Evidence shows that fasting every once can have beneficial effects that last. Another behavioral change that should be considered.
I would say the biggest controllable risk factor for endurance athletes and the predisposition for diabetes is behavioral. It’s not knowing how they are being impacted by their diet and not adapting to their aging body.