Glucose: Q & A
ATHLETE: After a hard 3 mile run, at a threshold effort, i ingested some carbs. my glucose is 155 and ketones .3. what does that tell you?
COACH: Your glucose level of 155 mg/dL and ketone level of 0.3 mmol/L after a threshold-effort run and carbohydrate intake suggests the following:
Post-Exercise Glycemic Response
Glucose at 155 mg/dL: This elevation is expected after intense exercise and consuming carbs. Threshold efforts increase stress hormones like cortisol and adrenaline, which can temporarily elevate blood glucose by stimulating glycogen breakdown (glycogenolysis) and gluconeogenesis.
The carbs you ingested likely contributed to this spike as they were rapidly absorbed to replenish muscle glycogen.
Ketone Level of 0.3 mmol/L
Low ketone levels: This indicates that your body is not in a state of significant ketosis at the moment. Exercise and carbohydrate intake reduce ketone production, as your body shifts to prioritizing glucose metabolism over fat breakdown for energy.
After a hard run and carbs, your body focuses on replenishing glycogen stores rather than producing ketones.
What It Tells Us
Glucose Metabolism is Dominant: Your body is primarily using glucose as fuel post-exercise, which is normal given the intensity and carb ingestion.
Ketosis Suppression: Carbohydrate intake after exercise temporarily suppresses ketone production.
Effective Recovery Strategy: Consuming carbs after a threshold run is ideal for glycogen replenishment, particularly if you're preparing for another workout soon.
If you’re targeting a higher fat-adaptation or ketogenic state, spacing carbohydrate intake further from workouts may help maintain higher ketone levels. However, for performance, what you did aligns with the need for quick recovery.
ATHLETE: Great, i prefer a speed recovery for sure. I don't care about being in ketosis, I just always have a low level in the background. why when i don't eat a ketogenic diet do i still have low levels of ketones at all times?
COACH: Having low levels of ketones at all times, even when not on a ketogenic diet, suggests that your body is metabolically flexible and efficient at using fat as a secondary fuel source. Here's why this might happen:
1. High Fat Oxidation Baseline
Daily Activity: If you're physically active, especially with endurance training, your body adapts to utilize fat more efficiently for energy. This adaptation often results in baseline ketone production, even without extreme carb restriction.
Exercise-Induced Fat Adaptation: Over time, endurance training enhances mitochondrial efficiency, leading to increased fat oxidation at rest and during low-intensity activity.
2. Low Glycogen Storage Threshold
Carbohydrate Use During Exercise: Regular high-intensity or long-duration exercise depletes glycogen stores. When glycogen is lower, your body increases fat metabolism, leading to ketone production even with moderate carb intake.
3. Hormonal Balance
Fasting-Like Effects: If you go long periods without eating (e.g., between dinner and breakfast), your body may dip into fat stores overnight, producing a small amount of ketones.
Stable Insulin Sensitivity: If your insulin levels are generally low due to excellent metabolic health, this supports ongoing low-level ketogenesis.
4. Lean Body Composition
With a body fat percentage of 15% and daily exercise, your metabolism might lean toward maintaining a fat-burning state to support your energy needs.
Why It’s Beneficial
Dual Fuel Capability: The constant low-level ketones ensure a backup fuel source, especially during fasting or extended activity.
Efficient Recovery and Performance: Your body’s ability to toggle between glucose and ketones makes you metabolically flexible, enhancing endurance and recovery.
Your consistent background ketones reflect excellent metabolic health and efficient energy utilization, even while prioritizing carbs for recovery and performance!