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Endurance in Winter

  • The limiter during long exertion is often in the brain, not in empty muscles
  • Stable blood glucose is more important than “as much sugar as possible”
  • TKB strengthens fat oxidation: less dependent on sports drinks and gels
  • Microdoses of carbohydrates (small, early, regular) keep glucose stable
  • The same principles work for a demanding workday

The problem: metabolic dysfunction in endurance athletes

Section titled “The problem: metabolic dysfunction in endurance athletes”

In some endurance athletes, after years of training with structurally high carbohydrate intake, lots of sports drinks and gels, a metabolically vulnerable pattern develops. Aerobic fitness can be fine, while the system still remains dependent on fast carbohydrates.

  • Quickly hungry or restless when food is delayed
  • Dips in concentration, mood or power during long sessions
  • Difficulty going calmly for long without carbohydrate supply
  • Weight gain or fluctuating glucose values, especially with sleep deprivation and stress

The classic story is: glycogen runs out and therefore you stop. In practice, we often see central failure earlier: the brain limits pace and motor control when blood glucose gets too low or fluctuates strongly.

  • Foggy head, irritability, indecisiveness
  • Sudden loss of power and pace that can no longer be maintained
  • The feeling as if the plug is pulled
  • Often rapid improvement after a small glucose correction

TKB is not primarily intended as “never carbohydrates”, but as recovery of metabolic flexibility: primarily using fat at low and moderate intensity and using carbohydrates purposefully when functional.

  • Fewer fluctuations in energy and hunger
  • More flat power during long duration
  • Less dependence on sports drinks and gels
  • Smaller corrections are often enough to keep blood glucose intact

The switch takes time. Fat oxidation grows through calm endurance training and through consistency in nutrition and recovery.


Skating is a strong example because it often lasts long, intensity varies (wind, bridges, accelerations) and the cold places extra demands on fuel, fluid and salt.

Choose a familiar meal that fits your pattern. Keep it calm for the stomach: not extremely fiber-rich and don’t experiment on the day itself.

Practical options:

  • Eggs with vegetables and olive oil or butter
  • Fish or meat with vegetables and a fat source
  • Full-fat yogurt or quark (preferably A2), possibly with nuts

Preparation:

  • Take sufficient salt if you get cramps quickly or sweat a lot
  • Drink 400-600 ml in the 2 hours before

The basis is: small, early and regular. Not late and in large amounts at once.

Starting point for TKB-adapted people:

  • Start within 20-30 minutes with small intake
  • 10-20 g carbohydrates per hour as microdoses (every 20 minutes 3-7 g)
  • At higher intensity or in the second half: scale up to 20-30 g per hour

Examples of microdoses:

  • Glucose tablets: 1-2 per 20 minutes
  • A small piece of gel or chew (not a whole gel at once)
  • Small sip of sports drink, preferably dosed

Even in cold, you lose fluid. Drink small amounts regularly. Make salt part of the plan, especially for tours longer than 2 hours.

  • Guideline: 400-800 ml per hour, depending on duration, wind, clothing and sweating
  • A warm, salty drink (broth) is often ideal: fluid, sodium and comfort
  • Plan fixed drinking moments (e.g. every 20 minutes a few sips)

MomentWhat you do
Start to 30 minSkate in calmly. Start within 20-30 min with microdose (3-7 g) and a few sips of water
30-90 minEvery 20 min: microdose (3-7 g) plus drinking. With wind or accelerations: extra microdose
90-180 minContinue microdoses. Consider 15-25 g per hour if pace increases. Add salt (broth)
After 3 hoursEvaluate: clear head and stable pace? If so, continue with microdoses. For dip: 10-20 g fast
After finishingWithin 1-2 hours: meal with protein, vegetables and fat source. Limit large sugar compensation

A demanding workday is physiologically similar to endurance exercise: the limiter is often in the brain that depends on stable energy and stress regulation.

  • More stable energy level between meals
  • Less need to constantly adjust with snacks
  • Calmer concentration blocks and less afternoon dip
  • First meal: protein plus fat plus vegetables, not sugar-driven
  • Fluid and salt structural (especially with lots of coffee)
  • At beginning dip: micro-correction 5-10 g carbohydrates plus water
  • At clear dip: 10-15 g fast plus water and 5 minutes of movement

  • You can continue at a flat pace without snacking urge
  • The head stays clear and you continue to make good decisions
  • You can drink and take microdoses without gastrointestinal issues
SituationAction
First signs of dip5-10 g carbohydrates plus water, then back to microdoses
Clear dip10-20 g fast plus water; evaluate after 10 minutes
Cramps or fatigue with lots of drinkingThink of salt (not just water)

  • Plan your microdoses (how much per hour and how often)
  • Bring an emergency option (glucose tablets or gel) - only as correction
  • Bring salt (broth or own salt plan)
  • Ensure sufficient drinking
  • Agree with yourself: first 30 minutes calm, don’t push


Veelgestelde vragen

Why do I get a dip during long exertion?

The limiter is often in the brain, not in empty muscles. When blood glucose gets too low or fluctuates strongly, the brain limits pace and motor control. Typical: foggy head, irritability, sudden loss of power.

How many carbohydrates during a long skating tour?

Start with 10-20 g carbohydrates per hour as microdoses (every 20 minutes 3-7 g). At higher intensity or in the second half: scale up to 20-30 g per hour. Small, early and regular - not late and much at once.

What are microdoses of carbohydrates?

Small, frequent amounts such as 1-2 glucose tablets per 20 minutes, a small piece of gel, or a sip of sports drink. The goal is stable blood glucose, not as much sugar as possible.

What should I do with a dip underway?

Take 10-20 g fast carbohydrates plus water. Wait 10 minutes - if the head clears and power returns, continue with microdoses. For cramps: think of salt, not just water.

Does this also work for a demanding workday?

Yes, a demanding workday is physiologically similar to endurance exercise. Stable energy through fat oxidation, with small corrections (5-10 g carbohydrates) for a dip, prevents snacking urge and concentration loss.


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Medical Disclaimer: The information provided by Stichting Je Leefstijl Als Medicijn regarding lifestyle, diseases, and disorders should not be construed as medical advice. Under no circumstances do we advise people to alter their existing treatment. We recommend that people with chronic conditions seek advice regarding their treatment from qualified medical professionals.