Zware benen rond 15 km? Dit gebeurt er in je lichaam

Heavy legs around 15 km? This is what happens in your body

Many walkers recognize it during the preparation for the 4 Days. The first kilometers go smoothly, but somewhere aroundĀ 15 to 20 kilometersĀ the legs start to feel heavier.Ā 

The pace drops slightly, muscles feel stiffer and the effort seems greater. That's no coincidence. During prolonged exercise, various processes take place in your muscles and in your brain.Ā 

What happens in your muscles during a long walk?Ā 

Your body mainly uses energy during longer walksĀ carbohydrates and fatsĀ as an energy source. As the effort lasts longer, theĀ glycogen storesĀ in the muscles gradually decreases. Glycogen is the stored form of carbohydrates and an important fuel for muscle activity.Ā 

Research into endurance exercise shows that lower glycogen availability can contribute to:Ā muscle fatigue and a heavier feeling in the legs. Studies on glycogen availability and muscle performance show that reduced glycogen stores are an important factor in fatigue during prolonged exercise.Ā 

In addition, problems arise during prolonged exertionĀ minor damage to muscle fibers. This process, tooĀ exercise-induced muscle damage mentioned, is a normal part of training. During recovery, the body repairs these fibers and adapts, ultimately making muscles stronger and more resilient.Ā 

Research into long-term walking loads shows that clear increases occur in markers of muscle damage and muscle fatigue after long-term loads for distances of 15 to 50 kilometers.Ā 

This is exactly why recovery plays such an important role in preparing for the 4 days.Ā 

Sources:Ā 

  • Burke et al. (2015). Glycogen availability and skeletal muscle adaptations to endurance exercise.Ā 
  • Sousa et al. (2021). Pathophysiology or exercise-induced muscle damage.Ā 
  • Studies on muscle strain during long-distance walks (20–50 km).Ā 

Fatigue is not just in your legsĀ 

It also plays a role during long periods of exertionĀ nervous systemĀ a role. When energy stores decrease and muscles become fatigued, the brain receives signals that the effort is becoming strenuous.Ā 

This can lead to:Ā 

  • decreased concentrationĀ 
  • a higher sense of exertionĀ 
  • motivation dips during long workoutsĀ 

This combination of physical and mental fatigue is a well-known phenomenon during endurance exercise.Ā 

Why recovery is so importantĀ 

The kilometers you make are important, but...Ā real training progression happens during recovery.Ā 

In the hours and days after a workout:Ā 

  • restore muscle fibersĀ 
  • become replenished glycogen storesĀ 
  • become waste materials removedĀ 
  • recovers the nervous systemĀ 

Sufficient recovery helps to prevent fatigue from building up and to start the next training session with fresh legs.Ā 

Practical tips for recovery and energyĀ 

Hydration: more than just waterĀ 

During long walks you lose moisture through sweating. That goes tooĀ electrolytesĀ lost, such as sodium and potassium. These play an important role in fluid balance and muscle function.Ā 

Practical tips:Ā 

  • drink small amounts regularly during long workoutsĀ 
  • at warm weather can be aĀ sports drink with electrolytesĀ helpĀ 
  • drink also after your training to replenish fluid lossĀ 

Energy while walkingĀ 

During prolonged exercise, the body mainly uses energyĀ carbohydratesĀ as fuel.Ā 

For longer workouts, it can help to get small amounts of energy while walking, for example:Ā 

  • fruitsĀ 
  • a energy barĀ 
  • sports nutrition with carbohydratesĀ 

This helps to replenish energy stores and delay fatigue. Ā 

Post-workout nutritionĀ 

After training, the body needs building materials for recovery.Ā 

A combination ofĀ carbohydrates and proteinsĀ can help with:Ā 

  • replenish of glycogen storesĀ 
  • recovery of muscle fibersĀ 

For example:Ā 

  • cottage cheese with fruitĀ 
  • a sandwich with egg or chickenĀ 
  • a recovery shakeĀ 

Walk and stretchĀ 

After a long walk aĀ short cooling-downĀ help to gradually calm the body.Ā 

A gentle walk for a few minutes helps keep circulation going and supports muscle recovery. Then you canĀ light stretchingĀ help to reduce muscle tension and maintain mobility.Ā 

Rest and recovery methodsĀ 

Sleep and relaxation are essential for recovery of both muscles and the nervous system. In addition, many walkers use various recovery methods to stimulate blood flow and help relax muscles, such as:Ā 

CompressionĀ 
For example with recovery boots or compression sleeves to support circulation in the legs.Ā 

MassageĀ 
Massage can help reduce muscle tension. This can be done with one massage mat or for example a massage gun.Ā 

HeatĀ 
Heat can contribute to muscle relaxation and stimulation of blood circulation. For example, some athletes use one for this infrared sauna blanket.Ā 

Cold therapyĀ 
Cold baths or ice baths are sometimes used to reduce inflammatory responses and muscle soreness after strenuous exercise. The effect may differ per person, but in certain situations it is possible cold therapycontribute to recovery after intensive strain.Ā 

Recovery as part of your preparation for the 4 DaysĀ 

While preparing for theĀ 4 daysĀ the emphasis is often on making kilometers. Yet it isĀ the balance between load and recoveryĀ at least as important.Ā 

By consciously paying attention to recovery through nutrition, hydration, rest and recovery methods, you help your body to adapt to the training load. This way you not only work on strong legs, but also on a fresh head for the next training kilometers.Ā 

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2 comments

Tips zijn van harte welkom.
In 2026 niet ingeloot en ik zou graag omdat ik wel in training ben een startbewijs willen bemachtigen.
Het trainen gaat natuurlijk wel door samen met mijn man die wel de 30 km gaat/kan wandelen.

Jolanda Kemper

Handige tips

Bart

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