Executing the Long Run Correctly: Pace, Distance, and Frequency

Introduction

Ask any full-marathon runner: “What is the most important workout in training?” Nine out of ten will answer “the long run.” The long run builds your aerobic base, trains fat-burning efficiency, strengthens lower-body muscular endurance, and serves as a crucial training ground for mental toughness. However, the long run is also the most frequently misused workout: running too fast, too far, too often, or conversely, jogging along lazily every time without any stimulus at all. A proper long run requires a clear understanding of the “why” behind it.

The Physiological Basis of the Long Run

The main purposes of the long run include the following aspects:

• Increasing mitochondrial density: Mitochondria, responsible for aerobic metabolism in muscle cells, increase in number under sustained aerobic stimulation, making the body more economical at the same pace.
• Enhancing fat burning: Low-intensity long runs train “fat oxidation enzymes,” allowing the body to rely more on fat as an energy source in the later stages of a marathon when glycogen stores are depleted.
• Strengthening tendon and joint adaptation: Hours of continuous running stimulus help the Achilles tendon, patellar ligament, and tibia better withstand the impact of long distances.
• Gastrointestinal habituation: Practicing fueling during long runs helps the gut gradually adapt to digesting energy gels and sports drinks under exercise conditions.

Pace Setting: Slow Is More Important Than Fast

Long-run pace setting is where most people make mistakes. Both research and practical experience point to the same conclusion: most runners run their long runs too fast.

The correct long-run pace should be 60–90 seconds/km slower than your goal marathon pace:

Maintaining this pace, you should be able to speak in full sentences with ease. If you feel extremely fatigued after a long run and cannot complete an easy run the next day, your long-run pace is too fast.

Distance Setting: Progression, Cutback Weeks, and Upper Limits

The Principle of Progression

Long-run distance should be increased every two weeks, with increments of 2–3km, not exceeding 10–15% of your current long-run distance. Rapidly ramping up long-run mileage is the primary cause of stress fractures and overtraining.

Cutback Week

Every third week, schedule a cutback week, reducing the long-run distance by 20–30%. For example:

• Week 1: 20km
• Week 2: 23km
• Week 3 (cutback): 17km
• Week 4: 25km

A cutback week is not slacking off; it is a mechanism that allows the body to “supercompensate.” Often, the long run following a cutback week feels lighter and stronger.

Long-Run Upper Limits

• First-time marathoners: no longer than 32km (running beyond 35km in training does more harm than good).
• Intermediate runners: peak long runs of 32–35km, but capped by time (3–3.5 hours).
• Sub-3 hour aspirants: peak long runs of 35–38km (occasionally), with a paced segment in the latter portion.

Frequency: Once a Week Is Enough

During marathon preparation, performing the long run once a week is sufficient, scheduled on Saturday or Sunday. Adequate recovery days are needed between long runs: an easy run or complete rest the day before, and a 30–45 minute easy recovery run the day after to help clear lactate.

Advanced Technique: Adding Paced Segments to the Long Run

During the base phase, long runs should be entirely easy. However, after the strengthening phase, you can add goal-pace segments to the final 20–30% of the long run:

• 28km long run: first 18km easy, final 10km at goal marathon pace.
• This design simulates the fatigue state of the latter half of a race, training pace control ability, and is a key workout for breaking through plateaus.

Practical Advice

• Choose a flat route for paced long runs: Taipei’s riverside park bike paths span over 50km with flat terrain, making them an ideal environment for runners in Taiwan to execute long runs.
• Carry fuel on long runs: For runs exceeding 90 minutes, consume one energy gel every 40–50 minutes, paired with water or electrolyte drinks, to train your gut’s efficiency during the race.
• Do not run long on an empty stomach: Before a long run exceeding 20km, eat a light meal containing carbohydrates (banana, toast with peanut butter) to avoid low blood sugar compromising training quality.
• Choose the right weather for long runs: In Taiwan, temperatures already reach 28°C or higher by 6–7 AM in summer. Long runs should start before 5:30 AM, or be moved to the evening after sunset.

Conclusion

The long run is the backbone of marathon training and the moment when you have the deepest conversation with yourself. Treat every long run as an investment—do not rush to see immediate returns, but trust that every kilometer of aerobic accumulation is quietly transforming your body, making you stronger, more enduring, and more composed on race day.

Related Reading

• Pace Control for the Long Run: The Long-Term Benefits of Conservative Running
• Long Runs in Half-Marathon Training: Pace Setting for a Weekly 18–22km Run
• Road Running Long-Run Training: Weekly Long Run Distance Progression and Pace Control
• Designing Long-Run Training: Weekly Long Run Distance, Pace, and Fueling Strategies