Running Training: Tempo Runs, Threshold Runs, and Their Differences

What is a tempo run vs threshold run?

Tempo runs and threshold runs are both critical components of a well-rounded running training program, designed to enhance aerobic capacity and speed endurance; however, they differ in their intensity, physiological targets, and the specific adaptations they promote within the body's energy systems.

Introduction to Aerobic Intensity

For runners seeking to improve performance, understanding the nuances of different training intensities is paramount. Beyond easy recovery jogs and all-out sprints, two specific types of moderate-to-hard efforts — tempo runs and threshold runs — are often discussed interchangeably, yet they target distinct physiological zones and yield unique benefits. While both aim to improve your body's ability to sustain faster paces, their precise execution and underlying science set them apart. This article will dissect each type of run, highlighting their physiological underpinnings, practical application, and how to effectively integrate them into your training regimen.

Understanding the Tempo Run

A tempo run is a sustained effort at a "comfortably hard" pace, typically lasting 20 to 40 minutes, excluding warm-up and cool-down. It's often described as a pace you could theoretically maintain for about an hour in a race, or roughly 10k to half-marathon race pace for many runners.

• Definition and Purpose: The primary goal of a tempo run is to improve your body's aerobic capacity and efficiency, specifically targeting your ability to run faster for longer periods without accumulating excessive lactate. It trains your body to sustain a higher pace while remaining in a metabolic state where lactate production and clearance are balanced (below the lactate threshold).
• Physiological Basis: The "Comfortably Hard" Zone: Physiologically, a tempo run is performed at an intensity below your lactate threshold, but significantly above your easy-run pace. This zone is often referred to as the aerobic threshold or ventilatory threshold 1 (VT1). At this intensity, your body is primarily using aerobic metabolism for energy, efficiently clearing any lactate produced. Adaptations include:
  • Increased mitochondrial density in muscle cells.
  • Improved capillary density, enhancing oxygen delivery to working muscles.
  • Enhanced fat utilization as a fuel source, sparing glycogen.
  • Improved lactate shuttling and clearance mechanisms.
• Perceived Exertion (RPE) and Heart Rate:
  • RPE: On a scale of 1-10, a tempo run typically feels like a 6-7/10. You should be able to speak in short sentences, but not carry on a full conversation.
  • Heart Rate: Generally falls within 75-85% of your maximum heart rate (MHR), or approximately 80-90% of your lactate threshold heart rate.
• Typical Duration and Structure: Tempo runs are usually continuous efforts ranging from 20 to 40 minutes at the target pace, preceded by a warm-up and followed by a cool-down.
• Key Benefits for Runners:
  • Boosts aerobic endurance and stamina.
  • Improves mental toughness and focus at sustained challenging paces.
  • Enhances running economy.
  • Prepares the body for race-specific paces in longer events.

Understanding the Threshold Run

A threshold run, often synonymous with a lactate threshold run, is an effort performed at an intensity precisely at or very close to your lactate threshold. This is the fastest pace you can sustain where lactate production and clearance are roughly equal, preventing a rapid accumulation of lactate in the blood.

• Definition and Purpose: The main objective of a threshold run is to increase your lactate threshold, effectively allowing you to run at a faster pace before lactate begins to accumulate exponentially and fatigue sets in. It pushes the boundary of your sustainable hard effort.
• Physiological Basis: Pushing the Lactate Threshold: A threshold run targets the lactate threshold (LT) or ventilatory threshold 2 (VT2). At this intensity, your body is working hard to clear lactate as quickly as it's produced. Training at this level forces your body to adapt by:
  • Increasing the number and activity of enzymes involved in aerobic metabolism.
  • Improving the efficiency of lactate transporters (MCTs) to shuttle lactate away from working muscles.
  • Enhancing the buffering capacity of the blood to neutralize acidity.
  • Ultimately, shifting your lactate threshold to a faster pace.
• Perceived Exertion (RPE) and Heart Rate:
  • RPE: A threshold run feels like a 7-8/10. It's "hard but sustainable." You should only be able to utter one or two words at a time.
  • Heart Rate: Typically falls within 85-92% of your MHR, or approximately 90-100% of your lactate threshold heart rate.
• Typical Duration and Structure: Threshold runs can be continuous, but are often structured as intervals (e.g., 2-4 x 10 minutes at threshold pace with short recovery jogs) to allow for more time spent at the target intensity without excessive fatigue. Total time at threshold pace typically ranges from 20 to 40 minutes.
• Key Benefits for Runners:
  • Significantly raises your lactate threshold, allowing for faster sustained running.
  • Improves speed endurance and tolerance to discomfort.
  • Enhances the body's ability to clear and utilize lactate.
  • Crucial for performance in races from 5k to half-marathon.

Tempo vs. Threshold: A Direct Comparison

While both types of runs are vital for improving endurance and speed, their distinctions are critical for targeted training.

Integrating Tempo and Threshold Runs into Your Training

Both tempo and threshold runs serve distinct purposes and should be incorporated strategically into your training plan based on your current fitness level, race goals, and training phase.

• Strategic Placement:
  • Tempo Runs: Excellent for building foundational aerobic fitness, particularly during base-building phases or when preparing for longer endurance events. They can be performed more frequently than threshold runs due to their slightly lower intensity.
  • Threshold Runs: Best utilized during specific race preparation phases (e.g., 8-12 weeks out from a goal race) to sharpen speed endurance and raise your lactate threshold for faster race performance. Due to their higher intensity, they require more recovery and should be limited to 1-2 sessions per week, often alternating with other hard efforts.
• Progression and Periodization: As you get fitter, your tempo and threshold paces will naturally become faster. It's crucial to adjust your training paces accordingly. During a training cycle, you might start with more tempo work and gradually transition to more threshold work as a race approaches.
• Importance of Recovery: Both types of runs are demanding. Adequate recovery (easy runs, rest days, proper nutrition, and sleep) is essential to allow your body to adapt and prevent overtraining.

Practical Tips for Execution

To ensure you're getting the most out of your tempo and threshold workouts, consider these practical guidelines:

• Warm-up and Cool-down: Always begin with a thorough warm-up (10-15 minutes of easy jogging, followed by dynamic stretches) and end with a cool-down (10-15 minutes of easy jogging, followed by static stretches). This prepares your body for the effort and aids in recovery.
• Listen to Your Body: While heart rate and pace are objective measures, your perceived exertion is equally important. If you feel excessively fatigued, adjust the intensity or duration, or take an extra recovery day.
• Using Data: HR Monitors and GPS: Heart rate monitors can provide objective feedback on your effort level, helping you stay within the target zones. GPS watches can help you maintain consistent pacing. However, learn to correlate these numbers with your RPE to develop a strong sense of your body's signals.
• Terrain and Conditions: Be mindful of external factors like hills, wind, and heat, which can affect your pace and heart rate. Adjust your effort based on these conditions, prioritizing the correct RPE and physiological stress over hitting an exact pace.

Conclusion: Elevating Your Running Performance

Tempo runs and threshold runs are powerful tools in a runner's arsenal, each offering distinct physiological benefits that contribute to improved speed and endurance. By understanding their differences, accurately gauging your effort, and strategically integrating them into your training plan, you can unlock new levels of performance. Remember, consistent application, smart progression, and adequate recovery are the keys to harnessing the full potential of these challenging yet rewarding workouts.