Over Unders Running: Concept, Benefits, and Implementation

What are Over Unders Running?

Over unders running refers to a specific type of interval training that involves alternating between periods of running slightly "over" and slightly "under" your lactate threshold pace, challenging the body's ability to clear and buffer lactate while maintaining a high level of effort.

Understanding the Concept of Over Unders

Over unders running, often referred to as lactate threshold intervals or tempo intervals with surges, is a sophisticated training modality designed to enhance a runner's ability to sustain high-intensity efforts. The core principle involves precisely manipulating running paces around your individual lactate threshold (LT) or functional threshold pace (FTP) for runners.

• "Over" Pace: This segment involves running at an intensity slightly above your lactate threshold. At this pace, lactate production exceeds lactate clearance, leading to a noticeable accumulation of lactate in the bloodstream. This phase aims to stimulate adaptations that improve the body's capacity to buffer and tolerate higher levels of acidity, pushing the anaerobic threshold upwards.
• "Under" Pace: This segment involves running at an intensity slightly below or at your lactate threshold. While still challenging, this pace allows for a partial recovery and an opportunity for the body to clear some of the accumulated lactate. This phase trains the body to efficiently utilize lactate as fuel and improve lactate shuttle mechanisms, enhancing the rate at which lactate can be converted back into glucose or used by other tissues.

The alternating nature of these efforts creates a unique physiological stimulus that is distinct from traditional steady-state tempo runs or high-intensity interval training (HIIT).

The Physiological Rationale: Why They Work

The effectiveness of over unders running is rooted in specific physiological adaptations:

• Lactate Threshold Improvement: By repeatedly pushing above and then recovering slightly below the lactate threshold, the body becomes more efficient at handling and clearing lactate. This shifts the lactate threshold to a higher intensity, meaning you can run faster for longer before significant lactate accumulation impairs performance.
• Enhanced Metabolic Flexibility: This training teaches the body to better utilize both carbohydrates and fats as fuel sources across varying intensities. The "over" segments demand rapid energy production, primarily from carbohydrates, while the "under" segments encourage more efficient fat oxidation and lactate clearance.
• Increased Mitochondrial Density and Enzyme Activity: Regular engagement in over unders stimulates the growth of new mitochondria and increases the activity of enzymes crucial for aerobic metabolism and lactate transport, improving overall aerobic capacity.
• Improved Running Economy: By training the body to operate efficiently at and around the lactate threshold, runners can maintain a given pace with less energy expenditure, leading to improved running economy.
• Neuromuscular Adaptations: The sustained high-end efforts, even during the "under" segments, help improve the recruitment and coordination of muscle fibers, enhancing power and endurance.

Key Benefits of Incorporating Over Unders

Integrating over unders into a training program can yield significant benefits for runners of all distances:

• Superior Race Pacing: By regularly practicing running at and around race pace, athletes develop a better sense of effort and pacing, crucial for optimal race day performance.
• Increased Speed-Endurance: This training bridges the gap between pure speed work and long-duration endurance, allowing runners to sustain faster paces for extended periods.
• Mental Toughness: The constant fluctuation between hard and slightly less hard efforts builds mental resilience and teaches the runner to manage discomfort effectively.
• Specific Preparation for Longer Races: For distances like 10k, half-marathon, and marathon, the ability to maintain a strong effort even when fatigued is paramount. Over unders directly address this need.
• Variety in Training: They offer a stimulating alternative to repetitive tempo runs or track intervals, keeping training engaging and preventing stagnation.

How to Implement Over Unders into Your Training

Implementing over unders requires a good understanding of your current fitness level and target paces.

1. Determine Your Lactate Threshold Pace: This can be estimated from a recent race (e.g., 10k race pace often approximates LT), a time trial (e.g., 30-minute time trial average pace), or through physiological testing (e.g., lactate testing).
2. Define "Over" and "Under" Paces:
   • "Over" Pace: Typically 5-10 seconds per mile faster than your lactate threshold pace, or 95-100% of your VO2max pace, or an RPE (Rate of Perceived Exertion) of 8-9/10.
   • "Under" Pace: Typically 5-10 seconds per mile slower than your lactate threshold pace, or at your lactate threshold pace, or an RPE of 7-8/10.
3. Structure the Workout:
   • Warm-up: Always begin with 15-20 minutes of easy jogging, followed by dynamic stretches and a few strides.
   • Main Set: Consists of repetitions of "over" and "under" segments. The duration of each segment can vary from 1-5 minutes, with total work time often ranging from 20-40 minutes.
   • Cool-down: Finish with 10-15 minutes of easy jogging and static stretching.
4. Progression: Start with shorter "over" segments and longer "under" segments, gradually increasing the duration of the "over" segments or decreasing the "under" segments as fitness improves.

Sample Over Under Workouts

Here are a few examples of over under workouts, assuming your lactate threshold pace is 7:00/mile:

• Beginner Over Unders (Total 20-25 min work):
  • 4-5 repetitions of:
    • 2 minutes at 6:55/mile (Over)
    • 3 minutes at 7:05/mile (Under)
• Intermediate Over Unders (Total 30-35 min work):
  • 3-4 repetitions of:
    • 3 minutes at 6:50/mile (Over)
    • 5 minutes at 7:00/mile (Under)
• Advanced Over Unders (Total 35-40 min work):
  • 3-4 repetitions of:
    • 5 minutes at 6:50/mile (Over)
    • 5 minutes at 7:00/mile (Under)

Adjust paces and durations based on your individual fitness and race goals.

Important Considerations and Potential Pitfalls

While highly effective, over unders training requires careful implementation:

• Not for Beginners: This type of workout is intense and should only be undertaken by runners with a solid aerobic base and experience with faster running.
• Proper Pacing is Crucial: Running the "over" segments too hard or the "under" segments too slow will negate the specific physiological benefits. Use a GPS watch, heart rate monitor, or perceived exertion to stay on target.
• Adequate Recovery: Due to their intensity, over unders workouts demand sufficient recovery. Incorporate them once or twice a week, allowing for easier training days or rest days in between.
• Listen to Your Body: Pay attention to signs of overtraining, such as persistent fatigue, elevated resting heart rate, or decreased performance. Adjust your training as needed.
• Warm-up and Cool-down: Never skip these crucial components to prepare your body for the stress and aid in recovery afterward.
• Nutrition and Hydration: Ensure you are adequately fueled and hydrated before, during, and after these demanding sessions.

Conclusion: Optimizing Performance with Precision Training

Over unders running is a powerful and precise training method that directly targets the physiological mechanisms underpinning endurance performance. By strategically oscillating around the lactate threshold, runners can significantly improve their speed-endurance, metabolic efficiency, and mental fortitude. When incorporated thoughtfully into a well-structured training plan and executed with attention to individual pacing and recovery needs, over unders can be a game-changer for those seeking to unlock their full running potential and achieve new levels of performance.