1. What is Critical Speed in Running?

Definition: Critical speed (CS) is the running velocity that can be maintained for a prolonged period without fatigue, calculated by comparing performance at two different distances.

Purpose: Helps runners and coaches determine optimal training paces and race strategies.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( CS \) — Critical speed (meters/second)
• \( D2 \) — Longer distance (meters)
• \( D1 \) — Shorter distance (meters)
• \( T2 \) — Time for D2 (seconds)
• \( T1 \) — Time for D1 (seconds)

Explanation: The difference in distances divided by the difference in times gives the sustainable speed between these two effort levels.

3. Importance of Critical Speed

Details: Critical speed represents the boundary between heavy and severe exercise intensity domains, helping runners optimize training intensity and endurance.

4. Using the Calculator

Tips: Enter two different race distances and their corresponding times. Typically use races between 1500m and 10,000m for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: What distances should I use for calculation?
A: Use recent race results with significantly different distances (e.g., 1500m and 5000m or 5K and 10K).

Q2: How does critical speed relate to lactate threshold?
A: Critical speed typically occurs at a slightly higher intensity than lactate threshold pace.

Q3: Can I use training run times?
A: Race times are more accurate, but consistent time trial efforts can work if properly executed.

Q4: How often should I recalculate?
A: Recalculate after significant races or every 6-8 weeks during training cycles.

Q5: What's a good critical speed value?
A: This varies by athlete. Elite runners may have CS > 6 m/s, while recreational runners typically range 3-5 m/s.