1. What is Critical Swim Speed?

Critical Swim Speed (CSS) is a swimming metric that estimates a swimmer's anaerobic threshold speed. It represents the fastest speed a swimmer can maintain without accumulating lactic acid, making it a valuable training tool for endurance swimmers.

2. How Does the Calculator Work?

The calculator uses the CSS formula:

Where:

• \( D_{400} \) — Distance for 400m swim (typically 400 meters)
• \( D_{200} \) — Distance for 200m swim (typically 200 meters)
• \( T_{400} \) — Time taken for 400m swim (in seconds)
• \( T_{200} \) — Time taken for 200m swim (in seconds)

Explanation: The equation calculates the slope of the distance-time relationship, representing the swimmer's sustainable speed.

3. Importance of CSS Calculation

Details: CSS helps swimmers establish appropriate training zones, monitor progress, and set realistic pace targets for different workout intensities.

4. Using the Calculator

Tips: Enter your best times for 200m and 400m swims. The distances default to 200m and 400m but can be adjusted if you've tested different distances. Times must be in seconds.

5. Frequently Asked Questions (FAQ)

Q1: How often should I test my CSS?
A: Every 4-6 weeks to track improvements in your swimming fitness.

Q2: What's a good CSS value?
A: CSS varies by swimmer ability. Competitive swimmers typically range from 1.1 to 1.8 m/s.

Q3: Can I use different distances?
A: Yes, but standard is 200m and 400m. If using different distances, ensure a significant difference between them.

Q4: How should I warm up before CSS testing?
A: Perform a thorough warm-up (10-15 minutes) including easy swimming and some fast efforts.

Q5: How do I use CSS in training?
A: CSS becomes your threshold pace. Train at percentages of CSS (e.g., 95-105% for threshold sets, 80-90% for endurance).