Timing Training Analysis: Use Split Times to Identify Your Swimming Weaknesses

Introduction

Many swimmers only record a single total time for each workout, but data like that tells you almost nothing about how to improve. A 100-meter time of 1:05 could mean “fast first 50, fading second 50” or “poor start but steady back half”—two completely different problems requiring entirely different training approaches. Split Time Analysis is a training tool that professional coaches have used for years. This article explains how to build your own split analysis system in personal training to identify the real bottlenecks in your swimming performance.

Basic Concepts of Split Timing

Split times are typically recorded every 25 meters or every 50 meters, depending on race distance:

In swimming competition timing systems, official races typically provide splits every 50 meters; during training, you’ll need a coach to time manually, or a sports watch with split memory function.

Interpreting Key Split Metrics

1. Time from the start to the first 15 meters
This number reflects start technique and underwater dolphin kick efficiency. If this segment is noticeably slower than swimmers of the same level, focus on improving your start action and underwater kicking.

2. Front-back half difference (Negative Split vs. Positive Split)

Most amateur swimmers show a significant positive split—the first 50 is 3–8 seconds slower than the second 50, or even more. This typically reflects insufficient anaerobic endurance or poor pacing sense.

3. Speed loss around turns
In timing data, if one segment (e.g., 25–50 meters) is noticeably slower than others, possible causes include: poor turn technique, insufficient underwater kicking after the turn, or that segment being the point where fatigue begins to set in.

Building Your Personal Analysis System

Tool Requirements:

• A sports watch with split memory (or ask a coach to help with timing)
• A logbook or spreadsheet
• Regular standard test distances (recommended every 2–4 weeks)

Analysis Steps:

1. Swim a maximal effort test over your target distance, recording each split time
2. Calculate the front-back half difference (back half - front half) to understand the degree of positive/negative splitting
3. Identify the slowest split and hypothesize possible causes
4. Design targeted training for that segment (e.g., start practice, turn practice, back-half aerobic endurance training)
5. Retest after 4 weeks and compare the data changes

Common Weakness Types and Corresponding Training

• Weak start: Increase start block practice, add 5–10 starts per session, focusing on flight angle and entry posture
• Front half too fast (large positive split): Strengthen back-half aerobic endurance; practice starting at 90% of target pace, then maintaining or accelerating in the back half
• Weak turns: Do dedicated turn practice every session, record speed loss around turns, and quantify improvement
• Severe back-half slowdown: Increase aerobic base training volume, lower target speed, and build back-half holding ability before pursuing speed

Practical Recommendations

1. Build a personal PB split database: Record the complete splits of every personal best, using them as reference targets for future races.
2. Share data with a coach or training partner: Two people looking at the same split data often spot issues that one person analyzing alone would miss.
3. Compare split patterns across different distances: The problems in a 50-meter and a 200-meter race may differ; analyze each separately to find the accurate issue.
4. Record splits on training days too: Not just on test days—record regularly during regular training to understand the accumulation of training effects.

Conclusion

Split time analysis is a tool that turns feelings into data and vague “swimming poorly” into concrete, actionable improvement plans. Develop the habit of regular testing and split recording, and your training will no longer be just stacking hours on feel, but systematic progress with goals, direction, and measurement.

Related Reading

• Post-Race Performance Analysis in Swimming: Data Interpretation and Improvement Directions from Split Timing
• Post-Race Analysis for Swimmers: Finding Your Next Training Direction from Race Data
• Post-Race Performance Analysis in Swimming: A Systematic Approach to Identifying Technical Errors via Video Review
• Studying Opponents in Swimming Races: How to Analyze Competitors’ Technical Characteristics