CSS Test with 400 m and 200 m Time Trials
A 2000 m test session with a 400 m and a 200 m freestyle time trial to calculate your critical swim speed, the base for pace training.
- Duration
- 46 minestimated
- Distance
- 2,000 m
- Effort
- 53
- Level
- Intermediate
- Focus zone
- VO2max
Your values
Targets relative to your threshold values. Enter your values to see absolute numbers.
100% is your threshold pace. Higher values are faster, lower values are slower.
| # | Step | Length | Target |
|---|---|---|---|
| 1 | Warm-upEndurance Easy freestyle | 400 m | 85-92% CSS pace |
| 2 | Rest | 20 s | |
| 4 ×Repeat these steps | |||
| 3.1 | Warm-upRecovery Drill of choice | 50 m | 75-85% CSS pace |
| 3.2 | Rest | 15 s | |
| 4 ×Repeat these steps | |||
| 4.1 | Warm-upTempo Build to 400 m effort | 50 m | 92-96% CSS pace |
| 4.2 | Rest | 20 s | |
| 5 | RecoveryRecovery Easy, get ready | 100 m | 75-85% CSS pace |
| 6 | Rest | 1 min | |
| 7 | IntervalVO2max 400 m time trial, push start, even pace | 400 m | 102-107% CSS pace |
| 8 | RecoveryRecovery Easy swim | 200 m | 75-85% CSS pace |
| 9 | Rest | 3 min | |
| 10 | IntervalAnaerobic 200 m time trial, push start, all out | 200 m | 106-113% CSS pace |
| 11 | Cool-downRecovery Easy choice of stroke | 300 m | 75-85% CSS pace |
About this workout
Critical swim speed, or CSS, is the pace you could sustain for roughly 1500 m. It is calculated from two time trials. After a thorough warm-up you swim 400 m as fast as you can hold evenly, recover with easy swimming and a few minutes of rest, then swim 200 m flat out. Both start with a push from the wall, not a dive.
To calculate CSS, subtract the 200 m time from the 400 m time and divide by two. The result is your CSS pace per 100 m in seconds. If you swim the 400 in 380 seconds and the 200 in 180 seconds, CSS is 380 minus 180, divided by 2, which gives 100 seconds or 1 min 40 s per 100 m.
Enter that value as your threshold pace and every swim session in this library sets its targets from it. Retest every six to eight weeks under the same conditions.
Tips
- Pace the 400 evenly, a fast first 100 spoils the result.
- Ask someone to time you and note your 100 m splits if possible.
- Ignore pace alerts on the watch during the time trials and swim by effort.
- If your 200 is not clearly faster per 100 m than your 400, it was not all out, so repeat the test another day.
Origin
Based on the critical speed concept that Wakayoshi and colleagues described for swimming in 1992.
Good forPoolMasters swimmingStandard-distance triathlonHalf-distance triathlon
Season phaseBaseBuildAny time