Critical Swim Speed (CSS)
For many triathletes, swimming can be the most challenging discipline to get faster. These same athletes have a tendency to swim nearly the same pace for all training. Despite hours in the pool, they only see small gains in speed. CSS training is a simple way to help an endurance athlete understand pacing, while also improving swim fitness and muscular endurance. This also serves as a method to test our swim fitness throughout the season.
Swim Session Intensity
| Zones | Description | RPE | Rest Interval | Pace |
|---|---|---|---|---|
| 1– Easy | Easy | 1-2 | as needed | Technique or recovery |
| 2– Light Aerobic | Steady | 3-4 | 10-30 sec | CSS + 10 sec - 140.6 pace |
| 3– Moderate Aerobic | Mod Hard | 5-6 | 10-30 sec | CSS + 5 sec. - 70.3 pace |
| 4– Threshold | Hard | 7-8 | 30-60 sec | CSS or Threshold - sprint tri pace |
| 5– Above Threshold | Very Hard | 9-10 | 30-60 sec | Fast as possible |