Swim Fast: Threshold Sets for Olympic Triathletes!
Wondering how to hold your pace and stay strong during the Olympic triathlon swim?
Swimming efficiently and powerfully at threshold intensity is key for a fast 1500m swim — without draining energy you’ll need for the bike and run.
Why Threshold Swim Training Is Critical for Olympic Triathlons
Threshold training focuses on swimming at the edge of your sustainable effort — improving aerobic capacity, speed endurance, and race-specific pacing.
By working around your critical swim speed (CSS), you teach your body to swim hard without tipping into unsustainable fatigue — perfect for the demands of an Olympic triathlon.
If you haven’t tested your CSS yet, complete a 400m and 200m time trial and use an online CSS calculator to find your ideal training pace.
These 10 essential threshold swim sessions will help you build endurance, efficiency, and speed so you can dominate your race day!
10 Key Threshold Swim Workouts
1. CSS Classic Set
Purpose: Build race-specific endurance at a steady, fast pace.
Warm-Up:
400m easy + 4x50m drills
Main Set:
10 x 100m @ CSS pace (15s rest)
Cool-Down:
200m easy
2. Broken 1500m Set
Purpose: Simulate 1500m pacing while breaking up the effort mentally.
Warm-Up:
300m easy + 4x50m kick
Main Set:
3 x 500m @ CSS pace (20s rest)
Cool-Down:
200m easy
3. Descending Intervals
Purpose: Train to negative-split races and control effort.
Warm-Up:
300m easy + 6x50m drill
Main Set:
4 x 200m descending (each getting faster) (30s rest)
Cool-Down:
200m easy
4. CSS Overload Set
Purpose: Boost resilience just above race effort.
Warm-Up:
400m easy + 6x50m build
Main Set:
• 6 x 100m @ CSS minus 2s (20s rest)
• 6 x 100m @ CSS (15s rest)
Cool-Down:
200m easy
5. Threshold Pyramids
Purpose: Develop pacing awareness and aerobic strength.
Warm-Up:
400m easy + 4x50m drills
Main Set:
100m / 200m / 300m / 400m / 300m / 200m / 100m @ CSS (15–20s rest)
Cool-Down:
200m easy
6. Race Simulation Set
Purpose: Mimic race surges and open-water unpredictability.
Warm-Up:
400m easy + 4x50m sighting drills
Main Set:
6 x 200m @ CSS with mixed effort (50 hard / 50 steady) (20s rest)
Cool-Down:
200m easy
7. Tempo Ladder
Purpose: Build control over longer distances.
Warm-Up:
300m easy + 6x50m kick
Main Set:
100m / 200m / 300m / 400m / 500m @ CSS (20s rest)
Cool-Down: 200m easy
8. Negative Split 400s
Purpose: Train strong race finishes.
Warm-Up:
400m easy + 4x50m drills
Main Set:
5 x 400m (First 200m @ CSS +2s, second 200m @ CSS –2s) (30s rest)
Cool-Down:
200m easy
9. Fast Finish Repeats
Purpose: Improve your finishing sprint.
Warm-Up:
300m easy + 4x50m build
Main Set:
8 x 100m (first 50m @ CSS, second 50m sprint) (20s rest)
Cool-Down:
200m easy
10. Broken 800s
Purpose: Simulate race-day fatigue with minimal rest.
Warm-Up:
400m easy + 4x50m drills
Main Set:
• 4 x 200m @ CSS (15s rest)
• 8 x 100m @ CSS (10s rest)
Cool-Down:
200m easy
Final Tips for Threshold Swim Training
Use a Tempo Trainer: Lock in your pacing without relying on wall clocks.
Focus on Technique: Smooth strokes save more energy than brute force.
Test and Retest Your CSS: Adjust your training paces every 4–6 weeks for accuracy.
Consistent threshold training sets you up to swim fast, finish fresh, and race your best on Olympic triathlon day!
FAQs About Threshold Swim Training for Triathlon
How often should I swim threshold workouts?
Typically 1–2 threshold sessions per week, combined with easy endurance and technique work.
What is CSS and why is it important?
CSS (Critical Swim Speed) represents your sustainable race pace — training at this pace improves endurance without overwhelming fatigue.
Can threshold swim sessions be done in open water?
Yes! If you have a measured course, you can adapt most threshold sets to open water for even better race-specific preparation.
Final Thoughts
Threshold swim training is your key to swimming stronger, pacing smarter, and starting your Olympic triathlon ready to dominate.
Which threshold swim session will you dive into first to boost your race performance?
Always consult with a medical professional or certified coach before beginning any new training program. The information provided is for educational purposes only and is not a substitute for personalized advice.