Ironman 70.3 Swim Training: 10 Tempo Sessions

SUMMARY
Tempo swimming — around 95–98% of CSS pace or RPE 5–6 — builds the aerobic control, rhythm and race-specific durability you need for the 1.9 km Ironman 70.3 swim. These 10 Zone 3-focused sessions help you swim efficiently under pressure and exit the water feeling ready for the bike.

Why Tempo Swim Training Matters for Ironman 70.3

Just like in the bike and run legs, tempo swimming builds the foundation for race-day performance through control, efficiency, and rhythm. Tempo swim training is essential for building race-pace endurance, pacing control, and fatigue resistance, so you can exit the water ready to crush the bike.

The 1.9 km swim at Ironman 70.3 requires you to hold a steady, sustainable pace without overexerting early. Tempo sessions — typically at race pace or slightly faster — teach you how to balance effort, stay efficient and exit the water fresh for the bike.

Practicing tempo swims builds the aerobic endurance and mental control you’ll need to thrive in open water conditions.These 10 key tempo swim workouts will help you swim efficiently, manage effort, and set yourself up for a successful race day!

Zone 3 Tempo Metrics for 70.3 Swim Training

• Effort (RPE): 5–6 out of 10 — steady but not max

• Pace Guide: 95–98% of CSS pace or ~70.3 swim pace

• Heart Rate (if tracked): 80–87% of max HR (if using HR-capable chest strap or swim watch)

• Use with: FLJUGA’s CSS and HR zone calculators

10 Key Tempo Swim Workouts for Ironman 70.3

1. Steady 400s

Purpose: Build aerobic control across mid-length intervals

Warm-Up: 300 freestyle + 4 x 50 drill/swim
Main Set: 3 x 400 @ Zone 3 (30 sec rest between)
Cool-Down: 200 easy

2. Broken Distance Repeats

Purpose: Accumulate sustained Zone 3 volume with short recoveries

Warm-Up: 400 swim + 4 x 50 build
Main Set: 6 x 300 @ Zone 3 (20 sec rest between)
Cool-Down: 200 pull + 100 easy

3. Pull Strength Set

Purpose: Build upper-body endurance with pull buoy

Warm-Up: 300 swim + 4 x 50 pull
Main Set: 3 x 400 pull @ Zone 3 (45 sec rest between)
Cool-Down: 200 swim

4. Long Continuous Swim

Purpose: Hold aerobic effort for uninterrupted endurance

Warm-Up: 300 easy
Main Set: 1 x 1500 @ Zone 2/3
Cool-Down: 200 swim

5. Distance Ladder

Purpose: Build endurance and rhythm over progressive distances

Warm-Up: 300 swim + 4 x 25 fast
Main Set: 200 / 400 / 600 / 400 / 200 @ Zone 2/3 (30 sec rest between)
Cool-Down: 200 swim

6. Mid-Long Repeats

Purpose: Develop control through moderate-length aerobic efforts

Warm-Up: 300 swim + 4 x 50 build
Main Set: 3 x 500 @ Zone 3 (45 sec rest between)
Cool-Down: 200 easy

7. 1000 + 500 Combo

Purpose: Combine long continuous effort with repeatable aerobic work

Warm-Up: 300 swim
Main Set: 1 x 1000 @ Zone 3 + 2 x 500 @ Zone 3 (30 sec rest)
Cool-Down: 200 swim

8. Tempo + Technique Focus

Purpose: Hold aerobic pace while maintaining good form

Warm-Up: 300 swim + 4 x 25 drill
Main Set: 3 x 400 @ Zone 3 + 4 x 50 drill/swim (20 sec rest)
Cool-Down: 200 swim

9. Tempo 100s Block

Purpose: Maintain Zone 3 rhythm with short repeat intervals

Warm-Up: 300 swim + 4 x 50 build
Main Set: 10 x 100 @ Zone 3 (15 sec rest between)
Cool-Down: 200 easy

10. Race Simulation Swim

Purpose: Mimic 70.3 swim pacing under realistic conditions

Warm-Up: 300 swim
Main Set: 1 x 1900 @ Zone 2/3
Cool-Down: 200 swim

Why These Tempo Sessions Work

• Develop Race-Specific Endurance: Hold a strong pace for the full 1.9 km swim.

• Enhance Pacing Control: Manage your energy to feel strong for the bike.

• Increase Open Water Confidence: Practice sighting and long continuous swimming.

• Improve Technique Under Fatigue: Stay efficient even in the second half of the swim.

Common Mistakes with Tempo Swim Training

• Swimming Too Hard: Zone 3 is controlled — don’t turn it into a race.

• Neglecting Form: Maintain good technique, especially when tired.

• Skipping Recovery Swims: Balance tempo with easy technique sessions.

• Not Practicing in Open Water: Simulate race conditions occasionally.

FAQs About Tempo Swim Training for Ironman 70.3

How often should I include tempo swim sessions?

1–2 tempo-focused swims per week, balanced with drills and long aerobic swims, works well for most athletes.

Is it better to swim these sessions in a pool or open water?

Both — pools are great for pacing control, but open water builds confidence and sighting skills.

How do I pace myself correctly in a tempo swim?

Use a tempo trainer or set target splits slightly slower than your 400m time trial pace for 70.3 racing.

Final Thoughts

Tempo swim training helps you build race-day endurance, efficient pacing, and confident execution for your Ironman 70.3 swim. By targeting Zone 3 regularly, you’ll condition your body to hold effort under fatigue while keeping your technique intact.

Over time, you’ll exit the water fresher, more consistent and better positioned to attack the bike. Don’t just complete the swim — use it as a strength.

Which tempo swim workout will you start with to level up your swim 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.