3800m Ironman Distance Pool Swim Simulation Session

Session Overview

This session covers the full 3800m Ironman swim distance in a pool, building the confidence and aerobic base you need to tackle race day. Using a structured combination of easy and moderate-paced sets, it trains your body to hold form over a long continuous effort — the exact challenge of an open water Ironman swim. Suited to advanced swimmers targeting their first or next full-distance race.

What You’ll Need

• Pool access (25m or 50m)
• Swim cap and goggles
• Pace clock or GPS watch with pool mode
• Pull buoy (optional, for variety)

Warm-Up (400m — approx. 10 min)

Swim 400m easy as 100m freestyle, 100m drills (catch-up and fingertip drag alternating every 25m), 100m easy freestyle focusing on long strokes, 100m pull buoy. Keep the effort conversational — HR Zone 1-2.

Main Set (3000m)

Complete 5 rounds of 600m, with 30 seconds rest after each round. Alternate the effort across the set to build from easy to race pace:

• Rounds 1–2: 600m at easy aerobic pace (Zone 2) — focus on long, efficient strokes and bilateral breathing
• Rounds 3–4: 600m at moderate effort (Zone 3, about 85% CSS) — sustainable but purposeful
• Round 5: 600m at race effort (CSS pace) — push for a strong negative split, last 200m at your best effort

Cool-Down (400m — approx. 8 min)

Swim 400m very easy with focus on technique — try backstroke for 100m, then easy freestyle with exaggerated rotation for the final 300m. Let your heart rate fully drop before exiting.

Coaching Notes

• Practise sighting every 10 strokes even in the pool — it builds the habit before open water
• Don’t go out too hard on rounds 1–2; the goal is to arrive at round 5 with something left
• If you’re new to long pool swims, replace round 5 with an easy effort and add a 6th round once fitness builds
• Target RPE 6–8 across the main set; if you’re above 8 before round 4, slow down
• Total session time: approximately 90 minutes including rest