Open Water Pacing Practice: Build to Race Effort

Session Overview

This 45-minute open water session teaches you to pace your swim progressively, building from aerobic base pace to race-day intensity over a continuous 2km effort. Designed for intermediate triathletes, it replicates the feel of a triathlon swim without the common mistake of going out too hard — one of the most costly errors on race day.

What You’ll Need

• Open water lake, reservoir, or sheltered sea — calmer conditions for pacing work
• Wetsuit if water temperature is below 18°C
• Tow float safety buoy (essential)
• GPS swim watch or a clear buoy circuit to measure distance
• Training partner or supervised venue recommended

Warm-Up (10 minutes)

Swim 400m easy freestyle at comfortable conversational pace. Pause every 100m to check your sighting and breathing. This also helps acclimatise to water temperature. Take 2-3 minutes out of the water to reset before the main set if needed.

Main Set

Swim a continuous 2,000m split into four 500m segments, each slightly faster than the last. There are no formal rest intervals — this is about managing your internal effort gauge. Use landmarks, buoys, or GPS splits to check your pace at each 500m mark.

• 500m at easy aerobic pace (RPE 4-5) — settle into rhythm, sight every 8-10 strokes
• 500m at moderate aerobic pace (RPE 5-6) — slight increase in stroke rate, maintaining form
• 500m at controlled race pace (RPE 7) — purposeful effort, consistent breathing pattern
• 500m at race intensity (RPE 8) — strong finish, maintain sighting discipline to the end

Cool-Down (5 minutes)

Swim 200m easy backstroke or sidestroke back to your exit point. Exit safely, remove your wetsuit, and complete 3-5 minutes of light mobility work on shore — shoulder rolls, hip circles, and calf raises to prevent stiffness.

Coaching Notes

• Always swim with a partner or in a supervised venue — solo open water swimming carries real risk. Never skip this.
• The goal is controlled acceleration, not exhaustion. If you struggle to hold form by segment 3, you started segment 2 too hard.
• To make it easier, reduce to 4 × 400m with 30 seconds rest and a slower build. To progress, repeat the full set after a 5-minute rest.
• Track your 500m split times and repeat this session every 2-3 weeks through your race build to measure improvement.