Open Water Time Trial: 1900m 70.3 Race Distance Session

Session Overview

A 1900m open water time trial is the ultimate race-simulation swim workout for 70.3 athletes. Swimming the exact race distance in open water conditions — with sighting, navigation, and potential chop — is fundamentally different from covering the same distance in a pool. This session builds confidence in your race-day swim capability while exposing any weaknesses in sighting technique or pacing strategy that would otherwise only emerge on race day.

What You’ll Need

• Approved open water swim venue with buoy navigation (lake, reservoir, or designated sea swim zone)
• Wetsuit (recommended — most UK open water venues require wetsuits below 22°C)
• GPS watch with open water swim mode (Garmin Forerunner 945+ or similar)
• Bright swim cap (safety visibility in open water)
• Safety buoy — mandatory at most UK open water venues
• A swim buddy or lifeguard present — never swim open water alone

Warm-Up

• 5-minute easy swim around the near buoy to acclimatise to water temperature
• 4×50m build efforts — easy to moderate, pausing 30 seconds between each
• 2 minutes floating — shake out shoulders, regulate breathing

Main Set

1900m time trial — start your GPS watch at the go signal

• First 200m: settle into race effort — do not blast off at sprint pace regardless of the adrenaline
• Sighting: raise your head every 8–12 strokes to sight the next buoy — in choppy conditions, increase sighting frequency to every 6
• Buoy turns: approach wide, turn tight, accelerate out — this is a skill that takes practice
• Pacing: target even negative splits — second 950m should be equal to or faster than first 950m
• Final 200m: sprint finish — emptying the tank from the last buoy

Record your total time. This is your 70.3 swim baseline. Track it across sessions to measure improvement.

Cool-Down

• 400m easy backstroke or mixed — bring heart rate down before exiting the water
• 10 minutes post-swim stretching: shoulder cross-body, chest opener, hip flexors

Coaching Notes

Run this session once every 3–4 weeks in your race build. Each time, note your conditions (temperature, chop, current) alongside your time — a 28-minute swim in flat calm and a 28-minute swim in choppy open sea are not equivalent efforts. Advanced athletes should complete this session in race-day kit including wetsuit and goggles to confirm comfortable wetsuit movement before trusting it on race day. If your open water time is more than 10% slower than your equivalent pool time, sighting technique is likely the primary limiter to address.