Open Water Mass Start Practice: 45-Minute Race Simulation Session

Session Overview

This 45-minute open water session simulates the chaos and physical contact of a triathlon mass start, building your confidence and race-specific fitness for one of the most demanding moments in any race. Ideal for intermediate swimmers preparing for Olympic or 70.3 distance events.

What You’ll Need

• Wetsuit (if water is below 22°C)
• Swim buoy/tow float for safety
• At least one training partner (mass start practice requires other swimmers)
• Clear buoy or landmark to navigate around

Warm-Up (10 minutes)

Swim 400m at easy effort (RPE 3-4), alternating between freestyle and a few minutes of backstroke to loosen up. Practise sighting every 6 strokes throughout the warm-up — this builds the habit before the main set.

Main Set

The main set focuses on short, hard race-simulation efforts followed by controlled recovery swims. The intensity should mirror what you’ll experience in the first 400m of a race start.

• 3 x race start sprints: Start together in a tight group, sprint 100m hard (RPE 9), then settle into race pace for 100m. 90 seconds rest between each.
• 2 x 300m race simulation: Swim at race pace with your training partner(s) close alongside — deliberately swim within a body’s width of each other to practise physical contact. Focus on maintaining your sighting and rhythm even when bumped. 2 minutes rest between each.
• 1 x 400m time trial: Solo effort at race pace, focusing on steady sighting every 8-10 strokes and controlled turn around a buoy.

Cool-Down (5 minutes)

Easy 200m swim back to shore, focusing on long, relaxed strokes. Take time to float on your back and bring your heart rate down gradually.

Coaching Notes

• The mass start sprint is the most race-specific skill in triathlon swimming — practising it regularly removes the anxiety of race day contact.
• Don’t panic if bumped — stay calm, maintain your stroke rate, and breathe on the side away from contact.
• Easier version: increase rest periods to 3 minutes and reduce race simulation distances to 200m each.
• Harder version: add a 4th race start sprint and increase race simulation efforts to 400m each.