Open Water 3x800m Tempo Build Swim Session

Session Overview

This open water session builds pace across three 800m efforts, starting at comfortable aerobic effort and finishing at race intensity. It develops open water pacing awareness, practises sighting under fatigue and builds confidence holding race speed over repeated efforts — the exact demands of 1500m or 1900m triathlon swims.

Session Details

• Duration: 45–50 minutes
• Location: open water (lake, reservoir or sheltered coastal venue)
• Equipment: wetsuit if water below 18°C; tow float mandatory
• Intensity: Zone 2 → Zone 3 → Zone 4 across the three main efforts

Warm-Up (10 min)

• 400m easy freestyle, focusing on long stroke and controlled breathing
• Drills in the final 100m: 4×25m single-arm alternating, then 4×25m high-elbow catch focus

Main Set: 3×800m Build

• Effort 1 — 800m: aerobic/Zone 2 pace. Should feel comfortable and conversational. Focus on long strokes, sighting every 12 strokes. Rest: 2 minutes
• Effort 2 — 800m: tempo/Zone 3 pace. Noticeably harder — you should be breathing deeply but not gasping. Reduce sighting to every 15 strokes. Rest: 2 minutes
• Effort 3 — 800m: race effort/Zone 4. Close to your open water race pace. Maintain form under fatigue — this is where the session earns its training value. Shorter, slightly higher stroke rate. No rest after

Cool-Down (5 min)

• 200m easy backstroke or relaxed freestyle
• Exit the water and spend 5 minutes stretching: chest opener, shoulder cross-body stretch and neck rotations

Coaching Notes

• Know your route before you start — sight a specific buoy or landmark for each 800m effort; do not rely on GPS mid-swim
• If water is choppy, reduce effort slightly to maintain efficiency — form breakdown in rough water costs more time than pacing adjustments
• Beginners: substitute 3×400m with 60-second rest intervals and apply the same effort-building principle
• Advanced: add a fourth 800m effort at Effort 3 pace, or tack on a 400m pool CSS set within 30 minutes after exiting the water