Negative Split Run: Building Finish Speed

Session Overview

This session trains you to run the second half faster than the first — the hallmark of a well-paced triathlon run. Building negative split discipline reduces blow-ups in races and trains your body to find extra speed when fatigued. Total time approximately 45 minutes.

What You’ll Need

• GPS watch or running app to track pace splits
• Running shoes suitable for roads or trail
• Hydration (optional for sub-45 min session)

Warm-Up (10 minutes)

10 minutes easy jog at RPE 3-4. Include 4 x 20-second strides at the end to activate fast-twitch fibres before the main set.

Main Set

A structured 4km negative split effort. The key is discipline in the first rep — hold back more than feels natural.

• 1km at easy pace (RPE 5) — hold back, this is deliberately slower than comfortable
• 1km at moderate pace (RPE 6) — controlled progression
• 1km at comfortably hard pace (RPE 7) — this should feel challenging
• 1km at race pace or faster (RPE 8-9) — empty the tank in the final kilometre

Rest 2 minutes between each 1km rep. Repeat the full 4km block a second time if you have additional time and energy.

Cool-Down (8 minutes)

8 minutes easy walking and jogging to bring heart rate down. Finish with 5 minutes of static stretching focusing on calves, hamstrings, and quads.

Coaching Notes

• Resist the temptation to go too fast in the first rep — negative splits require early discipline
• Check your pace splits after each rep to confirm you are progressing correctly
• In triathlon, the run often starts with fatigued legs — this session helps you find speed despite fatigue
• Scale back by reducing to 2km blocks, or add a third 4km block for more volume