6x1km at 10K Race Pace: Speed Endurance Run Session

Session Overview

Six 1km repetitions at 10K race pace develops the lactate threshold running speed that translates directly to faster run splits off the bike in triathlon. This interval session targets the physiological zone between your comfortable aerobic pace and your maximum, building your ability to sustain hard effort over the 5km, 10km, and 21km run legs that define your triathlon finish time.

What You’ll Need

• Running track or flat measured 1km road loop
• GPS watch or running app with pace alerts
• Water bottle accessible between reps
• Race-day running shoes or a faster training shoe

Warm-Up (15 minutes)

10 minutes of easy running at a fully comfortable pace, followed by 4x100m strides — smooth accelerations building to approximately 90% effort with a full walk-back recovery between each. The strides prime your neuromuscular system for faster running without generating significant fatigue before the main set.

Main Set

6 repetitions of 1km at your 10K race pace, with 90 seconds of walking or very easy jogging recovery between each rep. Run each rep as a controlled, sustained effort — not a sprint. The first two reps should feel manageable; the final two should feel genuinely demanding as lactate builds.

• Reps 1-2: 10K target pace, feeling controlled — RPE 7/10
• 90 seconds rest (walk or very easy jog)
• Reps 3-4: Same target pace, starting to feel the effort — RPE 7.5/10
• 90 seconds rest
• Reps 5-6: Push to hold target pace as legs tire — RPE 8-8.5/10

Cool-Down (10 minutes)

10 minutes of easy jogging followed by 5 minutes of static stretching — quads, hamstrings, calves, and hip flexors. Hydrate and eat a recovery snack within 30 minutes of finishing.

Coaching Notes

• Find your 10K pace using a recent parkrun result: your 5K time plus 15-20 seconds per km gives a reasonable 10K pace estimate. If you don’t have a recent time, use the first rep as a benchmark and calibrate from there.
• Common mistake: setting off too fast on Rep 1. Running Rep 6 at the same pace as Rep 1 is the goal — not slowing dramatically by the end.
• Beginner scaling: reduce to 4x1km. Advanced: increase to 8x1km or reduce rest to 60 seconds.
• To simulate race day: do this session the day after a long bike ride, or complete 15 minutes on the turbo before heading out, to replicate the run-off-the-bike sensation of triathlon.