Threshold Run: Building Speed Endurance

Session Overview

Threshold running is the pace you could sustain for roughly 60 minutes in a race — often described as “comfortably hard.” This 45-minute session develops your ability to hold a faster pace for longer, which directly translates to faster race times over any triathlon distance.

What You’ll Need

• Running shoes suitable for road or path
• GPS watch or a measured route
• Heart rate monitor (optional but helpful)

Warm-Up (10 minutes)

Start with 8 minutes of easy jogging at a conversational pace. Then complete 4 x 20-second strides at 80% effort with 40 seconds easy jogging between each. These strides activate your fast-twitch fibres and prepare your legs for the main set.

Main Set

The main set uses cruise intervals — sustained efforts at threshold pace with short recovery periods.

• 3 x 8 minutes at threshold pace (RPE 7-8 out of 10, heart rate zone 4). You should be able to speak in short phrases but not hold a full conversation
• Recovery: 2 minutes easy jogging between each interval
• Pacing guide: If your 5K PB is 25 minutes, aim for roughly 5:15-5:25 per km. If your 5K PB is 22 minutes, aim for 4:35-4:45 per km

Cool-Down (5 minutes)

5 minutes of easy jogging, gradually slowing to a walk. Follow with gentle stretching focusing on calves, hamstrings, and hip flexors.

Coaching Notes

• Threshold pace should feel controlled, not desperate. If you are struggling to complete the intervals, you are running too fast
• Keep your cadence above 170 steps per minute to reduce ground contact time
• Run the first interval slightly conservatively — it is better to build into the session than to blow up early
• This session works best on a flat route or gently rolling terrain. Avoid steep hills for threshold work