Threshold Outdoor Ride: 4×15-Minute FTP Blocks

Session Overview

This structured outdoor threshold ride uses four 15-minute blocks at functional threshold power (FTP) to build sustained cycling strength and metabolic efficiency. Longer than classic 10-minute FTP intervals, the 15-minute blocks train your ability to hold power deep into the bike leg — exactly what separates strong from average athletes on an Olympic or 70.3 course.

What You’ll Need

  • Road bike or TT bike
  • Power meter (strongly recommended) or heart rate monitor
  • GPS computer with power display
  • A flat or gently rolling road with minimal traffic interruptions — a 15-20km circuit works well

Warm-Up (20 minutes)

Ride 15 minutes easy at Zone 1-2, high cadence (90-100rpm). Then do three 30-second efforts building from 80% to 95% FTP, with 90 seconds easy between each. These activating efforts bring your heart rate into the threshold zone before the first interval begins.

Main Set

Complete 4 x 15 minutes at 95-105% of FTP (Zone 4 power, approximately 80-88% of maximum heart rate). Take 5 minutes of easy Zone 1 spinning between each block. Do not stop pedalling during recovery.

  • Block 1: Target the lower end of your FTP range — get into the rhythm
  • Block 2: Settle at your target power — this should feel comfortably hard
  • Block 3: The test — hold the same wattage when fatigue starts accumulating
  • Block 4: The character builder — maintain form, cadence and power all the way through

Cool-Down (15 minutes)

Spin home in Zone 1 for 15 minutes at 90-100rpm. Avoid pushing on the way back — this is recovery time. Hydrate well and refuel with protein and carbohydrates within 30 minutes of finishing.

Coaching Notes

  • Total ride time: approximately 95-100 minutes including warm-up and cool-down
  • Without a power meter, use heart rate Zone 4 (approximately 80-88% of max HR)
  • RPE should be 7-8/10 during intervals — sustainable but genuinely hard
  • Target cadence during intervals: 85-95rpm to protect your legs for subsequent run training
  • Best scheduled mid-week, 2-3 days after a long ride and 1-2 days before a brick or long run

Training at your own risk. The information provided is for general guidance only and is not a substitute for professional medical advice. Please consult a doctor before starting any new exercise programme, especially if you have any pre-existing health conditions.