Cycling Workout

40/20 High-Intensity Intervals

A classic VO2 max interval session with 40 seconds work and 20 seconds recovery. This format maximizes time spent at VO2 max while allowing just enough recovery to maintain intensity.

40/20 High-Intensity Intervals

wattsCalculate
Advanced
Warm up
10:00 @ 106-126W (58% FTP)
Main Set
3:00 @ 130-150W (70% FTP)
3:00 @ 150-170W (80% FTP)
3:00 @ 170-190W (90% FTP)
5:00 recovery @ 100-120W (55% FTP)
Repeat 8 times:
1. Hard: 0:40 @ 250-270W (130% FTP)
2. Easy: 0:20 @ 100-120W (55% FTP)
5:00 recovery @ 100-120W (55% FTP)
Repeat 8 times:
1. Hard: 0:40 @ 250-270W (130% FTP)
2. Easy: 0:20 @ 100-120W (55% FTP)
5:00 recovery @ 100-120W (55% FTP)
Repeat 8 times:
1. Hard: 0:40 @ 250-270W (130% FTP)
2. Easy: 0:20 @ 100-120W (55% FTP)
Cool Down
10:00 @ 100-120W (55% FTP)
Total Duration: 68:00
Photo of Jonas

About the Author

I'm a software developer and cycling enthusiast from Germany with over 10 years of experience. I've personally tested and refined all these workouts over the past years, and I can confidently say they will help improve your cycling performance through structured training.

The 40/20 interval format is a highly effective VO2 max training protocol that alternates between 40 seconds of high-intensity work and 20 seconds of active recovery. This specific work-to-rest ratio has been shown to be particularly effective for improving maximal oxygen uptake capacity (VO2 max) while maintaining high power output throughout the session.

Why This Format Works

  • The 40-second work intervals are long enough to fully stress your aerobic system
  • 20-second recoveries provide just enough time to partially recover, but not completely
  • The 2:1 work-to-rest ratio maintains high oxygen consumption throughout the session
  • Multiple sets allow for a high total volume of high-intensity work

Workout Structure

The workout is structured into three main phases:

1. Progressive Warm-up (20 minutes)

  • 10 minutes steady at 58% FTP to raise core temperature
  • 3 minutes at 70% FTP to begin activation
  • 3 minutes at 80% FTP to further prepare the system
  • 3 minutes at 90% FTP for final preparation
  • 5 minutes recovery at 55% FTP before the main set

2. Main Set (3 x 8 repetitions)

  • Each set consists of 8 repetitions of:
    • 40 seconds at 130% FTP (very hard effort)
    • 20 seconds at 55% FTP (active recovery)
  • 5 minutes recovery between sets at 55% FTP

3. Cool-down (10 minutes)

  • 10 minutes easy spinning at 55% FTP to facilitate recovery

Training Benefits

  • Improved VO2 max capacity
  • Enhanced lactate tolerance
  • Better neuromuscular power
  • Increased anaerobic capacity
  • Improved mental toughness

Tips for Success

  • Focus on maintaining power during the work intervals - don't start too hard
  • Keep pedaling during recovery intervals to maintain blood flow
  • Stay hydrated throughout the session
  • Consider using a fan to help with temperature regulation
  • If needed, you can reduce the intensity by 5-10% while maintaining the interval structure

When to Use This Workout

This workout is best used during a VO2 max focus block, typically 1-2 times per week with at least 48 hours recovery between sessions. It's particularly effective for:

  • Preparing for criterium racing
  • Improving 3-8 minute power
  • Building tolerance for repeated high-intensity efforts
  • Breaking through VO2 max plateaus