Lactate Threshold explained

Every Racer Needs a Bigger Hole

A plastic cup. A kitchen faucet. And a hole.

In the video above, Sam uses a simple plastic cup with a hole in the bottom to demonstrate how your body's ability to process (or "buffer") the lactate that accumulates during hard effort reaches a tipping point.And that tipping point forces us all to slow down. Back off. Cry uncle. But that tipping point, which is mostly genetically defined, can be improved with very specific practice.

Sharpen your No. 2 Pencils

​But first — a test.

You HAVE to determine what your Lactate Threshold is in order to learn your power training zones. Once you have your zones defined — and entered into a cycling computer — you can then perform workouts designed to increase your efficiency and power at threshold. ​

If you don't go to a professional athletic performance testing facility for an actual lab test, these two approaches, below, will serve you well.

Step by Step FTP Test

I highly recommend that you do this on a stationary trainer, using the bike that you intend to race. Be well-rested, and treat this as seriously as a medical test: you're going to be setting your training zones based on the effort you lay down, here.

  1. 20 minutes easy warm up
  2. 3 x 1-minute wind ups with a minute rest between (100 RPM pedal cadence)
  3. 5 minutes easy
  4. 5 minutes all out (hard at first, but not so hard that you can't complete the effort)
  5. 10 minutes easy
  6. This is it! 20-minute time trial effort (like the previous 5-minute all out effort, keep in control, hard but steady. You don't want to over cook it and die at the end) If you're using Heart Rate, have a friend record your heart rate from your monitor EVERY MINUTE during this time trial, or hit a lap timer on your monitor so it can give you an AVERAGE HEART RATE from JUST this 20 minute segment.
  7. 10 to 15 minute cool down

My favorite Threshold Test

Rubber Glove FTP test by TheSufferfest

The video, "Rubber Glove" by The Sufferfest is my hands-down, no-brainer favorite way to endure the sheer self-inflicted brutality that is a threshold test. Energizing music, clear on-screen instructions, and excellent pacing insures that you'll get a great estimation of your actual threshold. Highly, highly recommended.

​Now, you have to do a little maffs…

If you are using a heart rate monitor, calculate your average heart rate over the 20 minute time trial interval portion of the test. That's as close to your Lactate Threshold Heart Rate as you can get without actually going to a lab and having the lactate in your blood measured during a test.

If you used a power meter, calculate your average wattage for the 20 minute interval. Then, take this figure and multiply by x0.95. (e.g. a 225w average x 0.95 = 209w FTP)

Next, calculate your Training Zones
Now that you've determined what your Lactate Threshold Heart Rate is (if you're using a heart rate monitor) or your Functional Threshold Power (if you're using a power meter) use the percentages given in the video or found here to calculate your zones. It's a simple matter of dividing your threshold by the low and high ends of the percentages given. Enter your numbers into your computer, and apply yourself to the following excellent workouts.


The classic 2x20 is a very flexible — and very challenging workout. You can adapt the time segments and intensities to your needs and level. For example, instead of 20 minutes at threshold, you might want to start with 7 or 10, and make 20 minutes your goal.

  • 10 mins easy warm-up (Z1)
  • 1 min all-out sprint (Z N/A)
  • 3 mins prep (Z2)
  • 20 mins Z4 (3.8–4.1)
  • 5 mins recovery (Z2)
  • 20 mins Zone4 (Z3.8–Z4.1)
  • 10 mins easy spinning (Z1)


    Whereas 2x20's train your body to handle sustained efforts at threshold, Over/Unders train you to surge and recover. This is important for racing, in that it helps you learn to handle repeated surges in speed with little recovery in between. The period of time "under" helps you to recover. Since you do multiple sets of "under-over-under," you begin to handle more and more lactate over time.

    • 10 mins easy (Z1)
    • 1 min all-out (Z N/A)
    • 5 min under-over-under
      (2 min Z3.8
      1 min Z4.2
      2 min Z3.8)
    • 3 min recovery (Z2)
    • Repeat Under-Over-Under set with rest 2 more times
    • 10 minute cool-down (Z2)

    Cruise Intervals

    ​Cruise intervals are the perfect blend between "2x20's" and "Over/Unders." You're going to be working relatively short periods over threshold, but your rest periods aren't remarkably long. This builds your muscular endurance as well as your ability to buffer lactate.

    • ​10 minutes easy warm-up (Z1)
    • 1 minute all-out (Z N/A)
    • 3 mins prep (Z2)
    • 3 to 5 interval sets of 6 to 12 minutes in length, depending on your fitness. Rest period between sets is 1/2 the working interval.

      For example:
      - 6 mins (Z4.2)
      - 3 mins recovery (Z2)
      - Repeat 5X
    • 10 mins cool-down (Z2)
    Sam Lowe

    I've been a road cyclist with a penchant for speed ever since my first-ever paycheck holiday. I blew the whole wad on a turquoise Schwinn Tempo with then-new Shimano 105 indexed shifting way back in 1985. I've been a voracious consumer of racing-oriented information ever since. Training, nutrition, bike fit, racing techniques, and all manner of "kit." Between nearly 30 years of riding, racing, and reading about racing, I'm ready to help you get ready to race.

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