Lactate Threshold Test

The lactate threshold heart rate is the central datum when setting up heart rate training zones. There’s no magic required to determine the LT heart rate though. Below you will find two different lactate threshold test instructions for measuring ventilatory or lactate threshold. One is higher-tech, based on the test originally developed by Dr Conconi and used by Francesco Moser before his hour record rides. The other is more feel-oriented and requires a high degree of sensitivity to your own body. For either test you must be well rested and must not have been sick in the previous few weeks to get a meaningful result. Choose the one you prefer.

NOTICE: THESE TESTS INVOLVE MAXIMAL EXERCISE. BY CHOOSING TO DO THESE TESTS WITH OR WITHOUT A PHYSICIAN’S SUPERVISION YOU ARE ACCEPTING FULL RESPONSIBILITY FOR ANY POSSIBLE CONSEQUENCES INCLUDING BUT NOT LIMITED TO DEBILITATING INJURY OR DEATH. WE RECOMMEND THAT YOU DO THESE TESTS WITH THE PERMISSION AND SUPERVISION OF A PHYSICIAN. IF YOU ARE OVERWEIGHT, OVER FORTY YEARS OLD, OR HAVE PERSONAL OR FAMILY HISTORY OF HEART DISEASE, CARDIOVASCULAR DISEASE OR FAINTING, DO NOT DO THESE TESTS WITHOUT FIRST CONSULTING WITH YOUR PHYSICIAN.

HIGH TECH THRESHOLD TEST:

You will need a trainer or rollers with resistance, a heart rate monitor, a bicycle with cyclometer (on the rear wheel if you plan to use a trainer), and very light cycling clothing. A power meter is optional. This test will NOT work on the road. If you don’t have a recording heart rate monitor, you will need an assistant with a note pad and a watch to write down your numbers and keep track of time, or a tape recorder into which you can yell your numbers. You must have a fan to cool you as you ride.

1. Calculate your Starting Heart Rate. Take 70% of the maximum heart rate you’ve seen in the last year. If you don’t know your maximum heart rate, use 120 bpm as your starting point to be safe. (If you have a power meter, you’ll use a Starting Power of 100W (men) or 70W (women) rather than a Starting Heart Rate.)

2. Warm up thoroughly: For at least 20 minutes spin along easily on your trainer below your Starting Heart Rate or Starting Power. Gradually ease up to the Starting Heart Rate or Power. When you feel warm and loose, accelerate by four miles per hour for two minutes, then rest by spinning slowly for three minutes and then do two more minutes at the higher pace. Return to the lower pace for five more minutes. Now you are warmed up. Pee, drink or stretch if you need to before starting the main part of the test.

3. Determine the starting speed and gear. By trial and error find the speed that gets you your Starting Heart Rate or Power in a comfortable gear. Be sure to ride that speed for at least a minute so you can see that your heart rate is really stable. You may shift gears as often as needed to keep the cadence comfortable during the test. Make sure the resistance of the trainer is set high enough that you will not be spun out later in the test.

4. Continue at the Starting Speed or Power for two more minutes. Have your assistant write down the starting speed and higher speeds up to 15 miles per hour above the starting speed in 0.5 mile per hour increments vertically down the side of a page of the note pad. (For example:
16.0
16.5
17.0
17.5…)

If you are using power, write down the the Starting Power and higher powers up to 450 W in 10 Watt increments. (for example:

70W

80W

90W

100W…)

5. After two minutes riding at the Starting Speed or Power, accelerate by half a mph or 10W each 30 seconds. At the end of each 30 second period, just before you increase effort, have your assistant write down your current heart rate next to the speed or power you’ve been going in that period. Don’t worry if it seems to be changing at that moment. Just record whatever the monitor says at the 30th second.

6. Record how you feel. Particularly be aware if your breathing is accelerating at all, or a lot. Also note if and when your legs begin to burn even slightly. THE MOST IMPORTANT POINT TO RECORD IS THE HEART RATE AT WHICH YOU ARE FIRST BREATHING TOO HARD TO CHAT COMFORTABLY.

7. Eventually you won’t be able to reach or maintain the new level. Try for at least 15 seconds. If you can’t hold the new level, spin easily for five – ten minutes to clear your legs.

8. Now it is time to process the data. You can do this yourself or contact Scott Saifer to do it for you. (If you are not a Wenzel Coaching client there is a $20 charge, payable by PayPal, Dwolla or credit card. E-mail is best for submitting the data. Email ScottSaifer@www.wenzelcoaching.com or phone (925)-933-7306). You will need to tell him the starting speed or power and the heart rate at each period, as well as when your legs started to burn or your breathing accelerated. An Excel spreadsheet is the best format for submitting the information, but email text is okay. If you choose to do it yourself, make a graph with heart rate on the vertical axis and the power or the cube of speed on the horizontal. The graph should approximate two straight lines with the left points contributing to a steeper slope than the right points. These two lines cross at your anaerobic threshold heart-rate and speed or power. Congratulations, you’ve found your threshold!

THRESHOLD TEST BY FEEL:

You will need a long flat road or a trainer or rollers with resistance, a heart rate monitor, and a bicycle with cyclometer (on the rear wheel if you plan to use a trainer). Wear very light cycling clothing if you do the test on a trainer or rollers. If you test on a trainer or rollers, you will need a fan or wind to cool you as you ride.

1. Pick a starting heart rate. If you have a good estimate of your threshold, start 15 beats below it. If you have no idea of your threshold but you know your maximum heart rate, use 70% of the maximum. If you don’t know your threshold or maximum, use a heart rate which you know you can sustain on a ride of several hours without fatigue. If you have no idea, start from 120 beats per minute.

2. Warm-up by riding easily below your starting heart rate for at least thirty minutes. Warm up longer if you need to. Finish off the warm up with three race pace efforts (not sprints but time-trial pace) of about a minute each separated by three minutes of easy pedaling.

3. Throughout the test change gears as often as necessary to maintain a cadence of 90-110rpm.

4. Cruise along gradually bringing your heart rate up to the starting heart rate. Maintain the heart rate in a five beat range for five minutes. If you have increased breathing enough to make chatting difficult or muscle burn in your legs at the starting heart rate, decrease the starting heart rate by 15 beats and start step four again after a five minute rest.

5. Accelerate enough to increase your heart rate by about five BPM and maintain the new pace for five minutes. By the end of the five minutes you may feel some warmth or burning in your legs and your breathing may be accelerated enough to make chatting uncomfortable. If you have no heat feeling in your legs and your breathing is still normal, repeat step five. (Accelerate a bit and hold it for five more minutes). When you have a little heat or heavier breathing, move to step six. Do not wait for very hot legs or very heavy breathing, just a little heat or a little acceleration of breathing indicates that you are over threshold.

6. When you feel a little heat or a little increase in breathing, you are above your lactate threshold. If you back off by five beats for a few minutes you should go below again and the legs should cool and the breathing return to normal. When this happens, you will know that you are again below threshold. You have now bracketed your threshold in a five beat range.

7. To confirm and refine your threshold measurement, go a little harder and a little easier several times back and forth within the bracket range determined in step 6. You should be able to switch the breathing and leg burning on and off in a range of two or three BPM. Try to find the highest heart rate you can maintain for three minutes or more without leg burning or heavy breathing. This is your anaerobic threshold. Congratulations. If you are on a trainer or rollers, note the speed, resistance setting and gear so you can compare this test to later tests to track your progress.

8. Contact your coach and let him or her know what you’ve determined.