Lactate Threshold Training – An Intro and a Challenge
Training plans that are based on intensity can help you improve your fitness and prevent overtraining and injury. In the
Fitness World group cycling classes we use RPE and heart rate to assess exercise intensity. RPE, while extremely
valuable, is a subjective measure of intensity and is difficult for some individuals to understand. As we have experienced
already, developing training zones based on heart rate prediction equations are not always suitable for everyone.
Developing a training plan based on your personalized response to graded exercise tests or field tests is more
individualized/specific . Unfortunately, lab tests can be quite expensive and costly.
The two trial tests that we performed on Saturday were performed to help you better understand your exercise
response and develop your personal training zones. These tests were developed by Chris Carmichael (Lance Armstrong’s
former coach). These were called Lactate Threshold (LT) Field tests. Lactate Threshold has been shown to be one of the
best predictors of endurance performance. LT is the point at which your body can no longer get rid of the lactic acid
produced by your muscles, and it starts to accumulate in the blood. LT is closely correlated with heart rate and breathing
rate; although, LT can widely vary as a percentage of maximal heart rate (70-90% MHR). Exercising at LT you will notice
that your breathing rate is significantly higher and you may start to feel a burning sensation in your legs. As shown in the
table above, this would be an RPE=7.
Measuring lactate threshold requires a medical test while on a treadmill or stationary bike. It can also be estimated
based on very specific "field tests" on the bike or run. However, since there is the correlation to heart rate, which is
easier to estimate, we can use heart rate to develop your personalized training zones.
The tests that we performed were 8 minutes in duration. Chris Carmichael has indicated that the results of these tests
likely produce a results that are about 10% higher than LT assessed in a lab setting. Therefore, you will notice that your
estimated LT is 90% of your field test result.
LT, unlike maximum heart rate, can improve with training. In addition, the duration you are able to maintain your
intensity in Zones 4-5 will also improve with time. Initially, you may find that you are only able to maintain your intensity
at this level for a few minutes. However, with appropriate training and time you will see an improvement. So stay
tuned for future tests!!
Keep in mind that this was your first test and many factors can impact your performance on any given day, fatigue,
hydration, environment, music, Kristen psyching you out (or up)  So the next time we perform this test I will remind
you to try to control the factors that were present (and led up to) this first test.
Don’t worry if you didn’t have a heart rate monitor or you don’t plan on getting one. You can use the intensity
descriptions above to help you develop a better understanding and ownership of your perceived exertion. In fact, would
encourage everyone to use RPE because there are many variables that can impact your heart rate (as noted above with
performance). So stay connected!
Using power output is another valuable marker of work. Check out the bulletin board for more info and stay tuned for
future emails/articles on the website.
Definition
Lactate Threshold (LT)
Field Test Result
Estimated LT
Training Zone
The highest average heart rate
you achieved in Trial 1 or 2
10% of your LT Field Test
Result
% of LT
1: Active Recovery
<80%
2: Endurance
80-89%
3: Tempo
90-93%
4: Sub threshold
94-99%
5a: Supra threshold
100-102%
5b: Aerobic Capacity
103-105%
5c: Anaerobic Capacity
>105%
Purpose
Used to promote recovery after harder workouts
Intensity level used during the recovery period of interval work
Used for long, endurance workouts and easy speed workout
Builds and maintains aerobic endurance
Intensive Endurance
Just slightly below race pace (depending on the length)
Race pace
Intensity used for intervals, hill work, and tempo work
Intervals in this zone generally have work-to-rest ratio of 3:1 or 4:1
Training at or slightly below your LT helps your body lean to "recycle" the lactic acid
during high intensity work
Used for intervals, hill work, and tempo work; typically used after some Zone 4 time
has already been done
Very short because it is difficult to maintain this level for any length of time.
Speed Endurance
Used for intervals and hill work to improve anaerobic endurance
Intervals in this zone generally have work-to-rest ratio of 1:1, e.g., a 20 second sprint
followed by 20 seconds of easy recovery (Zone 1).
Short-term Sprinting
Intervals in this zone have a work to rest ratio of 1:2 or more
Intensity
RPE
Very Low
3-4
Moderate
5-6
Somewhat
Hard
Hard
6
Very Hard
8
Extremely
Hard
9
Maximal
Exertion
9-10
7