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Lactate Test
The lactate test is one of the most important tools for performance diagnostics in cycling. It enables precise determination of individual training zones and provides insights into an athlete's current performance level. Through regular lactate tests, progress can be objectively measured and training plans optimally adjusted.
What is a Lactate Test?
A lactate test is a medical test procedure to determine the lactate concentration in the blood under stress. Lactate is a metabolic product that is produced during anaerobic energy production in the muscle. The lactate concentration in the blood provides important clues about metabolic stress and the efficiency of energy metabolism.
Physiological Basics
At low exercise intensity, energy is mainly provided aerobically, i.e., using oxygen. As intensity increases, energy demand rises, and the body must additionally use anaerobic energy sources. This produces lactate. As long as lactate production and breakdown are in balance, the lactate concentration in the blood remains low and stable.
Above a certain exercise intensity, lactate production exceeds the breakdown capacity - the lactate concentration increases exponentially. This point is called the anaerobic threshold or lactate threshold and is a central parameter for training control.
Procedure of a Lactate Test
The classic lactate test is performed as a step test on a bicycle ergometer or on a trainer. The load is gradually increased, and at the end of each stage, the lactate concentration in the blood is measured.
Lactate Test Execution
The test procedure consists of 6 steps:
- Preparation and resting lactate
- Warm-up phase
- Step test with increasing load
- Blood sampling after each stage
- Check termination criteria
- Cool-down
Test Preparation
For meaningful results, the following preparations are important:
- 24 hours before the test: No intensive training load
- 3 hours before the test: Last meal (easily digestible, carbohydrate-rich)
- 1 hour before the test: No more food intake
- Sufficient sleep the night before the test
- Normal weight: Have your usual body weight on test day
- No illnesses: Appear healthy and fit for the test
Test Protocol
A typical test protocol looks like this:
The increase typically occurs in 25-watt steps with a stage duration of 3 minutes. For recreational athletes, 50-watt steps or longer stage durations (5 minutes) can also be chosen.
Blood Sampling and Measurement
At the end of each exercise stage, blood is taken from the earlobe or fingertip. The sampling is done using a lancet, the blood volume is only about 20 microliters. The lactate concentration is immediately determined with an electronic lactate meter and documented.
Evaluation and Interpretation
The evaluation of the lactate test is done by creating a lactate curve, where the measured lactate values are plotted against the respective exercise intensity (watt or heart rate).
Lactate Curve
The lactate curve typically shows an exponential course. The X-axis shows power in watts (0-400), the Y-axis shows lactate concentration in mmol/l (0-12). The curve shows marked points for the aerobic threshold (2 mmol/l) and the anaerobic threshold (4 mmol/l).
Important Threshold Values
Aerobic Threshold (AT):
- Lactate concentration: approx. 2 mmol/l
- Maximum exercise intensity at which lactate production and breakdown are still in balance
- Corresponds to approximately 60-70% of maximum heart rate
- Optimal range for basic endurance training
Anaerobic Threshold (ANT):
- Lactate concentration: approx. 4 mmol/l (individually variable)
- Point of steepest lactate increase
- Corresponds to approximately 80-90% of maximum heart rate
- Critical intensity for competition loads
Maximum Lactate Concentration:
- Reached 3-5 minutes after exercise ends
- Provides clues about anaerobic capacity
- Values between 8-15 mmol/l in well-trained athletes
Individual Lactate Curve
The shape of the lactate curve is individually different and is influenced by various factors:
- Training status: Trained athletes have a flatter curve with later lactate increase
- Muscle fiber type: More slow fibers (Type I) lead to lower lactate values
- Metabolic efficiency: Better fat burning reduces lactate production
- Daily form: Fatigue, nutrition, and recovery status influence the curve
Derivation of Training Zones
From the lactate test, precise individual training zones can be derived. These zones enable targeted control of training according to the respective goal.
Important: Training zones should not only be defined by lactate, but also by subjective perceived exertion, heart rate, and power (watt). A combination of all parameters leads to the most precise training control.
Benefits of Lactate Diagnostics
Regular performance of lactate tests offers numerous benefits for training planning and performance development:
Objective Performance Assessment
- Comparability: Measurements are reproducible independently of external conditions
- Progress monitoring: Training successes can be objectively documented
- Early detection: Overtraining or form drops are detected early
- Motivation boost: Visible progress motivates further training
Precise Training Control
- Individual zones: Training is precisely tailored to personal performance capacity
- Avoiding incorrect loads: Too intense or too easy sessions are prevented
- Optimal periodization: Training structure can be planned scientifically
- Competition preparation: Optimal intensity for race efforts can be determined
Health Aspects
- Overload prevention: Chronic overload is avoided through regular monitoring
- Recovery management: Recovery needs can be better estimated
- Injury prevention: Balanced training reduces injury risk
Test Frequency and Timing
For optimal training control, lactate tests should be performed at regular intervals:
Recommended Test Frequency
- Competitive athletes: Every 6-8 weeks during preparation
- Ambitious recreational athletes: Every 10-12 weeks or when changing training
- Recreational athletes: 2-3 tests per year (season start, season peak, season end)
- Beginners: After 3-4 months of training for initial assessment
Optimal Test Times
Checklist: When should a new lactate test be performed?
- After 8-12 weeks of structured training
- When changing training (e.g., from basic endurance to interval training)
- Before important competitions for fine-tuning
- After longer training breaks (injury, illness)
- With unexpected performance drops or stagnation
- When subjective perceived exertion has changed significantly
Limitations and Alternatives
Despite its advantages, the lactate test also has limitations:
Limitations of Lactate Diagnostics
- Snapshot: Test only shows status at test time
- Laboratory conditions: Ergometer test does not correspond to reality on the road
- Invasive procedure: Blood sampling is unpleasant for some athletes
- Cost: Professional tests cost between 80-150 euros
- Influenceability: Daily form, nutrition, and recovery influence the result
Alternative Test Methods
FTP Test (Functional Threshold Power):
- 20-minute maximum test on the bike
- Cost-effective and self-performable
- Determination of threshold power without blood sampling
- Well suited for watt-based training
Spiroergometry:
- Measurement of respiratory gases (oxygen uptake, CO2 release)
- More precise determination of aerobic and anaerobic threshold
- Higher costs than lactate test
- Optimal for detailed metabolic analysis
Heart Rate Variability (HRV):
- Daily measurement of heart rate variability
- Provides insights into recovery status
- Supplement, not replacement for performance tests
- Cost-effective self-monitoring
Field Test:
- Maximum test on known route (e.g., time trial course)
- More realistic conditions than laboratory
- No precise threshold determination possible
- Good for competition preparation
Integration into Training Planning
A lactate test alone does not make good training. The key is the correct integration of test results into a structured training plan:
From Diagnostics to Training Planning
Workflow: From Test to Training Plan
- Perform lactate test
- Determine threshold values
- Define training zones
- Create training plan
- Execute training
- After 8-12 weeks: Retest
This cycle is continuously repeated to optimize training planning.
Practical Implementation
After the lactate test, the following steps should be taken:
- Discussion of results with coach or sports physician
- Establishment of concrete training zones in watts and heart rate
- Adjustment of training plan to individual threshold values
- Regular monitoring of training zones in daily practice
- Documentation of training and subjective perception
- Repetition of test after defined training cycles
Tip: Use a training diary or app to document your training sessions. Note not only objective data (watt, heart rate) but also your subjective perceived exertion. This helps in interpreting future tests and fine-tuning training zones.
Avoiding Common Mistakes
Various errors can occur during the execution and interpretation of lactate tests:
Errors in test preparation:
- Intensive training session the day before the test
- Insufficient carbohydrate intake before the test
- Test during illness or incomplete recovery
- Different test conditions in repeat tests
Errors in test execution:
- Too fast start (too high initial watt)
- Uneven pace during stages
- Premature termination before reaching maximum lactate values
- Incorrect position or ergometer setting
Errors in evaluation:
- Transferring ergometer values 1:1 to outdoor training
- Ignoring subjective perceived exertion
- Too rigid application of training zones
- Missing consideration of external factors (heat, altitude, wind)
Warning: A lactate test does not replace individual perceived exertion! The test results are guidelines that must be compared with subjective perception in training. Listen to your body and adjust intensities as needed.
Conclusion
The lactate test is a proven and precise tool for performance diagnostics in cycling. It enables objective determination of performance status and derivation of individual training zones. Especially for ambitious athletes, regular lactate diagnostics is an important building block for systematic training development and continuous performance improvement.
For optimal results, the lactate test should be performed professionally and the results should be competently interpreted. In combination with structured training, sufficient recovery, and regular progress monitoring, the lactate test is an indispensable tool for anyone who wants to sustainably improve their performance in cycling.
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Last updated: November 11, 2025