Test your Fitness: Understanding VLamax for Cycling & Running

You’ve probably heard about VO2 max (the measure of your aerobic capacity) but there’s another performance metric that could transform the way you train: VLamax.

Think of it as the “hidden dial” controlling whether you excel at sprinting or endurance. A higher VLamax means explosive speed and power, while a lower one favours long-distance efficiency. Understanding and shaping this could be the key to unlocking your potential as a cyclist or runner.

In this guide, we’ll break down what VLamax is, why it matters, and (most importantly) how you can use it in your training.

Key takeaways at a glance:

• VLamax = maximum lactate production rate (anaerobic capacity)

• High VLamax = sprint power, fast acceleration

• Low VLamax = endurance efficiency, better fat metabolism

• You can test and train to adjust your VLamax

• Use VLamax alongside VO2 max to personalise your training

What is VLamax?

‘VLamax estimates an athlete's maximal-glycolytic rate’ 

- Clark, B., & Macdermid, P. W. (2025). VLamax Correlates Strongly With Glycolytic Performance. Research Quarterly for Exercise and Sport

VLamax stands for maximum lactate accumulation rate. It measures how quickly your body can produce lactate during anaerobic metabolism (energy production without oxygen).

• High VLamax: More glycolytic power for greater sprint and acceleration ability

• Low VLamax: More efficient aerobic metabolism for stronger endurance

In short: VO2 max shows your aerobic ceiling, VLamax shows your anaerobic floor. Together, they define your unique performance profile.

Why Does it Matter?

‘Strong and significant relationships were found between power output in a 15-s isokinetic sprint test and V⁢Lamax.’ 

- Clark, B., & Macdermid, P. W. (2025). VLamax Correlates Strongly With Glycolytic Performance. Research Quarterly for Exercise and Sport

Your VLamax influences:

• Endurance: Lower values reduce carbohydrate burn, delaying fatigue

• Sprint & power: Higher values help you accelerate

• FTP & threshold: It directly impacts Functional Threshold Power (FTP) by affecting lactate clearance

How to Measure VLamax

You can’t just guess your VLamax, it requires specific testing.

Options include:

1. Lab Testing (Gold Standard)

• Short, all-out efforts on a bike or treadmill with blood samples taken

• Highly accurate, but requires access to a sports lab

2. Field Tests (Coach-Supported)

• A typical test protocol involves a 15-second or 1-minute all-out sprint, followed by blood lactate concentration sampling at intervals

• More accessible, but still needs equipment to measure lactate

3. VLamax Calculators 

• Use your power data from efforts of varying lengths to model VLamax

• Less invasive, but results can vary depending on input quality

VLamax Results Explained

So, what counts as high or low VLamax?

Remember: Higher isn’t always better. The “right” VLamax depends on your sport and goals.

Limitations and Reliability

Like any performance metric, VLamax isn’t flawless. Here’s what to keep in mind:

• Testing variability: Results depend on effort quality, pacing, and lactate measurement timing

• Individual differences: Two athletes with the same VLamax may perform differently due to muscle fibre type, training history, or VO2 max

• Not widely accessible: Lab testing can be expensive, and calculators rely on good data input

• Context matters: VLamax is most powerful when combined with VO2 max, FTP, and race demands, not as a standalone metric

‘V⁢Lamax is a relevant indicator of maximal glycolytic rate. However, this metric provides minimal extra information over using the power output from the isokinetic test alone. Practitioners may simply measure power over glycolytically demanding efforts to understand the maximal glycolytic rate of their athletes’  

- Clark, B., & Macdermid, P. W. (2025). VLamax Correlates Strongly With Glycolytic Performance. Research Quarterly for Exercise and Sport

Use VLamax as a guide, not a gospel. It helps fine-tune training, but your real progress shows up in performance on the road, track, or trail.

How to Use VLamax in Training

Once you know your VLamax, you can start tailoring your training sessions. Think of it as your metabolic fingerprint - it tells you how your body produces energy and where your training focus should be.

If your VLamax is high: You’re explosive but burn through glycogen fast. Training should shift towards endurance, threshold work, and longer steady sessions.

If your VLamax is low: You’re efficient but may lack top-end punch. Training methods should include sprints, VO2 max intervals, and strength work to boost glycolytic power.

How to Lower VLamax

A reduced VLamax is ideal for endurance athletes who need to save glycogen and rely more on fat metabolism. To bring it down try:

• Endurance rides: Long, steady Zone 2 sessions to improve aerobic efficiency

• Sweet spot / threshold intervals: Train your body to hold high output without relying heavily on glycolysis

• Fasted workouts and rides (cautiously): Occasionally riding with low glycogen can encourage fat adaptation

• Reduce sprint work: Limit high-intensity, short-burst training if your aim is pure endurance

Result: A more efficient energy system that helps you last longer at race pace.

Clothing pairing: Gear from our lightweight Distance cycling range is ideal for long endurance rides. Try the Distance cycling bib shorts to test out our no-chafe range.

How to Increase Vlamax?

If you need more sprint power, you’ll want to push VLamax higher. Here’s how:

• Sprint training: 10–15 second all-out sprints with long recovery

• Strength training:  Gym work like squats and lunges

• High-intensity intervals: Short, sharp efforts at >120% FTP with plenty of rest

Result: The power to speed up when it counts.

Clothing pairing: Our super lightweight and breathable Contest running range is built for your big push days. Try the Contest singlet for that barely there feel. 

VLamax and Running

Runners face a balance between explosive power and efficiency.

Sprinters and middle-distance runners benefit from a higher VLamax to fuel speed and anaerobic power bursts. While marathoners and ultrarunners perform better with a lower VLamax, as it delays glycogen depletion and improves fat use.

Takeaway: 400m intervals or hill sprints will raise VLamax, while long, steady runs will help lower it.

VLamax and Cycling 

Cyclists can fine-tune VLamax depending on discipline:

• Road sprinters and speed racers: Need a higher VLamax for peak power. Focus on sprints, gym strength, and VO2 max intervals

• Climbers and time trialists: Perform best with a moderate VLamax, balancing punch with efficiency. Train across the spectrum

• Ironman / endurance cyclists: Thrive on a low VLamax. Prioritise long endurance rides, threshold work, and limit sprint sessions

Performance Clothing: The Overlooked Training Edge

Fine-tuning your training program isn’t the only way to boost performance. Gear matters too. Just like the right training zones shape your fitness, the right clothing supports your body during key sessions.

• Moisture management: Technical fabrics wick sweat to keep you dry during intense intervals

• Thermoregulation: Lightweight layers help maintain consistent body temperature

• Compression & support: Bib shorts protect and improve comfort for longer sessions

Think of performance clothing as the final 1%. It won’t replace training, but it ensures every watt and every stride is used efficiently.

FAQs about VLamax Training

• How is Vlamax calculated? Through lab testing, lactate sampling, or modelling software after sprint protocols.

• What is a high VLamax? Generally >0.6 mmol/l/s. Great for sprinters, less ideal for endurance athletes.

• What’s the difference between VLamax vs VO2max? VO2 max is the maximum amount of oxygen your body can consume during exercise. VO2 max sets the upper limit of your aerobic system, while VLamax defines the lower limit of your anaerobic threshold. Together they shape performance potential.