Continuous Lactate Monitors for athletes – explained

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A continuous lactate monitor (CLM) enables athletes to get real time information about key performance metabolites during training. This article covers practical examples of how a CLM can be used to optimise performance. We also talk about all (soon to be available) continuous lactate monitors on the market.

Lactate measurements are commonly used during performance lab tests. It gives valuable information about how an athlete responds to exercise. However, lab tests are a snapshot. That’s why professional athletes started taking lactate measurements regularly during training. The continuous lactate monitor will revolutionise this by enabling athletes and coaches to get real time feedback on their smartwatch or bike computer.

Watch the video to get an introduction to continuous lactate monitoring:

Jump straight to:

What is a continuous lactate monitor (CLM)

A continuous lactate monitor (CLM) is a wearable sensor that measures lactate concentrations in the body during exercise. This monitor can be implemented in health care situations, but this article focuses on the fitness benefits for athletes.

Lactate monitors have been around for ages. Athletes prick their finger or earlobe to take a blood sample and analyse it with a lactate strip and a (handheld) lactate monitor. The lactate monitor shows the blood lactate concentration in mmol/L during exercise.

“Lactate testing is probably the best way to assess muscle metabolic stress and performance, especially in endurance athletes.”

Iñigo San Millán, head of performance at UAE Team Emirates.


The data – which we’ll talk about in a second – can be super interesting. However, the process is time consuming and interruptive. Hence the need for a continuous lactate sensor, very similar to a continuous glucose monitor.

Benefits of continuous lactate monitoring

The obvious benefit of continuous lactate monitors vs traditional lactate monitors is twofold:

  1. You get a continuous data stream which enables you to detect upward and downward lactate trends much better.
  2. Continuous lactate monitors are more time efficient and less interruptive than repeated blood lactate sampling.

But why do athletes need to monitor lactate levels in the first place?

K'Watch continuous lactate monitor device from PKvitality
K’Watch continuous lactate wearable (source: PKvitality)

Why monitoring lactate during exercise is important

Athletes should monitor their lactate levels during exercise, because lactate concentrations are a great way to determine exercise intensity and predict fatigue. But there’s more:

  • The highest intensity at which lactate concentrations remain in steady state (no increase) determines your anaerobic threshold.
  • An increase in lactate concentrations is a good marker for acute fatigue.
  • A decrease in lactate concentrations is a good marker for acute recovery.
  • Whenever you burn a carbohydrate (glucose or glycogen) during glycolysis, lactate is the end product. Therefore, lactate concentrations tell you something about the fuel (fat vs carbs) used during exercise.
  • Lactate is mainly produced in fast twitch muscle fibers and used as a fuel in slow twitch muscle fibers. Therefore, lactate concentrations tell you something about muscle fiber type recruitment.

In the next section we’re going to look at practical examples of how to use this information in training and racing.

“Biosensors are the future. We should be able to measure different metabolites key to performance in real-time and have them displayed in your bike computer.”

San Millán, collaborating on a lactate biosensor project right now.


How to use a CLM in training and racing

This brings us to practical ways you can use a continuous lactate monitor in training and racing. Here are some examples.

Train at LT1 (aerobic threshold)

Lactate threshold 1 (LT1) is an exercise intensity often used for long endurance training. At this exercise intensity, you mainly use fat as a fuel. Slow twitch muscle fibers (e.g. type I) are dominant.

Many athletes tend to go too fast during their LT1 training. Use your continuous lactate monitor to make sure your intensity does not increase above LT1. A lactate concentration of 2.0 mmol/l is often used as a LT1 marker.

Learn more about this topic in my LT1 ultimate guide (link to external site).

Apply the Norwegian Training Method

The best triathletes are making incredible training progress with the Norwegian Training Method. This method is famous for its repeated lactate monitoring during training.

Taking lactate measurements is nothing new – but without a continuous lactate monitor, it’s time consuming and interrupting training.

Use your continuous lactate monitor to do their famous (sub)threshold training. Make sure your lactate concentration remains in steady state during the threshold intervals. Note: threshold intensity does not necessarily equal a lactate concentration of 4 mmol/l.

Learn more about this training method in my Practical Guide on how to implement the Norwegian Training Method (link to external site).

Continuous lactate monitoring for interval training

Take interval training to a higher level, using a CLM. Continuously monitor changes in lactate concentrations and use them as a marker for fatigue and recovery. For example: recover until lactate concentrations are back to e.g. 2.5 mmol/l.

You can also do long intervals at (very) high lactate concentrations. Here’s how: first pre-load your interval with a high intensity interval that increases lactate concentration to e.g. 7 mmol/l. Then continue for several minutes at threshold intensity, using the continuous lactate monitor to make sure the concentration remains at 7 mmol/l.

Use a CLM to burn the most fat during exercise

Lactate is the preferred fuel over fat. In other words: the higher the lactate concentration, the less fat you burn.

Use your CLM to keep lactate levels low, while aiming for a relatively high exercise intensity to burn the most calories. Get more tips about burning the most fat during exercise.

Continuous lactate monitor devices

There are several companies competing to be the first to launch a CLM on the market. Interestingly, they are using different types (measurement methods) of continuous lactate meters. The first continuous lactate biosensor will be launched in April 2024…

Here’s an overview of (soon to be) available continuous lactate monitoring devices:

IDRO continuous lactate patch

The Belgium company IDRO has a working real-time lactate sensing smart patch. It measures lactate levels from sweat, and relies on an enzyme-based sensor.

Their CLM sensor also measures pH and skin temperature. Readings are streamed to your smartphone via bluetooth.

IDRO aims to launch their product in April 2024. Contrary to other companies, this goal seems very realistic, given the fact that the lactate patch is already used in scientific research and product demos.

IDRO continuous lactate monitor device based on sweat analysis
IDRO continuous lactate monitor device based on sweat analysis (source: IDRO Instagram)

In the research, the sweat measurements of the IDRO device were compared with gold standard lactate measurements. A good correlation between both measurements was found (R² = 0,95) with a difference ranging from 2 to 11%.

IDRO continuous lactate measurements via sweat vs blood
IDRO continuous lactate measurements in sweat vs blood (source: IDRO Instagram)

Initially, IDRO will focus on providing their product to performance test centers and coaches. Afterwards they want to make their CLM available for all athletes.

Unfortunately, they were not yet able to communicate how much this continuous lactate monitor will cost. To get an idea of CLM pricing, we need to look at one of their competitors:

K’Watch continuous lactate watch

The French company PK Vitality announced that their K’Watch continuous lactate device will be available in 2024. It’s a wearable CLM, worn as an armband or watch.

K'Watch continuous lactate wearable
K’Watch continuous lactate wearable (source: PKvitality)

The sensor measures lactate levels when in contact with the skin, without blood samples. This makes it a pain free monitor. The “SkinTaste technology” sensor measures lactate in the interstitial fluid (between blood vessels and cells). The sensor should be replaced every 30 days.

Pricing? This K’Watch continuous lactate monitor costs $199. The sensor costs an additional $90.90 per month. It will be available as soon as medical certification is being passed.

Abbott – Lingo

Contrary to the other two companies, Abbott is a company you may have heard of already. The Abbott libre sense glucose sensor is the sensor used by Supersapiens for continuous glucose monitoring.

Supersapiens Abbott continuous glucose semsor
Abbott libre sense glucose sensor, used by Supersapiens for continuous glucose monitoring.

During the Consumer Electronic Show (CES) 2022, Abbott launched their plans for a metabolic profile coach, Lingo. Lingo will continuously measure: glucose, lactate, ketone and alcohol. Watch the 5 minute presentation about Lingo here:

Rumours suggest Abbott will launch their lactate tracking system and app this year (2024). However, during the WIRED Health event in March 2023 Abbott repeatedly referred to 2028 in phrases like:

“In 2028, you may wake up to an app giving you personalized recommendations (…) We’re not there quite yet, but it’s not far off.” – Marc Taub (Abbott) in March 2023.

Regardless of when they will make their continuous lactate monitor available, it will probably be a huge competitor for all other companies.

Their existing continuous glucose sensor is a minimal invasive sensor, measuring glucose just underneath the skin. You need to replace the sensor every 14 days, but applying the sensor is painless. This biosensor costs roughly €160 per month, depending on your Supersapiens plan.

Conclusion: are CLMs worth it?

Continuous lactate monitors are about to enter the market. Professional coaches and athletes say it will revolutionize athletic performance.

I personally believe CLMs indeed have the potential to join fundamental sensors like heart rate monitors and power meters. Contrary to continuous glucose monitors, I believe CLMs will be implemented and embraced much faster. That is due to the fact that many coaches and athletes already know what to do with lactate data.

For those who are interested in CLMs, I suggest not to wait for them. You can already experiment with taking “traditional” lactate measurements during training, for example when running or cycling indoors. This will give you a huge head start once CLMs are available.

I’d love to hear your opinion on CLMs. Will you buy one? Or do you think it’s just another hype? Let me know via social media (links below) or email!