Our previous Lactate article (here) described what lactate is, how it is used and common misconceptions surrounding the molecule.

This article explains why it could be beneficial to understand the levels of lactate your body produces to make your training more efficient

Here’s a reminder of a lactate curve:

Graph showing HR and lactate responding to intensity

Could I do with knowing my lactate curve?


Yes, as long as you are not trying to identify your curve using limited values.

Alongside testing for your VO2Max, testing for your lactate curve can be an effective measure of training effectiveness, when the test is done correctly to look at the relevant points FOR YOU. Ultimately, we all want to perform well in races and events, and these are our most important “measures” but, if you have access to the science, then lactate testing can certainly be a useful tool to take from your training toolbox.

What is the testing procedure?

Usually a lactate test takes the form of a “ramp” test. This involves increasing your exercise intensity over time.

Here are the main points to ensure you obtain beneficial lactate results that you can use to either construct your training plan (based on your training approach) and/or measure your sub-maximal fitness:

1. Ensure incremental stages are long enough to accommodate for any “lag” in the rise of lactate within the blood. We recommend 4-5 minute stages.

2. Ensure the exercise done in the test matches the exercise you are trying to improve or compete in i.e. don’t do the test on the bike if you are solely a runner!

3. Do the test more than once. Ideally repeat exactly the same test after a block of training, under the same conditions. This will show whether there has been a change and improvement in response to your training.

4. Make sure the testing is done using reliable equipment. Each blood sample taken (usually from a finger-prick) is applied to a new testing strip. Testing strips should not be out of date because this can lead to hugely inaccurate results. Reliable testing kits are available for anyone to purchase, just make sure you follow a reliable procedure if you go down this route.

5. A tester should follow a rough protocol of testing every 4-5 minutes until he or she deems all the relevant points have been identified. However, a good tester will have some degree of flexibility e.g. making the call to increase the intensity in smaller time windows because of previous results and trends.

6. Don’t assume that your lactate levels remain static between time periods with everything else remaining equal. Testing on one day may give different results to the following day. For this reason, when you come to re-test, try to follow the same routine in the build up to the first test e.g. rest the day before testing and do the test at the same time of day.


To get a more accurate reading of one’s MLSS, the testing procedure can be done over a week or so. Following the ramp test you may be asked to do recurring 30 minute bouts of exercise (with days recovery between each) at intensities just above, just below and/or right at your predicted MLSS from the ramp test. The data following this procedure is more accurate but the downside is that it can disrupt your training (as well as being quite uncomfortable!)

Is a lactate test beneficial for me?

For the sake of ease, let’s assume we have access to a valid lactate testing procedure and we are using this lactate test to determine our Maximum Lactate Steady State (MLSS) – an important level among endurance athletes because we’re assuming that this is the level of intensity that can be sustained for a long(ish) time, of around 1 hour in duration. When compared to other points on the lactate curve, MLSS is the favoured approach for useful exercise thresholds and subsequently important for training interventions. If this threshold can be increased through a training block then you should, in theory, be able to sustain a higher intensity (e.g. running speed or bike power) for the same length of time following the block.

Also, in events that last over 1 hour where lactate levels on average remain very low, there will still be periods when lactate levels rise and recover (e.g. cycling hard up a steep hill to get away from a rival in a stage race or coming to a steep incline in an ultra distance run). You therefore have to be able to cope with higher levels of lactate and also be able to metabolise the lactate as fuel during periods of lower intensity (e.g. the downhills!) Most endurance events vary in intensity to some extent.

We can therefore suggest that lactate testing is a good measure of sub-maximal fitness even if you are competing in events that are, on average, not surpassing the MLSS and/or the majority of other lactate thresholds tested.

How can I train to increase my MLSS?

Like with VO2Max intensity, it’s not essential for everyone to train at the MLSS intensity level in order to improve it. The intensity to train at to improve one’s VO2Max or MLSS is hotly debated and highly individual.

Although this article mentions MLSS a lot, don’t become too obsessed with it as a frequent level of training intensity. It is inconclusive as to whether the MLSS can be improved by training “at it“, “a little bit below it” or “a little bit above it“. For example, if you determine your MLSS (remember this is threshold often used interchangeably with Functional Threshold Power) to occur at a power output of 300 watts, then there isn’t significant evidence to suggest that training at 90% (270watts), 100% (300 watts) or 110% (330 watts) will be most beneficial.

Long, slow distance (LSD) and High Intensity Interval Training (HIIT) both have benefits relating to the lactate curve but, like with most things in training and racing, it still comes down to the aspects of specificity and individuality. These aspects include the event you are racing, your training level, your training history, your body composition, your conditioning (bone, tendon and ligament adaptations) , your injury status…….the list goes on and on…….


There is no definitive answer as to whether knowing your lactate curve can have a beneficial effect on your training and racing. We test lactate levels frequently at Optimal Movement and some would argue I should be making a “harder sell”! Like with any metric though, it depends on how you use it and how much you let it take over your training (and life!) As a coach of endurance runners, cyclists and triathletes, to me it is very beneficial to test and re-test the lactate curve. We can certainly improve the effectiveness of someone’s training when testing is used in the right way. It’s just important to remember that lactate is simply one component of an effective, multi-factorial training plan.

From experience, we have seen various lactate thresholds improve through a variety of training approaches depending on the individual. It’s therefore important to approach lactate testing in a long-term and flexible way, not becoming too obsessed on specific numbers (like the intensity at which you reach 4mmols of lactate in your blood for example).

Use the test and resulting lactate levels as a measure of individual fitness and an extra tool in your training toolbox. If you are interested in discussing whether it would be useful to you and your training then please get in touch.