Lactate threshold test

Blood, sweat and gears at Bristol Bike Lab

We recently visited Bristol Bike Lab to learn about blood lactate and power based performance testing. The only way we could really get an idea of what is involved, was to put our fittest rider forward for the test, Jamie. He was put through the paces by Ben, while we learnt about the process and what it takes to get the results.

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In animals, L-lactate is constantly produced from pyruvate via the enzyme lactate dehydrogenase (LDH) in a process of fermentation during normal metabolism and exercise – pure science. It does not increase in concentration until the rate of lactate production exceeds the rate of lactate removal. Which is commonly referred to as the burn, it’s where your body can not stay above for too long without rapidly reaching exhaustion. The lactate threshold!

So what is lactate and why does it matter to cyclists?

Basically, the threshold, is the exercise intensity at which the blood concentration of lactate and/or lactic acid begins to exponentially increase (the burn). Often expressed as 85% of maximum heart rate or 75% of maximum oxygen intake. When exercising at or below the lactate threshold, any lactate produced by the muscles is removed by the body without it building up. So to be able to raise your lactate threshold level will mean you can ride further or faster or both.

Why do the Lactate threshold test?

This test is of value for any type of competitive or endurance cyclist. The test that Bristol Bike Lab have conceived is based on a ramp test, gaining in power output at each ramp (timed stages of three minutes). It will always start at an agreed watts output and will ramp up from there. How many ramps depends on the rider but, each ramp is going to jump up in power output (25watt increments) until you reach your maximum (to exhaustion and stop the test). This is done using your bike on a Wahoo kickr. The best part of the ramp test is not needing to think about it, each ramp is controlled by Ben, who is the owner and tester of Bristol Bike Lab, on the iPad, all you have to do is suffer! The process of the test could not be more simple for the rider, if not painful towards the end but, hey you know that.

lactate threshold test

At each ramp a lactate reading is taken. Ben will take that reading with a device similar to those used by diabetics but is reading your lactate. It basically involves a pin prick to the finger and measure taken on the device to read how much lactate is in your blood. This is measured in mmol/L of lactate – mmol/L is a commonly used unit used in chemistry. These measurements are plotted against the power output to give you a chart that allows Ben to read and interpret how best for you to train to either reach your specific goal or how you can generally improve performance.

Ben’s background is in mountain biking and coaching athletes who are looking to do well at racing in endurance based mtb races. He has been doing this for many years and works with a lot of high-calibre riders. This background and knowledge have led him to offer the lactate threshold test for road riders as well as mtb riders.


So what’s it like to do the lactate threshold test?

When you arrive Ben will assess you for the test and get you and your bike set-up. He will explain what’s going to happen and what is expected of the test. This kind of test will take around and hour to perform.

Ben believes that the lactate threshold test is great for road riders, as it’s often about power outputs, and if your need a specific number to reach. To win or get a certain time you’re aiming for then you need to know you can physically produce that number by means of testing, training and re-testing. This test is the best way to achieve your results, no guessing, just testing and hard work.

Once you’re set-up, the test explained, the work begins. Warming up for 10-15mins at 100watts. At which point your first blood reading is taken, after this at each ramp a sample will be taken. This will be plotted against your power. Alongside this your heart rate is recorded on your own device which Ben will monitor on his desk, you see nothing, just feel the exertion. Once you reach exhaustion the test stops and all the data compiled is analysed by Ben. This is where his years of experience and research pay off. What you get is a concise report on where you need to improve and it’s as simple as that but, what you have is an excellent tool to work with.

lactate threshold test

lactate threshold test

So the guess work has gone, you have a good set of data to work to. Improvement with the required work is guaranteed. This is very valuable to any road rider looking to beat a PB.

So if you’re looking to improve, no matter the level you’re currently at, the lactate threshold test performed by Bristol Bike Lab is going to get you great results. For further information visit

We also have an exclusive offer for Headset Press readers. Simply enter the code hspress-20 at the checkout and you will receive £20 off of a blood lactate test.  Offer valid until 24th December, however bookings can be made for up to 6 months in advance.

A big thank you to Ben at Bristol Bike Lab for showing us the lactate threshold test.

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