If you’ve participated in endurance sports in the past, lactate threshold is probably a term you’ve heard before. It is widely used in endurance sports as way of determining training intensity. In CrossFit it isn’t as widely used with people preferring the go hard or go home method of training. Whilst this is fine if your training is relatively low volume, as you get more serious as a CrossFit athlete and your training volume increases this isn’t necessarily the best way to go. Besides the accumulation of fatigue, there are also physiological adaptations that don’t occur when you go all out all the time, which are beneficial to improving your fitness capabilities.
At this point let me explain what lactate threshold is. There are three different terms you need to be familiar with and many different terms to explain essentially the same thing. Your lactate threshold is the point at which your blood lactate rises 1 mmol/l above your resting blood lactate levels. This point may also be referred to as the onset of blood lactate accumulation (OBLA) or your lactate turn point 1 and fuel dependant you should be able to maintain this level of intensity indefinitely.
Your maximal lactate steady state is a happy medium where your blood lactate is elevated but your body can buffer or remove the lactate at an equal rate, you can generally maintain this level of intensity for up to 90 minutes depending on your glycogen stores.
Finally, your lactate turn point is the point at which lactate production exceeds lactate removal. How long you can maintain this level of intensity depends on your bodies ability to tolerate the decrease in PH and the associated decline in muscle function, and how willing you are to tolerate the pain! This point is sometimes also referred to as lactate turn point 2. These three different levels of intensity are illustrated in the graph below.
Finding your lactate threshold, maximal lactate steady state and lactate turn point are ideally done in a lab setting, on either a rower, bike or treadmill depending on your sport, using blood sampling. Whilst we can do this easily enough, it involves you travelling to us which with remote clients isn’t the most practical. What we can do instead is gym based testing, and with CrossFit being a multidimensional sport we can do it on as many different pieces of equipment as you have available to you. This information, combined with your heart rate data from the tests will allow us to prescribe specific work intensities for each piece of equipment, as well as amalgamate the data to get a good idea of your training zones when we put you into a mixed modality workout aka CrossFit. Once we have this data, we can use it in your training programme to allow us to manipulate the intensity of your workouts to get the adaptations we are after.
As mentioned previously those adaptations are different depending on the zone of intensity you are working at. In zone 1, around your lactate threshold, the primary adaptations are increased glycogen storage and improved utilisation of both fat and glycogen as a fuel source. In zone 2, around your maximal lactate steady state, the main adaptations are improved metabolic efficiency, improved lactate clearance, an increase in capillarisation of muscle fibres and an increase in aerobic enzymes. The main adaptations that occur at or above your lactate turn point are improved lactate clearance, as well as an improved ability to tolerate acidosis – the decrease in Ph that occurs as muscle and blood lactate increases. Once we can identify where each point is for you, then we can tell you how hard you need to be working in each zone, so we can make sure your training covers the whole range of adaptations, making you as fit as possible.
This information is also useful when it comes to the time around competition or your periodic deload weeks. Knowing where these zones lie for you can allow us more specifically to determine what really is recovery pace for you, so when it comes to tapering and making sure your ready to compete we can do this as accurately as possible.
In the next post we will discuss what your training may look like in each of these zones, the different approaches to training distribution and how we periodise it over the course of a season.