Have you ever wondered why during or after a workout you feel like your muscles are aching or burning? Why you cannot catch your breath to save your life? The answer is a phenomenon called Lactic Acid.
The body has two main ways of producing energy: the Aerobic and Anaerobic systems. The aerobic system uses oxygen to produce energy and is used for longer time period events such as a 5k run or rowing. The anaerobic energy system uses phosphocreatine and glycogen to fuel the body for events that are short and intermediate such as a one rep squat or intervals.
In order to talk about the lactate threshold it is important to first understand these energy systems. As people exercise lactic acid in the blood increases due to the intensity that is being stressed on the body. The lactate is released by the muscle cell in order for the body to convert it into glucose in the liver for the body to continue to produce energy. Glucose that is produced from lactic acid is important for the body because the body will use that glucose to produce energy and that energy in turn will fuel your body to continue to exercise or work harder. When the intensity increases and the lactate is being released too quickly for the body to convert it we hit our lactate threshold. This is the stage where your muscles are burning or aching, and your performance will decrease quickly or more cause you to stop the activity to recover.
Why is lactate threshold relevant to me?
Some people may be wondering why hitting the lactate threshold may be important to them. As high intensity workouts such as a Crossfit WOD (Workout Of the Day) are done, your body is producing high amounts of lactic acid. This isn’t a bad thing, it is simply how the body responses to the stimulus. This is actually very good for your body! Why you ask? Because as you continually train, and lactate is regularly being released into your system, your body will learn to convert the lactic acid back into glucose faster and faster for your body to use for your training session.
This is huge because as the conversion gets faster and faster, your performance level and lactate threshold go up. During 16.1 (20 min AMRAP Walking lunges, burpees, chest to bars) you were probably feeling a burning sensation in your legs later in the workout, but it was important to continue to work in order to better your scores. This in turn helped your body push the lactate threshold that it was accustomed too. Just by pushing the limit to a tolerable end your lactate threshold will increase and you will see differences in performance and recovery.