Anaerobic threshold, also called the lactate threshold – is the level of your body exertion where your body must switch from using/burning energy – glucose, with enough supply of oxygen, to using/ burning energy without enough supply of oxygen.
Lactate (lactic acid) – is a byproduct of energy (glucose) use of the muscles, that stores in muscle cells and can also be traced in blood. It accumulates at higher intensity of exercise (running uphill, catching runaway buss, bicycling uphill, escaping the shark in ocean or grizzly bear in woods) where oxygen is limited.
The most common use of the term “anaerobic threshold” is to describe a phenomenon that takes place mainly in athletes – the maximal speed or effort that an athlete can maintain and still have no increase in lactate. At this speed or effort, lactate levels in the blood remain constant, at about 4 mmol/l.
Any increase in effort or speed above this level will cause lactate and its associated high acid levels to increase steadily. This will eventually force the person to slow down or stop. The time to stopping or slowing down will depend upon how far the athlete is above the maximum steady state effort, the event the athlete is competing in, the type of athlete (strength or endurance) and his cardiovascular conditioning.
The working muscle cells can continue this type of intensity with anaerobic energy production at high rates for some short period, usually 1 – 7 min., depending on intensity. During this time lactate accumulates in muscles to high levels. And you either escaped that bear, or you will have to stop and convince him that he is really not that hungry, and that raspberries taste much better than you.
Anaerobic threshold is in most individuals at 4 mmol/liter of lactate, measured in your blood. This measurement is done by doctor or nurse pinching your finger or ear with tiny needle and taking small amount of blood sample to measure the lactate at certain intensities (speed and heart rate), while you are still running on treadmill, rowing on rowing machine, or bicycling on stationary bike.
I remember going from my VO2 max testings with sore fingers, because they were all pinched by a little needle for taking a blood sample. It usually didn’t hurt at all, mainly because the pain from the intensity on rowing machine I was on was much higher.
Anaerobic threshold is the state of the body, where certain amount of lactic acid is already deposited into your muscles, but you can still keep the intensity and supply enough oxygen to prevent lactic acid build up.
Generally the higher the levels of VO2 max of a person the higher the anaerobic threshold is.
Anaerobic threshold in practice
When you run on the treadmill and start slowly increasing your speed until your lactate reaches about 4 mmol/l, and lets say your speed will be 6.3 miles per hour at this state, you will be able to keep going as long as you want at this intensity. You are just at or slightly below your own anaerobic threshold.
Of course, eventually your back will start hurting, or you will need to visit a bathroom, or run out of energy and you will have to stop. But unless you increase the intensity, you will be burning energy mainly aerobically with oxygen and that means no further lactic acid accumulation.
Now let’s say, that you increase the speed on the treadmill to 6.5 miles per hour and keep running. You will be able to still continue running for extended time, but your lactate will slowly build up in your blood and muscles and finally reaches the point when you have to stop. Let’s say, this happens 10 minutes later.
If you increase speed on the treadmill even higher, from 6.3 miles per hour to 6.7, the lactate will build up in you blood stream much faster and you will have to stop much sooner. Probably in 5 minutes of so.
From this example, your anaerobic threshold will be at around running speed of 6.2-6.3 miles per hour.
This information is very important if you are an athlete and you are trying to increase your VO2 max, and generally your aerobic capacity.
It is important, because training at anaerobic threshold level, or just a little bit below it shows to be the most effective way to increase VO2 max.
So if my anaerobic threshold shows on concept2 rowing machine to be at the speed of 1:45 min per 500 meters, I will try to apply this information in my training. And that would be: Doing few of my training sessions on the water in this particular speed for extended period of time.
To measure this speed, we all had a speedometer in front of us. It is a little monitor that’s connected to the boat with a little propeller under water that measures your speed.
But of course this system has it’s flaws. The monitors don’t know if you are rowing downstream or upstream, or if wind blows into your face or into your back. And constant adjustment is necessary.
Experienced athletes know by just how they feel, if they reached or are close to their own anaerobic threshold. It’s a feeling that’s very uncomfortable, but they still can endure it for a long time. They can apply anaerobic threshold workout sessions without any monitors very successfully.
High anaerobic threshold means better aerobic performance
If we go for a run together and we will run at the pace of 6.5 miles per hour and your anaerobic threshold/ lactate threshold is at 6.7 miles per hour and mine is at 6.3 miles per hour, you will be just cruising, happily smiling and easily leading conversation with me. And I will be barely keeping up with you, not able to say a word. You will be looking at me and thinking: what’s wrong with you buddy?
That’s exactly what athletes are trying to achieve. They are training to increase their anaerobic threshold, so they can be the one just cruising and winning, and their opponents suffering and loosing.
Having a high lactate threshold and high VO2 max levels is a fantastic thing to have if you are a competitive endurance athlete. And if you have it higher than everybody else in your chosen sport, shelves at your home are going to be filled with a lot of trophies, for winning your races.
Lance Armstrong isn’t really suffering more than anybody else on the road as many of us might think. He is actually suffering much less and that’s why he is winning his races.
He has high VO2 max and high anaerobic threshold and that means less suffering and more winning. Just try to do what he does in 1/2 of his speed. You will suffer the most of all and you’ll probably end up finishing your Tour the France stage last.
The main goal for an endurance athlete is to push his anaerobic threshold higher. And higher your VO2 max levels are the higher your anaerobic threshold is at your specific aerobic activity, eater it is running, swimming or rowing.
How do you increase you anaerobic threshold (lactate threshold)?
Like I wrote before: The higher the VO2 max of the person is, the higher his anaerobic threshold is too. That’s why, training plan for maximization of VO2 max level is the most effective way to increase anaerobic threshold.
And that training plan consists of sensitive placements of different endurance kinds of training sessions, like: interval training sessions, anaerobic threshold level long uninterrupted distance endurance training sessions, and long, less intensive uninterrupted long distance endurance sessions.