LACTATE THRESHOLD

Post date: Jan 6, 2015 6:14:14 PM

Lactate Threshold

Understanding anaerobic threshold will make you a better endurance athlete. If your VO2max is your aerobic potential, your anaerobic threshold determines how much of that potential you tap. More importantly you can improve your lactate threshold considerably with athletic training...

If you haven't already, read the article on VO2max before you read on. If you have, here's a quick recap... 

VO2max is the point at which your body cannot increase its intake of oxygendespite an increase in exercise intensity. Exercise beyond this point has to be anaerobic (without oxygen). The result?... 

High levels of blood lactate that puts a halt to your progress. Does that mean then if you exercise at an intensity below your VO2max you'll be able to continue indefinitely? Not really... 

For most people debilitating blood lactate starts to accumulate at an exercise intensity much lower than at VO2max. At rest and during gentle exercise the body still produces lactate, however it can remove it just as quickly. Hence no lactate builds up. 

As the exercise intensity increases and anaerobic pathways are called upon more and more, the body struggles to remove lactate as quickly as it's produced. Hence blood lactate begins to accumulate. The point at which this occurs is called your... 

Anaerobic threshold.

Technically speaking there's controversy over the term 'anaerobic threshold'. As a result a whole host of terms have formed to describe essentially the same phenomenon. You may have heard of some of them... 

• Expiratory compensation threshold

and so on... 

We'll stick to anaerobic threshold for simplicity's sake. After all... 

To improve your endurance performance doesn't require an intricate understanding and appreciation of every technicality! 

Just like VO2max, anaerobic threshold occurs at different exercise intensities for different people. It is expressed as a percentage of your VO2max. Imagine the graph below represents you running... 

Knowing your anaerobic threshold allows you to predict with great accuracy your time in any given distance event. Better still... 

Specific endurance training (outlined below) can increase your anaerobic threshold significantly. The average, untrained individual has an anaerobic threshold at 55-60% of their VO2max. For elite athletes anaerobic threshold occurs around 85-90% of their VO2max. How will you benefit from training? 

Training won't slow down the rate at which blood lactate accumulates but what it will do is delay it's onset until a higher exercise intensity. In short... 

You will tap more of your 'aerobic potential'. 

So how do you improve you anaerobic threshold? The first step is to find out where it lies for you... 

Eliciting Your Anaerobic Threshold

If you have access to expensive and sophisticated laboratory equipment and a skilled lab technician, testing your anaerobic threshold is simple. Assuming that you don't... 

There are a couple of alternatives worth considering. For each of them you do require a heart rate monitor. Having said that in order to improve your anaerobic threshold and your endurance a heart rate monitor is essential anyway. 

1. 10 Minute Run

Run or cycle for at least 20 minutes. Gradually increase your speed and heart rate. You will eventually reach a point where your breathing rate suddenly increases sharply and your legs feel a bit jelly like. 

Instinctively you'll know that you can't maintain a steady state any longer -- at this pace you will become more and more fatigued. Glance at your monitor and note your heart rate. Although this is quite a subjective test it can be very accurate.

2. One Hour Time Trial

This is probably the most common anaerobic threshold test used in the field. You need to be able to run or cycle at the highest intensity you can sustain for one hour. Inexperienced athletes will either start off too fast and have to slow down, or perform the entire test too slowly. Runners can substitute the one hour time trial for a 10k race. 

You should record your heart rate regularly -- ideally every 2 minutes. Average your heart rate over the hour or 10k to give you an indication of your anaerobic threshold heart rate. 

3. Conconi Test

The Conconi test is more complicated than the above two methods and not necessarily any more accurate. In fact the test has been shown to OVER-estimate the anaerobic threshold considerably in many athletes. 

Accuracy is also highly dependant on your ability to gradually increase speed smoothly and consistently. All things considered you are best using one of the other tests. 

4. Portable Lactate Analyser 

Using a portable analyser will give you the same accuracy as a lab test providing you know what you are doing. This is only worth considering if you are a serious athlete. The cost starts at around $400. For more information seehttp://www.lactate.com/

Once you have determined a heart rate that you feel corresponds to your anaerobic threshold you can start to design athletic training sessions to improve it... 

Anaerobic Threshold Training

Anaerobic threshold training is relatively straight forward once you have established your target heart rate zone. The intensity of training sessions should be at or just below your anaerobic threshold. 

Anaerobic threshold training sessions can take the form of either interval or continuous training. Interval training should consist of three to five, 6-12 minute intervals. The rest period between intervals should be 2-3 minutes. Ideally you would reach your target heart rate as quickly as possible -- inside a minute. 

A typical anaerobic threshold training session for a cyclist might be... 

* ATHR = Anaerobic Threshold Heart Rate 

A continuous training session to improve anaerobic threshold should last for 20-45 minutes. This is more demanding than the interval session so build up to it gradually. 

To wrap up... 

Anaerobic threshold is more reliable indicator of your performance than VO2max. More importantly... 

Anaerobic threshold is generally more responsive to training, especially if you are regularly active.