Your lactate threshold, or your anaerobic ability, is a very useful piece of information. It allows you to know exactly how hard you can train or compete before you will begin to accumulate lactic acid in your muscles faster than they can remove it. When you are at this stage you are within minutes of having to slow down or stop. However by training just below this threshold you can ensure that you are going at the highest intensity you can sustain for prolonged periods of time.
There are many ways to test your lactate threshold. Most of these tests are complicated and require either a lot of equipment and/or a professional. There is a basic test you can do however which provides a fairly accurate estimate of your threshold heart rate.
To do this test all you will need is a heart rate monitor, a piece of paper and a pen. Apart from that you just need the equipment for whatever discipline you have decided to use. If you are jogging then you just need trainers, if you are using the rowing machine then you will need a rowing machine etc.
Put on the heart rate monitor and spend 5 to 10 minutes at a slow speed to raise your heart rate and the blood flow and temperature in your muscles. When you feel sufficiently warm you need to increase the speed or difficulty to a level that you think you can only maintain for 20 minutes. Every minute within that 20 record your heart rate. When the time is up spend 5 to 10 minutes bringing your heart rate back down.
Next you need to add together all of the heart rates you recorded during the 20 minutes. Then divide the result by 20. This is your lactate threshold, or a close estimate. So what do you do now that you have this? Well if you are training then you can use your heart rate monitor to make sure that you are at or just below your threshold. This ensures that you are training at your highest maintainable intensity. If you are competing in an event that allows you to wear a heart rate monitor, such as a marathon, then knowing your lactate threshold allows you to keep your speed as high as possible without burning out. Good luck!!