"Excellence is not an act but a habit. The things you do the most are the things you will do best." -- Marva Collins
30-Minute Time Trial for Estimating Lactate Threshold
You can perform this test by running, cycling, swimming or doing any other endurance sport that can be sustained for 30 minutes. It is generally recommended that you choose an event with which you are comfortable (i.e. if you're a runner, you wouldn't try to estimate your LT by cycling).
Regardless of the type of activity, you will need a heart rate monitor and a way to capture splits.
It is imperative that you warm up for 12-15 minutes! Once warm, slowly increase the intensity, working up to your peak, sustainable intensity within the first 10 minutes.
For the next 20 minutes, you'll need to record your heart rate every minute. Once you've completed the time trial (and have cooled down properly), you'll simply calculate the average of those 20 heart rate recordings. This figure represents your estimated heart rate at lactate threshold.