What is the best method for estimating Lactate Threshold in the field?

These days there are many runners and triathletes who use tests that estimate lactate threshold as a means to predict heart rate and/or running velocity at the lactate threshold for training and racing purposes. This is particularly common in athletes with Internet coaches where an estimation of heart rate at the threshold was used to provide training recommendations when coupled with the use of heart-rate monitors.

The lactate threshold has been used to compare performance capability between distance runners and/or to monitor performance capability in an individual over time due to its strong relationship with distance-running performance. In a recent study various methods were compared for estimating lactate threshold in the field. Each method was compared to a VO2 test taken with lactate samples during the test in a laboratory, this is widely known as the "Gold Standard" of measurements. These tests chosen for their popularity and ease to implement in the field.In the study "A Comparison Of Methods For Estimating The Lactate Threshold" they compared 4 methods that are highly used in the field.

What is Lactate Threshold?
Lactate Threshold (LT) is a by-product of anaerobic metabolism that, despite common misconception, is produced across all exercise intensities. At a given exercise intensity, blood-lactate concentration rises exponentially; as heart rate plateaus and blood-lactate concentration continuous to increase this deflection point is commonly known as the lactate threshold, beyond this point is known as acidosis.

Glucose + ADP -> lactic acid + ATP

Why do we measure it?
To quantify and keep track of our efforts in training/racing.

A Comparison of Methods for Estimating the Lactate Threshold
J Strength Cond Res. 2005 Aug;19(3):553-8

The 4 tests were: VDot method (1), 3200 meter time trial (2), 30 minute time trial (3), Conconi test (4)

The results were that the ability to measure lactate threshold differed according to the estimation used. Heart rate at lactate threshold was found fairly accurately using the 30-min time trial and Conconi methods. The 30-min time trial also accurately estimated running velocity at the lactate threshold. Due to its simplicity, ease to obtain heart rate and running velocity at threshold, ease in interpreting the results, and minimal equipment needed, they concluded that the 30-min time trial method should be considered by athletes/coaches when estimating lactate threshold in an attempt to optimize run training and performance.

**All test were done on a treadmill to avoid any effect from environmental conditions, these test can be easily reproduced on a track or on a known distance**

1. Daniels J. Daniels running formula. Chicago: Human Kinetics, 1998

2. Weltman, A. Prediction of lactate threshold and fixed blood lactate concentrations from 3200-m running performance in male runners. Int. J. Sports Med. 8:401-406 1987.

3. Friel, J. The athlete as a scientist. Inside Triathlon 15:52-53. 2000

4. Conconi, F. The conconi test: Medthodology after 12 years of application. Int. J. Sports Med. 17:509-519. 1996