science for coachingThe lactate threshold is generally regarded as THE measure of endurance fitness by physiologists

The lactate threshold, or "LT" occurs at about 60% of your VO2max (or a steady pace you could hold for ~4 / 5 hour ). It is the highest intensity at which blood lactate remains at baseline levels. Any higher than this intensity, and the rate at which you generate lactic acid in the muscle outstrips the capacity at which it can be metabolized - the excess appears as elevated blood lactate. This makes LT a really useful marker as a training zone boundary  for your steady training 'base miles'. You can read more about the physiology of training in this area in the following factsheets from our library: the Determinants of endurance performance, The physiological basis of the training zones and Pushing and pulling.

LT is measured in the lab by slowly increasing intensity and taking a series of small fingertip blood samples at the end of each stage. Typically, each stage is 3 to 4 minutes - just long enough to let your body reach a steady state. We also record heart rate and power output throughout the test so that we can provide you with your training zones. Typically we will run a lactate threshold test in tandem with a VO2max test. This gives a broad sweep of your endurance physiology from low intensity up to your maximum aerobic capacity.

PBscience athletes receive LT testing:Lactate Threshold

We also offer lab testing for non-members - please email Dan for prices and availability.

Watch our video of a lactate threshold test to learn more about what's involved