Throughout my career as an age group triathlete, I have always tried to approach training and racing in the most scientific way possible. Having no background at all in any sport prior to running and triathlon (2009 and 2010 respectively), I am the epitome of a late bloomer. My passion to improve motivated me to learn about the sport as much as I could. Knowing I lack the athleticism and physical prowess my competition had, I knew I had to be more intelligent with my training regimen. By approaching the sport in a more cerebral manner, I improved exponentially.
Apart from heart rate monitors and power meters, lactate testing brought the biggest impact in terms of improvement. To the ordinary athlete, lactate testing might seem daunting or even unnecessary at first glance. However, with this article, I wish to enlighten everyone about how they can benefit from such a test.
What is Lactate Testing?
This is an incremental step test consisting of 4-5 minute segments at predefined paces. Following each step, blood lactate levels are immediately analyzed and recorded. The main purpose of this test is to determine the athlete’s LACTATE THRESHOLD.
The lactate values for each step are graphed into what we call the LACTATE CURVE. Based on this curve, the athlete’s training zones are established. Contrary to what some people may think, peak lactate is not measured in this protocol. Rather, the lactate that can be sustained for given durations (ranging from a few minutes to several hours) is recorded. It is widely accepted that lactate values are one of the most important indicators of endurance fitness, more so than VO2Max or absolute strength.
What are the Top 5 Benefits of Lactate Testing?
Lactate testing allows you to…
General formulas and calculations for one’s training zones (whether HR or FTP) just aren’t that accurate. People have varying strength, speed, and endurance qualities that these formulas fail to consider.
For example, I have an athlete who’s 31 years old. Based on the general formula to calculate one’s Maximum HR, her max HR would be 189 bpm (220-Age); however, during testing, we found out that she could easily reach 203 bpm during hard efforts. Aside from this, if we use % calculations to establish her training zones and threshold HR, we will have huge errors in her profile. Calculations would imply that her Easy Zone is between (95-114bpm), yet in reality, her true easy zone based on blood lactate is (115-125bpm). Calculations estimate her threshold HR at around 150bpm; during testing, we found out her LTHR is 190bpm. Yes, she can maintain that HR for extended periods of time. That’s just how she’s made… a high-revving athlete. Formulas and calculations are based on averages, but they will probably not be a perfect fit for anyone.

Despite her high heart rate, this is normal for her. Her LTHR is 190bpm, which she can
sustain safely for roughly an hour.
When preparing for any race, time trials and intervals are an integral part of a properly structured training program. These short intense efforts give you a rough estimate of what you can sustain for the race. However, there are numerous situations where these sessions are an overestimation of what you can do for longer efforts.

His 20min time trial results in 241w which yields an FTP of 229w (241*0.95 = 229w)
When I tested my athlete’s Functional Threshold Power (FTP) via a 20 minute time trial, he was able to maintain 241w for the duration. The general rule of thumb is that 95% of this value would yield his FTP or 1 hour power. Based on this calculation, his FTP is 229w; yet, during testing we found out that his threshold power is roughly 217w. 12 watts might not seem like much for someone unfamiliar with power meters. But those with experience know that this is a large number that can either make or break your race. Once we adjusted his FTP and his other zones, he was finally able to nail his bike split for 40km and 90km bike splits.

His Lactate Curve indicates a threshold of 217w, 12w less than his estimated FTP (20 min time trial)

A linear “curve” depicting a weak aerobic base

A curve which would benefit from higher intensity work
Based on the shape of the curve, I can discern whether the athlete’s aerobic and anaerobic systems are balanced. A weak aerobic system would give a linear curve, this means that lactate accumulates in the blood stream during relatively easy efforts. A weak anaerobic system would result in a flat curve, this implies that the athlete lacks the strength and speed necessary to race hard and fast. A balanced curve means that lactate values are generally low when you need them (i.e. easy to moderate efforts), but are at just the right values when you go hard (i.e. Threshold, Vo2max, and Sprinting). By knowing the athlete’s curve, training recommendations can be made to improve on his weaknesses.
By comparing current and previous lactate curves, one can see the improvement (or lack thereof) in his/her performance. This will give the athlete an objective means of evaluation for his/her training regimen. Simply put, if the curve morphs into a normal curve or if it shifts to the right, we can conclude that the training block was a success.

The threshold improvement between Oct 2014 and Jan 2015
The graph above shows my athlete’s improvement over the course of a training program (using her lactate curve as a guide). Previously, she could only sustain 7.5 to 8 kph for her 10k, now, she can sustain 10 kph for the same distance. That’s 20-25% improvement within a few months of proper and intelligent training.
Some athletes like to train by feel. Lactate testing does not conflict with nor prohibit such a training approach. In fact, lactate testing allows one to align his perception of hard and easy with what is actually happening to him physiologically. Triathletes often fall into the “single speed” athlete category where we only know one speed in training and racing. This is mainly due to the fact that we often go too hard in our easy workouts, or too easy in our hard workouts. Having proper polarization between hard and easy sessions gives the best results. By going “truly” easy, we are able to go hard when we need to. Wiping oneself out during recovery sessions is a sure way to under perform or burn out (no more gas left in the tank). Conversely, by knowing exactly how hard your threshold is, you can use this to perform well during intense training sessions and race scenarios.

A sample table of different training/racing zones
To sum things up, lactate testing allows you to set your zones precisely (no more wasted time due to trial and error). This means that you get the most bang for your buck for every minute spent training. By knowing what areas you need to improve on, you get to dedicate the necessary time and effort to address these weaknesses. Continuous improvement comes from a smart training program.