Lactate Threshold Testing Protocol
By Rich Strauss

Before you go any further, please read Training Zones Explained and New to Training with a Heart Rate Monitor. This article will build on these concepts and deal specifically with how to determine your training zones.

Before I start, I want to answer The Big Question: Do I really need to do all of this stuff?

Answer: It depends.

In my experience, if you are new to the sport and new to training with a heart rate monitor, then following this protocol will give you more accurate training zones and eliminate a lot of confusion for you. The biggest danger for a new triathlete is doing too much, too fast, too soon. Training with a heart rate monitor will provide a rev limiter for your engine, until you learn more about endurance training and about your body. This adaptive process is accelerated when you know what you are doing and you have determined accurate training zones. For these reasons, I think it is a good idea to perform these tests very early in your training.

For more experienced and disciplined athletes, it's probably not necessary to test right away. I would recommend, however, that you test at the end of Base 1 and again at the end of Base 3. These periods mark the transition to more intense training phases, when it is a good idea to have an accurately defined lactate threshold heart rate.

Most desirable training adaptations occur in relation to how closely you train to your Lactate Threshold Heart Rate (LTHR). Some benefits are gained by staying away from this red-line, others are gained by bouncing around the line. I wanted to create a testing system that gives an accurate estimation of LTHR, and also uses the resources that are available to most athletes.

Swim, Bike, Run

First of all, understand that your training zones for each sport will be different. Your heart rate measures the cumulative stress on your body: your physical exertion as well as hydration state, body temperature, the effects of gravity, etc. Swimming is the least stressful, so your training zones will be lowest on the swim, then higher on the bike, and highest for the run. So, a few points:

1. Because it is difficult to get your pulse in the pool, it is better to use pace to determine intensity. Perform a time trial (about 1000yd/m) and determine your per 100yd/m pace. This is called your T-pace. Then define how hard to work in a set by referring to this t-pace: 10 x 100 @ t+5, means you want to do these 100's at your t-pace, plus 5 seconds. You can also get a quick heart rate by counting your pulse for 10 seconds and multiplying by 6.
   
   
2. It's possible to have a bike LTHR this is 10+ beats lower than your run LTHR. Therefore it is a good idea to perform the tests below for the both the bike and run, then determine training zones for each sport.

Two or More Independent Means
of Computing Firing Data

Sorry, this is an artillery thing. What I try to do is use more than one method. Each method either confirms or denies the results of the other methods. The methods I use are Calculator Based, Performance Based, and Perceived Exertion:

1. Calculator Based: my term. These are methods that require you to input some numbers such as age and heart rate into a formula and out pops your training zones. The two most common are Age-Based and Karvonen. For an easy to use spreadsheet, click here. (Microsoft Excel needed)
   
   
   • Age-Based: this is probably the one that came with the instructions for your heart rate monitor. You know, 220-age, multiply by x%. In my opinion, absolute junk for an athlete. Sorry, but I have seen more confusion caused by the results of this formula than by any thing else in this sport. Why? Everyone is different. 220 - age? This says my max is 186. I've seen 197 many times.
     
     
   • Karvonen: this method uses max heart rate, but also accounts for different levels of fitness. This increased fitness is most commonly demonstrated by a decrease in resting heart rate. Basically, the Karvonen Method uses your max heart rate to determine your training zones, but then adjusts for your level of fitness by taking into account your resting heart rate. This is the one I use.
     
     
2. Performance Based: my term again. These are methods that require you to perform some kind of a test, such as a time trial. You then use the results of this test to estimate your LTHR. The two most common are Conconi and Time Trial.
   
   
   • Conconi: this is an involved method that is most accurately performed on a Computrainer for the bike, or on a treadmill for the run. Because not everyone has access to these items, and because they are rather complicated, I will touch briefly. The Basics: the athlete starts out at a light work load. This workload is defined in watts on the Computrainer and mph on the treadmill. Starting heart rate is recorded. At 1 minute intervals, an assistant increases the workload by an increment (20 watts, for example). At the same time, the assistant records the athlete's heart rate, power (or mph), and Perceived Exertion on a scale of 6-20 (see scale below). This process is repeated in one minute increments. At some point in the test, hopefully, four things will happen. First, heart rate will rise suddenly (the graph of heart rate over time suddenly curves up). Second, the rate at which power (or pace) is increasing suddenly decreases (it gets much harder to continue to increase effort). Third, the athlete looks at the PE scale and says "16 or 17, yep, this is pretty freakin' hard." Fourth, the assistant notes that the athlete's breathing becomes labored. The heart rate at which (hopefully) all four things occur is defined as your LTHR. Ouch, my head hurts.
     
     
   • Time Trial: most commonly used, but also misinterpreted. This method is described by Joe Friel: perform a 30 minute time trial, as if in a race. Pace your effort so that you don't die too soon, or finish with too much gas. At 10 minutes, hit the split button on your heart rate monitor to record your average heart rate over the last 20 minutes of the test. This average heart rate is an estimation of your LTHR. However, there is a problem here. If you use the Conconi method above, and then use the Time Trial method, you can often experience a difference of 4-12 beats per minute between the two tests. Depending on the athlete's conditioning, mental state, motivation, pain tolerance, etc., it is possible to maintain a heart rate well above your LTHR for a considerable amount of time. For example, I've tested myself on my Computrainer several times and am confident that my LTHR is about 172-174 bpm. However, I can do a climbing trial and average 183 for 40 minutes. I can do a sprint tri and average 180+ for 55 minutes.
     
     
3. Perceived Exertion: this is quite simple and best performed on a trainer or on a treadmill. Increase your effort incrementally, paying attention to how you feel. When you recognize the symptoms of approaching and passing your LTHR, you're there. These symptoms are:
   
   
   • Breathing suddenly becomes "labored."
     
     
   • You feel a burning sensation in your legs, as lactate begins to accumulate. This is easier to sense on the bike than on the run.
     
     
   • It suddenly becomes difficult to continue to increase your effort. Notice I said "increase," not "maintain." It gets harder to go faster, but you might feel as if you are able to maintain this effort for quite a while.

Step 5: Perceived Exertion

This is best done with your bike on a trainer. Make a copy of the Rating of Perceived Exertion (RPE) Scale below and put it somewhere you can see it, along with your LTHR from Method #1. Start at an easy pace and normal cadence. At each minute, increase your speed by 1 mph. At the same time, take a look at the scale and make a mental note of your PE, or have someone record it for you. As you get closer to your Method #1, start paying very close attention to how you feel. Ideally, as you approach this number, you should feel the "symptoms" described under Perceived Exertion above. Regardless, record the heart rate at which you did feel these symptoms. This is Method #2. Don't worry, if you do this test correctly, it will probably only last about 10-12 minutes. When you feel the symptoms enough to know they are there, you have accomplished the purpose of the test. Stop.
About 172-174, using a Computrainer.
Method #2=173

Step 6: Time Trial

Perform a 30 minute time trial, as if in a race. Pace your effort, so that you don't blow up too soon, or finish with too much gas. At 10 minutes, hit the split button on your heart rate monitor to record your average heart rate over the final 20 minutes. Record this average heart rate.
Probably about 185-187.

Step 7: Apply the Experience Discount

Now this is where we use a little Black Magic. Remember how I said that depending on the athlete, it's possible to hold a heart rate well above your LTHR for several minutes? Using this scale, subtract the appropriate number from your Step 6 heart rate and determine an estimate of your LTHR. The result is Method #3.

I have a lifetime of anaerobic sports (swimming), 2 years of IM training, and with the right motivation, I can "suffer." However, I am not a Freak. I'm going to use a discount of 11 points. 186-11=175. Method #3=175

Step 8: Compare Results, Apply SWAG (Scientific Wild Ass Guess) + Commonsense

• Method #1 = 174
  
• Method #2 = 173
  
• Method #3 = 175

174 looks good to me. I'll use this one.

Step 9: Apply LTHR and determine your training zones

Use the spreadsheet you downloaded above to determine your training zones. You will want to use the LTHR method. Then refer to Joe Friel's Triathlete's Training Bible and Training Zones Explained, for more information on how to use these training zones.

Step 10: Periodically Reassess your LTHR

If you are a beginner, your LTHR will go up as your fitness increases. It's a good idea to periodically repeat this testing, to make sure that you are still exercising at the appropriate intensity. This is particularly important when you are about to enter a more intense training phase. Also, pay attention to your body during training and look for the symptoms of approaching your LTHR. This will help you further refine this number.

In the end, your LTHR and the resultant training zones are only tools. Just as with any tool, you need to know how to use it properly. Refer to my other heart rate training articles for further guidance.

Max Heart Rate Tests

Note: these are extremely stressful tests. If you have any doubts about your ability to perform these tests safely, DON'T, or consult with a physician first.

Run

1. Find a steep hill that will take you about 1 minute to run at max effort.
2. Warm-up with 10-15 minutes of easy running, stretch, run another 5 minutes.
3. Start your heart rate monitor.
4. Run up the hill, at about a 6 on a scale of 1-10.
5. Quickly run down and immediately repeat, about level 8.
6. Run down and repeat, absolutely max effort. Don't pace your effort, just sprint. Keep going until you can go no further. Stop at look at your HRM, this is your max heart rate.

Bike

1. Find a steep, safe hill, preferably with a leading flat quarter mile.
2. Warm up thoroughly, allowing your heart rate to rise to about 15 on the RPE scale below.
3. From a rolling start, start your heart rate monitor and sprint towards the hill.
4. Sprint up the hill, out of the saddle.
5. At the top, look at your heart rate monitor, this is your max heart rate.

Sample Testing Week (test during a recovery week)

Rating of Perceived Exertion Scale (RPE)