Run Assessment and Testing Protocol

There are a two things regarding Ironman running that we could accomplish through regular and simple testing protocols which include the following;

1. An approximate lactate threshold heart rate on the run.
2. A method of benchmarking our aerobic running abilities which closely simulate Ironman racing requirements.

Let’s go through each of these with actual numbers to assist you in assessing and improving your Ironman running.

Establishing Approximate Lactate Threshold

One of the first things an aspiring Ironman should do is establish an approximate level for running lactate threshold. The purpose of this article is not to define or debate the essence of establishing a scientific reading of your lactate inflection point but rather to provide a simple method of using practical information and data for your training and racing.

To keep things simple, the lactate threshold (LT) is the point during exercise intensity whereby lactate in the blood starts to accumulate at a rate faster than it can be removed or metabolized. Training or racing below the lactate threshold allows the body to remove the lactate produced by the muscles without accumulating.

Why is establishing a lactate threshold important? Establishing your lactate threshold is very helpful for deciding training intensities to accomplish certain physiological benefits during a training program. Most importantly, they allow an athlete to establish heart rate zones to establish intensity levels during run training.

A very simple method of determining your approximate lactate threshold for run purposes is to run a 5k race and capture the average heart rate data for each mile and for the entire race. We could use these numbers to build out our training zones to guide us in our run intensity that stresses appropriate physiological adaptations during our training.

The key is to run a 5k reasonably paced to get accurate data. What we don’t want to do is come out of the gates guns-a-blazing hitting our maximum heart rate within the first mile and then fade away while letting the pace and intensity wither away over the next 2.1 miles.

Below is an example of data from a 5k race used to establish LT and training zones for the run;

What we obtained from this test is that the average pace per mile is 6:51 and the average HR used to determine LT is 168 bpm. The next step is to calculate some heart rate training zones. If we use some classic Friel (see any of Joe Friels outstanding training reference books) we could apply the following percentages to the LT of 168 bpm to calculate the training zones;

From a practical standpoint, many Ironman athletes have been successful in using slightly different definitions or training zones for the vast majority of their Ironman specific run training that is similar to the following assuming an LT for this athlete of 168 bpm;

During the season, there are many athletes that would consider the ENDURANCE ZONE their running “sweet spot” for training. Interestingly, this sweet spot correlates in a very similar fashion to using another range based on Phil Maffetone’s guidelines.

To calculate an Ironman endurance zone using the Maffetone formula, the athlete would subtract their age from 180 to establish the bottom of the zone and then add 10 beats to establish the upper end of the zone. In this case, the athlete was 37 years old at the time of testing. 180 minus 37 equals 143 and then adding 10 beats is 153. In this case the two different methods gave us the exact same numbers (an endurance zone range of 143 to 153 heart rate). Through using these numbers repeatedly in training, the athlete will learn their own bodies to fine tune where their own physiological breakpoints are when training at certain intensities. Note that these two methods of establishing zones may not always give the exact same results. That’s where the athlete (and coach) could verify through training and monitoring.

The purpose of these testing protocols is to provide us with a quick and easy way of establishing proper training intensities that prepare us for the demands needed to succeed during an Ironman race. We aren’t attempting to set personal records in the 5k or open marathon races. We are attempting to run a marathon to our potential after swimming 2.4 miles and cycling 112 miles.

Benchmarking Aerobic Running Ability

Running an Ironman marathon after swimming 2.4 miles and cycling 112 miles requires a tremendously efficient aerobic system. The physiological tools needed to run the Ironman marathon to your potential are much different than the tools that would be needed to run a fast single mile, a 5k or an open marathon. For this reason, we see many athletes that have a blazing fast single mile, 5k or open marathon times but don’t come anywhere close to replicating those efforts during an Ironman. Executing a fast Ironman relies on an athlete’s aerobic system rather than anaerobic system and their ability to metabolize fat as a fuel source rather than carbohydrates or muscle glycogen.

So how do as athlete assess their aerobic running ability rather than their anaerobic running ability? Simple, perform periodic aerobic running tests. One benefit of performing aerobic running tests is that they are good workouts that don’t over tax our muscular or aerobic systems, don’t require a substantial amount of mental energy and don’t require any significant recovery time.

Athletes can use either 88% of their LT heart rate or the top number from using the Maffetone calculation. Using the athlete data above, the athlete’s age is 37 and 88% of LT is 148. Again, in this case each of the tests give us the same testing HR of 148. From there, the athlete would perform about a 10 minute warm up at a local ¼ mile track and then run 3 miles (12 laps) while running at a consistent heart rate and recording each lap split. Since this test makes a good short endurance workout, the test could be performed quite often but should always completed on the same track. Other things that could impact data is the time of day, how rested and recovery the athlete is on testing day and the weather. Obviously on hot and humid days, we would expect to see slower lap times.

After completion of the tests, the tests could just be compared one against the next to monitor to see if the athlete is making progress, staying the same or moving backwards. Again, the athlete should understand that fitness changes based on the time of year and where they are in their key race build up. Ideally, the athlete should be witnesses increasing aerobic performance as their Ironman race approaches.

Below are examples to demonstrate how aerobic tests could be used to monitor progress.

Some athletes might look and say, “What’s the big deal about going from 2:04 per ¼ mile to 1:57 per ¼ mile?” The difference of 7 seconds per quarter mile is 28 seconds per mile. Extrapolate that over the course of an entire 26.2 marathon and that translates to a difference of 12 minutes and 15 seconds. That’s pretty good improvement and forward progress over the course of a few months of training.

Just to reiterate, aerobic progress does not always occur in a linear fashion. For example, if an athlete were to perform this exact same test on the first day of every month for 12 months straight, they wouldn’t see the same improvement month over month. If it is off-season and they are not in peak shape, they often will see a temporary regression of fitness. This is a natural part of periodization. But over time, trend lines develop and the data will demonstrate if we are getting a good return on out training time investment that is directly correlating to the physiological requirements of aerobic Ironman running.

The most useful trends lines are those when we compare year over year data or month over month when completing the aerobic tests during a 12 or 16 week Ironman specific build.