By Coach Matt Russ for Performance Conditioning

There are a wide variety of clinical and non-clinical tests that can be used to evaluate a runner's fitness,

 establish training zones, and measure progress. Clinical testing can provide an impressive amount of information about an athlete's physiology, while running field tests offer a practical, inexpensive way to monitor fitness throughout the season.

Both have value, but they serve different purposes. The key is understanding what each test can tell you and, more importantly, how to apply the results to training.

What Does Clinical Testing Tell a Runner?

Clinical fitness testing provides a broad picture of an athlete's current physiological condition. A gas exchange or VO2 test can provide information about peak VO2, current fitness level, energy-system development and utilization, aerobic and anaerobic thresholds, and the athlete's ability to return to homeostasis following peak exercise. Depending on the testing protocol, it may also provide information related to genetic propensity.

Blood lactate testing provides another valuable measurement. By relating heart rate, running speed, power, exertion, and blood lactate concentration, a coach can develop a detailed profile of the athlete's fitness and establish individualized training zones.

Clinical testing protocols are also used in peer-reviewed research and clinical studies. Much of what coaches understand about exercise physiology, training methodology, and athletic performance is built upon this type of research.

For creating a "big picture" understanding of an athlete's fitness, clinical testing is difficult to beat.

The Limitations of Clinical Fitness Testing

Clinical testing does have drawbacks, however. The first is cost. Depending on the test, the athlete may face a significant expense, as well as the time required to schedule and complete the testing.

Another issue is the amount of data generated.

I have had athletes bring me stacks of charts, graphs, and numbers from clinical tests that they found difficult to relate to their actual training. Data without understanding or application has limited value. If the test results are not explained in terms the athlete can understand, the athlete may not receive much return on their investment.

The testing process itself can also be intimidating.

Blood lactate testing requires multiple blood samples, while VO2 testing requires the athlete to wear a mask that captures respiratory gases. Not every athlete responds well to these procedures, and few would describe them as particularly enjoyable.

For these reasons, I generally recommend clinical fitness testing once or twice per season, preferably after a peak. A completely unconditioned athlete or someone brand new to a sport may benefit from more frequent testing during their first season because fitness can change much more dramatically during this period.

Clinical testing can provide valuable benchmarks, but what happens between those tests?

This is where field testing becomes extremely useful.

What Is a Running Field Test?

Field tests do not provide the same volume of physiological information as clinical testing. Their advantages are that they are practical, inexpensive or free, easy to administer, and can be performed regularly throughout the season.

The primary purposes of a running field test are to:

1. Measure changes in fitness and performance.
2. Establish or update individualized training zones.

Some field-testing protocols are designed to predict clinical values. It is important to remember that these are predictions or estimates—not actual clinical measurements.

The major advantage of field testing is that it uses actual athletic performance to evaluate performance. When administered correctly and consistently, a field test can provide highly relevant information that can immediately be applied to an athlete's training.

Field Testing and Heart Rate Training Zones

Formula-based training zones, such as the commonly used 220-minus-age formula, can be highly inaccurate for individual athletes and should not be relied upon for precise athletic training.

Field testing generally uses a measured performance value to establish individualized heart rate training zones rather than relying solely on an age-based formula.

Training zones are also not permanent. They can change throughout a season and from year to year as an athlete becomes more fit, changes training, or ages.

Lactate Threshold Heart Rate (LTHR)

Many heart-rate-based field tests are ultimately trying to determine lactate threshold heart rate (LTHR). LTHR is used as a practical reference point for establishing individualized heart rate training zones.

Other systems use different methodologies. Jack Daniels' VDOT system, for example, uses running performance to establish training intensities, while other systems rely primarily on pace.

Ultimately, these different systems are attempting to divide an athlete's performance capacity into appropriate training intensities designed to target different energy systems and fitness adaptations.

There can be legitimate differences between testing protocols and training-zone systems, but I believe coaches sometimes place too much emphasis on which protocol is "right" or "wrong." In my experience, the administration, consistency, and accuracy of the test are often more important than arguing over the protocol itself.

Three Types of Running Field Tests

I divide running field-testing protocols into three basic categories:

• Ramp tests
• Time-trial tests
• Distance tests

Ramp Test

A ramp test requires a consistent increase in exercise stress, usually at one-minute intervals, until the athlete can no longer continue.

This type of test can be performed on a treadmill by progressively increasing speed, incline, or both.

Time-Trial Test

A time-trial test requires the athlete to run as far or as fast as possible for a prescribed period of time.

My preference is generally toward time-trial testing because it provides useful performance information while allowing the coach to record average heart rate, distance, pace, and perceived exertion.

Distance Test

A distance test measures how quickly an athlete can complete a prescribed distance. A track or accurately measured flat course is ideal because it makes the results easier to compare from one test to the next.

Basic Running Field Test for Lactate Threshold

A basic time-trial protocol for evaluating lactate threshold and running performance can look like this:

• Warm up with 10 minutes of easy running.
• Perform 4–5 x 100-meter run strides at a submaximal intensity.
• Run at an endurance intensity for 2 minutes, then increase intensity every 2 minutes until just under 5K pace.
• Hold slightly under 5K pace for 5 minutes.
• Recover with 8 minutes of easy running.
• Perform a 10-minute time trial, recording distance, pace, average and maximum heart rate, and perceived exertion.
• Cool down for 10 minutes.

The goal is to produce a strong, controlled threshold effort while collecting repeatable performance and heart-rate data.

Basic Ramp Test for Running Performance

A basic treadmill ramp test can be performed as follows:

• Begin running at 5 mph at a zero-percent grade.
• Increase the incline by 1% after each minute.
• Increase speed by 0.5 mph after each minute.
• Continue alternating speed and incline until the athlete "taps out" or cannot continue.
• Record speed, incline, and heart-rate data from the final completed stage.

Ramp tests are relatively easy to administer and can be useful for measuring performance.

Basic Distance Test for Running Performance and LTHR

A basic distance test can be performed on a track or flat course using GPS:

• Warm up for 10 minutes.
• Perform 4 x 100-meter run strides.
• Take a 400-meter warm-up lap while progressively increasing pace.
• Complete 2 miles as quickly as possible.
• Record total time, maximum and average heart rate, and perceived exertion.

Time-trial and distance tests can provide a useful picture of lactate-threshold performance when the athlete is properly rested and motivated.

How to Evaluate Field-Test Results

When reviewing heart-rate data, there should not be a large discrepancy between threshold and maximum heart rate. Heart rate should also show a relatively consistent pattern rather than becoming excessively erratic or stochastic.

Some variation is normal as the athlete approaches oxygen debt. Heart rate may also rise slightly during the final one or two minutes as the athlete becomes increasingly anaerobic.

Perceived exertion should be very high.

One of the most important measurements of improvement is efficiency. In simple terms, efficiency means producing greater output—such as faster running or greater distance—at the same or lower metabolic cost.

If an athlete can run faster at the same heart rate, or cover more distance without an increase in heart rate, that is a meaningful indication of improved performance.

The Athlete Can Be the Weak Link in Field Testing

The "weak link" in any field test can be the athlete themselves.

Not every athlete has the focus or ability to push themselves to a maximal or near-maximal level in a non-competitive environment. This can be especially true when the athlete administers the test themselves.

The purpose of a field test is to create conditions that resemble competition. The athlete should be properly rested, fueled, hydrated, and mentally focused.

Having a coach administer the test can improve the quality of the results. Testing multiple athletes together can also introduce a competitive element that encourages athletes to push harder.

Before the test, explain:

• Why the test is being performed
• How hard the athlete should run
• What the effort should feel like
• What data needs to be recorded

A small amount of competitive pressure can sometimes make a significant difference.

Establishing a Baseline

The first test establishes your baseline.

Once an athlete has a performance marker to beat, subsequent testing can become easier to administer because the athlete has an objective goal. Athletes will often push themselves harder when they know exactly what they are trying to surpass.

Most field time trials are less than 20 minutes. Even a short test can be extremely stressful, and some athletes have difficulty producing a true 20-minute effort outside of a competitive environment.

For this reason, I prefer a shorter test combined with a more extensive warm-up.

Consistency Is the Most Important Part of Field Testing

Of all the considerations involved in field testing, consistency is perhaps the most important.

If the testing conditions change significantly, the results may no longer be directly comparable. Athletes tend to place a lot of value on their test results, so testing should be as close to an "apples-to-apples" comparison as possible.

Ideally, keep the following consistent:

• Testing protocol
• Course or treadmill
• Environmental conditions
• Equipment
• Warm-up
• Athlete preparation

Heat, humidity, wind, elevation, course variations, and equipment differences can all affect the results.

If you change several variables between tests, it becomes difficult to determine whether an improvement or decline actually reflects a change in fitness.

Rest and Recovery Before a Field Test

The athlete must be sufficiently rested before testing.

I recommend performing a field test during the week following a rest and recovery week. This gives the athlete an opportunity to begin the test without carrying excessive fatigue from previous training.

Indoor treadmill testing makes it easier to control environmental factors such as temperature, humidity, and wind. However, treadmills can vary significantly in their calibration, which can affect speed and distance readings.

Try to use the same treadmill for repeated tests and, if possible, calibrate it before testing.

Treadmill running also produces more heat because there is less natural airflow around the athlete. A fan should be positioned directly on the athlete and used at a high setting. The resulting difference in cooling can affect heart-rate data.

Safety is another consideration, particularly when an athlete is not accustomed to running at high speeds on a treadmill.

Field Testing Should Be Part of a Bigger Picture

No test can completely describe an athlete's fitness.

Even a well-designed test only captures an athlete's performance during a relatively brief period on a particular day. The more data points a coach has, the more effectively they can "connect the dots."

Testing once per season provides limited information. A more complete picture can be created through quarterly field testing, periodic clinical testing, and consistent analysis of training and race data.

This allows the coach to look at trends rather than placing too much emphasis on any single test.

Every Race Is a Field Test

A race is, in many ways, a field test in itself.

Our athletes submit online race recaps containing detailed information about pace, power, heart rate, splits, environmental conditions, and other relevant metrics. This information is maintained in a database so we can compare performance from race to race and season to season.

Race data is also an excellent way to validate field-test results.

For example, if an athlete's heart-rate data during a race is significantly different from the heart-rate data recorded during their most recent field test, it may indicate that the athlete was not sufficiently rested or motivated during the field test.

Using 5K Races as Field Tests

"C" races and training races can be excellent field-testing opportunities.

I have found that several 5K races spread throughout the season can provide particularly useful data. A 5K creates the competitive environment that may pull an additional percentage of effort from the athlete that would be difficult to achieve during a solo test.

Remember, the goal of field testing is to capture a true threshold effort.

My protocol is to have the athlete perform a progressive warm-up before the race. I do not want them starting the race cold and immediately creating excessive oxygen debt.

I have the athlete record a split at the one-mile mark and another during the final 400 meters. At that point, the athlete is likely well above threshold and producing a very hard finishing effort.

The second split can then be used as part of the process for establishing heart-rate training zones based on lactate-threshold heart rate.

Using Technology to Track Running Fitness

Today's technology has made field testing much easier.

GPS-enabled heart-rate monitors allow athletes and coaches to separate individual metrics and collect pace, distance, and heart-rate data without requiring a coach to administer every test.

Training platforms also make it possible to graphically compare current and historical performance.

However, collecting data is only part of the process.

The coach must be able to explain what the data means and how it should affect training.

An athlete who understands their progress is more likely to become invested in the training process. Testing should not simply produce another collection of numbers. It should help the athlete and coach understand what is improving, what needs attention, and whether the current training plan is producing the desired result.

The Bottom Line: Test More Than Once a Season

Clinical testing and running field tests are not competitors. They are complementary tools.

Clinical testing can provide an extensive physiological profile and establish valuable benchmarks. Field testing provides a practical way to monitor performance and training zones throughout the season.

For most athletes, a combination of periodic clinical testing, quarterly field testing, race analysis, and consistent training-data review provides a much clearer picture of fitness than relying on any single test.

The goal is not to collect the most data.

The goal is to collect useful data, understand it, and use it to improve training and performance.

Matt Russ enjoyed a professional coaching career spanning over two decades of working with professional endurance athletes. His athletes have achieved numerous regional, national, international and championship titles under his direction. Matt achieved the highest level of licensing by both USA Triathlon and USA Cycling, and was a licensed USA Track and Field Coach. His accomplishments include being named "Team USA" Coach for the 2011 Beijing World Championship. Head Coach and founder of The Sport Factory, a USA Triathlon Certified Performance Center, he has authored many articles on a wide variety of endurance related topics.