Performance Diagnostics - Specialists and Information

Performance diagnostics focuses on the following organs:

• Heart
• Lungs
• Muscles

Various devices and examination methods are available for this purpose.

These include examinations of:

• Heart (electrocardiogram = ECG, ultrasound examination of the heart = echocardiography, heart rate monitor)
• Lungs (spiroergometry)
• Metabolism under exercise (lactate test)
• Body measurements (weight, height, body mass index = BMI, body fat percentage)
• Strength and reaction time (weightlifting or push-ups)

In principle, performance testing is also suitable for recreational athletes and non-athletes. Patients with heart disease, for example, undergo performance testing after heart bypass surgery or stent implantation. The goal for these patients is a gradually increasing program of physical exercise.

The most common area of application is sports, particularly competitive sports.

Typical examples of its use in recreational sports include:

• Preparation for a marathon
• Preparing for an extreme competition (such as a desert race or crossing the Alps)

In these cases, the primary goal is to determine whether there are any health concerns that would preclude such physical exertion.

The most important test results for the heart (both at rest and during exercise) are:

• Number of heartbeats (heart rate: between 50 and 200 beats per minute)
• Amount of blood ejected (stroke volume: 80–200 ml/beat; cardiac output: 4–36 L/minute)
• Heart muscle function (visible on the ECG and echocardiogram)

The most important test results for the lungs (both at rest and during exercise) are:

• Number of breaths (respiratory rate: 10–50 per minute)
• Volume of air inhaled and exhaled (tidal volume: 500–3,000 ml/minute)
• Oxygen demand at rest (150–300 ml), during exercise (up to 6 liters/minute)

The most important test results regarding muscle strength and metabolism are:

• Lactic acid (lactate 0.5–1.5 mmol/L at rest, rising to >10 mmol/L during maximum exertion)
• Maximum strength in weightlifting (1RM = one-repetition maximum is the maximum weight the athlete can lift once)

The procedure is standardized to allow for the comparison of individual measurement results across tests (which may be months or even years apart).

First, the physician measures and records body measurements such as height and weight. The physician also measures the heart rate at rest. This is typically done using a heart rate monitor. Normally, the patient continues to wear the heart rate monitor during the subsequent exercise test to record the heart rate response during exercise.

Doctors then conduct a sport-specific exercise test. This is usually done on a treadmill or stationary bike.

Performance test on a stationary bike @ rh2010 /AdobeStock

The increase in exercise intensity is also standardized, which is why this is often referred to as a step test. The defined intervals are 3 minutes. After that, the intensity is continuously increased.

Athletes usually reach their performance limit after 20 to 30 minutes. The heart rate rises as the workload increases. The maximum heart rate depends on the athlete’s fitness level and age.

Metabolic function and energy utilization are assessed using a lactate test. During the lactate test, the athlete takes a short break between intervals. The doctor draws blood from the earlobe during these breaks to determine the athlete’s lactate level.

Alternatively, spiroergometry is used to examine metabolic activity more precisely. Continuous measurement of respiratory gases (oxygen and carbon dioxide) is performed via a breathing mask. A break between individual exercise intervals is not necessary with spiroergometry.

Spiroergometry is a method for assessing the capacity of the lungs and cardiovascular system @ StefanBartenschlager /AdobeStock

For an athlete’s training success, it is important to know one’s own performance capacity and to tailor the training plan accordingly.

The lactate levels and their increase over time can be used to determine the so-called anaerobic threshold. This is the point at which metabolism transitions from using oxygen (aerobic) to not using oxygen (anaerobic). This range represents the limit of endurance capacity. Below this threshold, athletes can typically sustain long-duration endurance performance (such as a marathon).

For endurance athletes, the majority of training volume should be below the anaerobic threshold. However, shorter and more intense training sessions at or near the anaerobic threshold are also important for improving performance.

Through such high-intensity training sessions, the athlete can apply targeted training stimuli and raise their anaerobic threshold. This makes it possible to maintain higher speeds for longer periods.

In the past, lactate was considered the villain in endurance sports, as it was assumed that lactate led to a decline in performance.

However, there are now also positive aspects, as athletes have learned how to use lactate to their advantage. A continuous improvement in performance through specific training methods leads to an increase in lactate concentration.

A higher concentration, in turn, leads to greater lactate tolerance. This means that the better an athlete can cope with the increased lactate concentration, the less their performance is affected.

The normal lactate level at rest is 0.5–1 mmol/L.

As exercise intensity increases, it initially rises gradually and then rises sharply once it reaches a value of 4 mmol/l. The point at which the value rises sharply varies from person to person.

The lactate curve illustrates the threshold between aerobic (with oxygen) and anaerobic (without oxygen) metabolism—the so-called anaerobic threshold. 

As training progresses, this threshold shifts to the right (i.e., toward a higher level of exertion). This rightward shift is visible between performance tests and serves as evidence of a positive training effect.

Lactate is measured using a blood sample from the earlobe @ M. Siegmund /AdobeStock

VO2max is an abbreviation for the maximum amount of oxygen an athlete can consume. 

The unit is ml/kilogram of body weight/minute (ml/kgBW/min). 

A good value for women is > 45, and for men > 51. Professional endurance athletes can reach up to 80. This means that the athlete can take in over 6 liters of oxygen per minute.

Even non-athletes can undergo a performance test, which is useful for training planning. 

One goal may be to improve fitness without jeopardizing health or overtaxing the body. The latter is associated with a significantly increased risk of injury.

Performance testing is classified as an individual health service (IGel), which health insurance typically covers only in exceptional cases. You should clarify coverage with your insurance provider in advance. The cost ranges from approximately 150 to 250 €.