Method for Fitness Assessment
The Fitness Score application provides a powerful fitness evaluation tool that can assist personal trainers in developing customized exercise programs, track client progress, and improve his or her overall fitness levels. The Fitness Score assessment is based on spectral analysis of the intervals between the R-waves of heartbeats (R-R). Heart rate variability is subsequently used to recognize the Functional Capacity and Adaptability levels via newly patented methods and algorithms (US patent # 8,682,421 B2) based on the Theory of the Frames by Dr. Marvin Minsky [MIT 1974], which has been well-established in the field of artificial intelligence.
Historically, other companies and manufacturers have not analyzed heart rate variability for the assessment of autonomic nervous system function or fitness evaluation. Instead, they have attempted to use R-R intervals derived from electrocardiograms or time intervals between heartbeats derived from photoplethysmography (PPG). While PPG can be used to monitor the heart rate, it is not suitable for spectral analysis as it does not allow for accurate detection of high-frequency modulation within the sinoatrial (SA) node. This modality, therefore, lacks necessary precision, which has disqualified it from being approved by Medicare for assessment of autonomic function. In contrast to these other techniques, the Fitness Score application utilizes H6, H7, H9, or H10 Polar devices. These devices allow for the detection of R-R intervals derived from an electrocardiogram at a very high sampling rate (e.g., 2000 Hz), which significantly increases their accuracy and allows for spectral analysis. This methodology has since been scientifically proven to monitor the body’s functional integrity and therefore provide an accurate evaluation of fitness levels.
The Express Fitness Test
The Fitness Test can be quickly performed in only three to four minutes using a combination of simple body position changes and deep breathing. The simplicity of the maneuver, which requires just lying, standing, and sitting, allows clients to perform the test at any location at any time. Following the short test, the results are immediately displayed on the screen.
During the test, the heart rate variability data is recorded and displayed in a special graph, known as a Rhythmographic strip or Rhythmogram, as shown below.
Each vertical blue line in the rhythmogram corresponds to the interval between two consecutive heartbeats, with the length of the line corresponding to the length of the interval in seconds. As the test is performed, blue lines are added to the horizontal axis to form the rhythmographic strip. This graph shows one’s heart rate fluctuations throughout an entire test, known as the Heart Rate Variability portrait.
The fitness test, or Orthotest, involves four stages:
- Supine Stage: Client lies on his or her back.
- Transition period: Client changes position from lying to standing.
- Upright stage: Client stands quietly for 1 to 2 minutes.
- Deep Breathing Stage: Client breathes deeply while standing or sitting.
The rhythmogram above demonstrates the four stages of the fitness test.
Quantitative Fitness Evaluation Based on R-R Interval Variability Analysis
The assessment of functional capacity is based on the relationship between spectral functions as calculated by spectral analysis. On the left side of the image below, you can see a nearly optimal relationship between low and high-frequency components of the spectral function. The algorithm calculates the discrepancy between optimal variability and actual cases using the method described in the US Patent mentioned above. Physiologically, this approach to functional capacity is based on the principle of balancing sympathetic and parasympathetic nervous system activity during the Orthotest. In other words, functional capacity is better in individuals able to properly balance the activity of the autonomic nervous system throughout the simple positional change from supine to standing.
The Fitness Score is displayed in the application as a Fitness Chart. The Fitness chart graphically represents the results of the quantitative heart rate variability analysis conducted during the orthostatic fitness test. Therefore, the chart provides an “instant snapshot” of the client’s fitness score in the form of a functional capacity and adaptability rating.
Functional capacity is a component of fitness that represents the ability of an individual to efficiently perform a task in a multitude of circumstances. Functional capacity serves as an indicator for overall well-being and can vary in response to acute stressors or major lifestyle changes.
Heart rate variability serves as an excellent indicator for the functional capacity of an individual. High variance in the intervals between heartbeats results in the formation of a wavelike pattern on the rhythmographic strip, with higher functional capacity levels resulting in more distinct waves. Optimal functional capacity has even been referred to as the “dance of the healthy heart.”
Rhythmogram in a Well-Trained Athlete
Rhythmogram in an Untrained Individual
The rhythmograms of a well-trained athlete and an individual without training are shown below. Heart rate variability is more pronounced in the rhythmogram of the well-trained athlete, while the rhythmographic strip of the untrained individual is almost flat. Flat rhythmographic strips occur when the intervals between heartbeats are the same length. The lack of variance in the flat rhythmographic strip correlates with a lack of cardiovascular activation in response to external triggers.
Adaptability measures the responsiveness of the cardiovascular system to physical activity and other external triggers. In other words, adaptability represents the ability of the heart muscle to adapt to varying amounts of demand. Levels of adaptability are higher in individuals with a more responsive cardiovascular system. This component of fitness can be significantly improved with a proper diet and exercise program.
Functional capacity and adaptability are complementary but distinct components of fitness that require unique methods for evaluation. Functional capacity levels are ideally determined by heart rate variability spectral analysis determined during the stationary phases of the test (e.g., the Supine and Upright stages). In contrast, adaptability is best measured during spectral analysis of the transition period. Comparison of the transition portion of the rhythmographic strip of the well-trained athlete and unfit individual highlight the significant differences in adaptability. In essence, individuals with higher adaptability, such as the well-trained athlete, will exhibit curves that are steeper and more pronounced during the transition period.
It is important to note that the functional capacity and adaptability levels do not directly depend on each other. A person with a low ability to adapt to physical loads may still be able to efficiently manage stress in general. This combination would correspond to a low level of adaptability and a high level of functional capacity. With that said, these two fitness components most often demonstrate a high degree of correlation, as individuals with higher overall fitness levels typically exhibit elevated adaptability and functional capacity. Moreover, clients with suboptimal fitness levels can demonstrate significant improvements in both adaptability and functional capacity with adherence to a well-designed exercise program and healthy lifestyle changes guided by a personal trainer.
The Fitness Score application displays the Fitness Chart with functional capacity on the X-axis and adaptability on the Y-axis. Functional capacity is scored on a scale from 1 (highest) to 13 (lowest). Adaptability is scored on a scale from 1 (highest) to 7 (lowest). The chart further contains three distinct color-coded zones: 1) Dark blue zone (top left corner) corresponds to athletic fitness levels, 2) Light blue zone (middle) reflects average values of fitness in the general population, and 3) Red zone (bottom right) represents very poor and suboptimal levels of fitness. The client’s fitness score for each test will be marked by a yellow dot.
INTERPRETING TEST RESULTS
The test results are displayed on the screen so that you and your client can view his or her fitness score. However, interpretation of the results must be performed exclusively by the fitness professional. The results should be interpreted with consideration for the client’s base fitness level, age, and existing health conditions. This is essential, as an identical fitness score may indicate an improvement in one client but be a sign of overtraining in a different client. For this reason, it should be emphasized that clients should not alter their training programs independently based on their scores alone. Instead, they should be encouraged to always consult with their personal trainer or an exercise physiologist who can adequately evaluate their training program and find an optimal solution on an individualized basis.
Fitness scores within the lowest levels of functional capacity and adaptability (indicated by the red zone on the fitness chart) require urgent attention. Individuals in this zone should discontinue further exercise and consult a fitness or health care professional before engaging in additional physical activity.
Detection of Over- and Under-training
The client’s performance and fitness level can be adversely affected by both over and undertraining. In both cases, individuals will demonstrate a shift in their fitness score down and to the right on the fitness chart.
Hallmarks of Overtraining
In the early stages, overtraining is typically characterized by a reduced functional capacity but unchanged adaptability. However, clients who continue to overtrain will enter the exhaustion stage, characterized by a significant reduction in both functional capacity and adaptability.
Detecting Effects of External Factors
A reduced fitness score may also reflect a client’s response to other factors outside of their training program, such as increased stress at work or even increased consumption of caffeine or alcohol. The charts below show the fitness level of an individual before and after alcohol consumption.