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7.2 Collecting Resting Fitness Data

CHAPTER 7: Health and fitness assessment: Collecting and Analyzing Information 7.2 Collecting Resting Fitness Data
Resting fitness data might seem insignificant at first glance. Still, it plays a crucial role in monitoring progress and is a reference point when starting your clients’ fitness journey. For example, an elevated Resting Heart Rate (RHR) is associated with a higher mortality risk (Magnus et al., 2013). Monitoring Blood Pressure is just as important, if not more so, due to its correlation with Cardiovascular disease (CVD). Aerobic exercise can decrease resting blood pressure (Kelley GA et al., Prev Cardiol. 2001), making it worth monitoring and keeping an eye on the progress. Since resting fitness data encompasses more than simply RHR and Resting Blood Pressure, there are multiple reasons why collecting this data is vital for establishing reference points and tracking your clients’ progress. Let’s look at what we categorize as resting fitness data:
  • Height
  • Bodyweight
  • Resting Heart rate
  • Resting Blood Pressure
  • Circumference measures
  • Caliper testing measures
  • Body Composition Analysis
  • *Bloodwork (Lab tests)
  • **DNA Testing
For assessing your client’s Body Composition, you can use various methods, and circumference measurement and skinfold caliper are two methods you can use. There are, of course, more methods for body composition analysis, such as bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DEXA), and hydrostatic weighing. However, we believe that not all of them will be practical or accessible for you as a personal trainer. The most useful and easy to access is to use circumference measures or BIA since it will be less invasive than others. Skinfold measurements might be anticipated with specific clients. However, we want to emphasize one very important perspective on skinfold measurement. Despite its limitations, we appreciate the skinfold caliper testing method. However, we have not included it in our certification courses. It is essential to recognize that it is one of the most invasive tools to use and can potentially make your clients feel uncomfortable. In addition, asking clients to remove their clothes and pinch their skin may not be an experience they eagerly anticipate. Another concern with caliper testing is the accuracy and relevance of measurements, which are highly dependent on the practitioner’s skill set. Following a strict protocol when performing the measurements is crucial, which can be time-consuming and inconvenient. Considering the nature of caliper testing, it is advisable to use this method primarily with already fairly lean clients, ensuring maximum accuracy. Consequently, employing this technique with athletes and well-trained individuals with relatively low body fat percentages may be more suitable. Utilizing this method for clients with body fat percentages above 18% for males and above 25% for females will most likely lead to inaccurate results. As caliper testing may yield less accurate results, particularly if you lack experience in its application, we recommend considering an accredited ISAK course in anthropometry if you wish to incorporate this method into your practice. As you may have noticed, we marked lab tests (bloodwork) and DNA testing as these areas require specialized expertise to interpret. We emphasize that bloodwork results are highly complex and should be interpreted by medical professionals. However, you may still find value in understanding cholesterol results from the lab test, as they can provide insight into your client’s overall health. DNA testing is a slightly different matter. You will notice that the PT Business Academy offers a specialized certification course designed to help trainers leverage DNA tests effectively. We recognize the importance of this information and have created the DNA Fitness, Nutrition & Health Coach program in partnership with experts in the field. This program educates personal trainers on using DNA testing in fitness and nutrition, enabling them to provide more tailored and effective programs for their clients. Expanding your knowledge and skills in these areas can offer your clients a more comprehensive and personalized service, setting you apart as a highly skilled and valuable fitness professional. By mastering these techniques and carefully selecting the appropriate assessment methods for each client, you can provide your clients with valuable insights into their body composition and track changes over time, allowing them to understand their progress better and, with your guidance make informed decisions about their training and nutrition.

Resting Heart Rate

To measure RHR, use a watch or a heart rate monitor. The ideal time to measure RHR is after waking up and before getting out of bed, as the body is relaxed and free from the influences of recent physical activity or stress. Have the client lie down comfortably and breathe normally for a few minutes to ensure a relaxed state. Next, locate the radial pulse (on the wrist) or the carotid pulse (on the neck), and count the number of beats for a full 60 seconds using a watch or a heart rate monitor. Keep track of the beats and record the result as the client’s RHR.
Measuring RHR consistently, under the same conditions, and at the same time of day will provide more accurate and reliable data. In addition, tracking RHR over time can help personal trainers monitor their clients’ cardiovascular fitness progress. In recent years, smartwatches and fitness trackers have become increasingly popular for their ability to measure heart rate and other health parameters constantly. Many of these devices have heart rate sensors that automatically record resting heart rates throughout the day, providing valuable data without manual measurements.
Clients and personal trainers can easily access and analyze resting heart rate data over time by using the right apps and syncing the smartwatch with a smartphone. This information can be beneficial for tracking progress, adjusting training programs, and evaluating overall cardiovascular health. Some smartwatches also offer sleep-tracking features, which can provide insights into sleep quality and duration. Monitoring sleep patterns is essential, as poor sleep can negatively impact recovery, mood, and overall health. By using smartwatches to track both resting heart rate and sleep quality, personal trainers can obtain a more comprehensive understanding of their client’s health and make more informed decisions regarding their fitness programs.

Height and weight

Height and weight measurements are fundamental components of fitness assessments, providing baseline data to monitor progress and inform training programs. It is crucial to follow standardized procedures and best practices to ensure accuracy and consistency in these measurements.

For measuring height:
  1. Use a stadiometer or wall-mounted measuring tape.
  2. Ask the client to remove their shoes and stand with their back against the wall, heels together, and head in the Frankfort horizontal plane (eyes looking straight ahead). The client’s posture should be upright, with their weight evenly distributed across both feet.
  3. Lower the stadiometer headpiece until it rests gently on the client’s head, and then record the measurement.
Weight can be measured using a calibrated digital or balance-beam scale. Clients should wear minimal clothing to ensure accurate results. Place the scale on a flat, hard surface to prevent any discrepancies in the reading. Consistency in measurement conditions is essential for tracking progress accurately. Measurements should be taken under the same conditions each time, such as the same day of the week and at the same time, to obtain reliable data. Consistent clothing and fasting conditions should also be maintained.
When evaluated individually, body height and weight offer a partial understanding of a person’s health and activity status. Similarly, assessing weight without considering body composition does not accurately reflect an individual’s health risks or obesity levels. Body composition refers to the proportion of fat, muscle, bone, and water in a person’s body. For example, two individuals with identical height and weight may have significantly different body compositions, with one having a higher percentage of body fat and the other possessing more muscle mass. Consequently, their health risks and overall fitness levels can vary substantially. Therefore, a more comprehensive assessment of a person’s health should include body composition analysis, which is discussed later in this section. Health professionals can use body composition analysis alongside height and weight measurements to create more effective and tailored exercise and nutrition programs. By improving body composition rather than just weight loss, individuals can achieve better overall health, decreased risk of chronic diseases, and enhanced physical performance. Body height and weight measurements are essential for determining body mass index (BMI), which is explained below.

Body Mass Index (BMI)

Measuring height and weight is crucial for interpreting body composition changes due to fitness training. One of the simplest body composition analyses is Body Mass Index (BMI), which is calculated by taking a person’s weight and dividing it by their height squared. The standard practice is to use metric units. For example, if your height is 1.82 meters, the divisor of the calculation will be (1.82 * 1.82) = 3.3124. If your weight is 70.5 kilograms, your BMI is 21.3 (70.5 / 3.3124).

A high BMI is related to the risk of type 2 diabetes and hypertension.

Sanada 2012

A note on BMI

BMI is frequently discussed in the medical field, and general physicians may sometimes use it for classification purposes. However, it is essential to understand that BMI is not particularly useful for individual classification. Since the equation does not consider individual factors such as Lean Body Mass (LBM), it cannot be used to determine potential health risks accurately. For instance, an individual with a higher body weight due to a high LBM might be classified as obese even though their body fat percentage could be well under 12%.

Circumference measurement

These measurements help personal trainers evaluate a client’s body composition and track their progress over time. Moreover, they can be instrumental in identifying potential health risks related to excess body fat.

How to Perform Body Circumference Measurements: To ensure accurate and consistent measurements, follow these guidelines:

  1. Use a flexible, non-stretchable measuring tape.
  2. Take measurements on the client’s bare skin without clothing interfering.
  3. Apply consistent tension on the measuring tape – not too tight or loose.
  4. Measure at the end of a normal breath with the client in a relaxed position.
  5. Repeat each measurement twice to ensure accuracy and average the values if needed.

Here are some common circumference measurement sites and their respective standardized values for males and females:

Circumference measurements can be useful predictors of health problems, such as waist circumference correlating with heart disease risk. In addition, seeing changes in body dimensions can motivate clients with different goals, whether it’s losing fat or gaining muscle. However, some clients may feel self-conscious or demotivated if their progress could be more significant.

Personal trainers should use specific anatomical landmarks and follow established guidelines to ensure accurate measurements. Measurements should be made with a non-elastic, flexible tape that fits snugly against the skin without pressing into the subcutaneous layers. In addition, clients should wear thin, form-fitting clothing that allows for precise measurements. If they agree and feel comfortable, measurements should be taken without clothes covering the body landmarks.

Personal trainers should initially measure each site only once and then take duplicate measurements. If the recorded values differ by more than 5 mm, remeasure after waiting 20-30 seconds. Many of these assessments can be used alongside body-composition assessments, following the same protocols. Trainers should explain each procedure, ensure the client’s comfort, and use precise landmarks. After recording the values, trainers should discuss any health and fitness concerns related to abnormal readings and educate clients on strategies to reduce personal risk and improve overall health.

Consistency in location and technique is crucial for tracking progress. Key measurements include abdominal, hip, waist, biceps, and midthigh circumference, each taken with the client standing in specific positions. Following these guidelines will enable trainers to accurately monitor clients’ progress and adjust their training programs appropriately.

Waist-to-hip ratio

The Waist to Hip Ratio (WHR) is an important measurement when assessing health risks associated with excess body fat. Research suggests that the distribution of fat deposits might be a better indicator of disease risk than overall body fat (Jensen et al., 2013). WHR helps differentiate between android (apple-shaped) and gynoid (pear-shaped) individuals. Apple-shaped individuals carry excess fat in the abdominal area, while pear-shaped individuals have excess fat in the hips and thighs.

Although any excess fat weight is detrimental to health, android individuals with a high WHR face greater health risks. To calculate a client’s WHR, divide the waist measurement by the hip measurement. The resulting ratio helps determine the relative risk ratings for health issues associated with body fat distribution. By understanding and monitoring WHR, personal trainers can better tailor exercise programs to address clients’ specific health risks and improve overall well-being.

Body Composition Analysis

Body composition analysis determines the relative percentages of body weight from fat and fat-free body tissue or Lean Body Mass (LBM). These measurements are much more important to an individual’s overall health than simply body weight. Body weight, without any knowledge of an individual’s body composition, cannot indicate relative health risk or even the level of obesity. It is the excess body fat that leads to obesity and the risk of heart disease. Excess body fat on the upper body around the waist area is essential. Body fat around the waist has been shown to have the highest correlation with an increased risk of heart disease.

There are many methods for body composition measurements, some more accurate than others, but all of them have in common that they are so-called indirect measurement methods. For example, we cannot directly measure body fat or Lean Body Mass; every measure we make will therefore be an estimate of different components that make up our body. Hydrostatic weighing, also known as underwater weighing or hydro densitometry, is one of the most accurate ways to measure body fat but still relies on methodological calculation models to estimate body composition. It was considered the gold standard for measuring body composition until more advanced methods, such as CT scans and MRI scans, were developed (Yetman, 2020).

We will face several issues in personal training while attempting to measure body composition as accurately as possible. The main issue is access to more accurate methods such as CT, MRI, or even DEXA scans. Next to the issue of availability, there is the downside of high cost with the so-called “gold standards” of body composition analysis. Therefore many personal trainers will choose less accurate methods that are just reliable enough. Skinfold testing might be one option, but it requires a lot of practice, and as the PTBA suggests, tools that are less common than plastic calipers are often used in gyms.

In our opinion, there are two more critical aspects of skinfold testing you must be aware of as a personal trainer:

1) It is one of the most invasive measurements

2) It will be largely inaccurate with higher body fat percentages

We’re not saying you shouldn’t be using caliper testing at all, but you should be cautious with which type of clients that method is more suitable.

Regardless of which method you choose, we suggest you use the Body Composition measurements to follow the trend of changes occurring in the body while improving nutrition and mastering all components of fitness. We will explain more about the different methods you can use to choose the most suitable one for your clients.

Skinfold testing

Commonly called caliper testing, skinfold measurements were especially popularized through the teachings of the Strength and Conditioning legend Charles Poliquin. Poliquin was ahead of the industry in many respects and provided valuable views on training and nutrition interventions. Not all of them were science-based, and some turned out to be hugely controversial. At the same time, his positive influence on the strength and conditioning world as the fitness world, is undeniable.

When searching for the most precise technique of skinfold measurements, we suggest looking out for ISAK-accredited courses on anthropometry. However, the technique we provide in this book is considered a more basic approach that might be useful to personal trainers in everyday circumstances.

This technique involves using special calipers to pinch various body parts to measure subcutaneous fat found just beneath the skin. The principle behind skinfold testing is based on the established relationship between subcutaneous fat and total body fat (Heyward, 1991). By measuring the thickness of fat under the skin, it is possible to estimate the overall body fat percentage. Skinfold measurements can yield reasonably accurate results when performed correctly. When executed accurately, they can correlate well with body fat percentage measurements obtained through hydrostatic weighing—within about 3-5%. However, such accuracy can be achieved by following strict testing protocols and constant practice. We would estimate that a higher accuracy rate is achieved beyond 5.000 measurements performed and testing with calipers constantly.

However, skinfold testing has several limitations. For instance, this method does not measure visceral fat, the fat surrounding internal organs. Additionally, the accuracy of skinfold testing can be affected by variations in how individuals perform the pinching technique. Therefore, to minimize this error, it is advisable to have the same person consistently perform the test (Cannon, 2011).

There is a potential risk of obtaining inaccurate, misleading, and unreliable results from caliper measurements. If errors occur in the equations used, the measurements are taken poorly, or the consistency of the measurements is impaired, the outcome can lead to disappointment, frustration, and demotivation for both personal trainers and their clients (PTdirect, 2023). Therefore, again, we highly recommend an ISAK-accredited course for anthropometry to learn the precise protocols for skinfold testing.

There are various methods for caliper testing. Therefore, the number of sites commonly used for skinfold measurements in determining body composition will also vary. As we mentioned, different tools are also available to take the measurements. In our opinion and through years of practice, we found the most accurate measurement tool is the Harpenden Skinfold Caliper. Therefore, we encourage you to use the Harpenden caliper. For general practice, we will show four sites used in the Durnin and Womersley test (1974) for simplification purposes.

Procedures

• Take all skinfolds on the right side of the body (for reliability).

• The pinch should include two thicknesses, one of skin and one of the subcutaneous fat, but no muscle or fascia.

• Place the contact surface of the calipers at a 90-degree angle to the skinfold approximately 1 cm below the fingers. Slightly release the pressure between the fingers, but remain to hold the skinfold so that the caliper apply greater pressure. Release the caliper handle and read the needle to the nearest 0.1mm approximately 4 seconds after the pressure is released. 

• Keep the fold elevated while the measurement is recorded

• Take at least three measurements at each site, and calculate the mean value for use in the equation. Retest if the second measurement is not within 1 mm of the first measurement.

• Skinfold measurements should not be taken when the skin is wet or after exercise.

• Find the percent body fat based on age, sex, and skinfold total below.

The following images and instructions will help you to locate the four sites used in the Durnin and Womersley test. Once you have successfully located the sites, use the previous instructions on how to take a skinfold to complete the four-site test. Locating the exact same measurement point with every follow-up measurement is crucial to the consistency of the results.

Tricep Skinfold

-Vertical fold

-Located on the posterior midline of the upper arm

-Measure halfway between the acromion (bony point of the shoulder) and olecranon processes (bony point of the elbow)

-Arm held freely to the side of the body

Subscapular Skinfold

-Diagonal fold

-Located 1 to 2 cm below the inferior angle of the scapula (the bottom of the shoulder blade)

-If you struggle to locate the bottom of the shoulder blade then ask your client to raise their arm up behind their back – this should make the scapula become more prominent.

Subscapular Skinfold

-Diagonal fold

-Located 1 to 2 cm below the inferior angle of the scapula (the bottom of the shoulder blade)

-If you struggle to locate the bottom of the shoulder blade then ask your client to raise their arm up behind their back – this should make the scapula become more prominent.

Suprailiac Skinfold

-Diagonal fold

-Located 1 cm above the anterior superior iliac crest (top of the hip bone)

-Locating this landmark may require you to ‘poke’ firmly through thick subcutaneous layers of fat to find the bone underneath.

Bioelectrical Impedance (BIA) and DEXA Scan

Bioelectrical Impedance Analysis (BIA) and Dual-Energy X-ray Absorptiometry (DEXA) are commonly used to assess body composition. Both techniques provide valuable information, but they differ in accuracy and the type of data they offer.

Bioelectrical Impedance Analysis (BIA) BIA measures body composition by sending a low-level electrical current through the body and measuring the resistance encountered. The resistance is then used to estimate the amount of body fat, lean body mass, and total body water. BIA devices are typically affordable and widely accessible, making them popular for personal trainers and fitness centers. However, BIA is less accurate than DEXA, as it can be affected by factors such as hydration levels, food intake, and recent physical activity.

Hydration status changes can significantly affect body tissue’s electrical conductivity, leading to variations in the results obtained from BIA (Lukaski, 1987). Despite its limitations, BIA can still be regarded as a helpful tool for estimating body composition, especially when ease of administration is a priority (Institute of Medicine 2012).
The more accurate devices are becoming expensive and offer many extra features.

Dual-Energy X-ray Absorptiometry (DEXA) is considered the gold standard for body composition analysis, providing highly accurate fat mass, lean mass, and bone mineral density measurements. DEXA uses X-ray technology to scan the entire body and generate a detailed report on body composition. Although DEXA is more accurate than BIA, it is also more expensive. It requires specialized equipment, usually not available in fitness centers. Certain larger health clubs will provide these measurements, although we have yet to find such health clubs.

Both BIA and DEXA measurements can be influenced by the body’s water retention, which is connected to nutrition and physical activity before the assessments. Therefore, to ensure accurate and consistent results, it is crucial to perform these measurements separately from training sessions and under the same conditions (e.g., same day, same time, and consistent nutrition habits).

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