Skinfold Measurements – are they still relevant in exercise science?

The assessment of body composition is a common practice in the field of exercise science, but there continues to be ongoing debate regarding the most effective tools for this purpose. Skinfold measures, also known as skinfold thickness measurements, are a method used to estimate body composition by measuring the thickness of subcutaneous fat at specific anatomical sites on the body. The measurements are typically taken using calipers, which apply gentle pressure to pinch a double layer of skin and underlying fat. These measurements are then used to estimate the amount of subcutaneous fat, which is an important component of body composition analysis. They do not directly measure other components of body composition, such as muscle mass or visceral fat.

Advantages of Skinfold Measures

Here are a few reasons why skinfold measurements are still relevant in exercise physiology:

1. Non-invasive and practical: Skinfold measurements are a non-invasive and relatively simple method to assess body composition. They do not require complex equipment or sophisticated laboratory settings, making them practical for use in various research settings, clinical settings, and field assessments.
2. Cost-effective: Compared to other methods such as dual-energy X-ray absorptiometry (DXA) or underwater weighing, which can be expensive and require specialized equipment, skinfold measurements are a cost-effective alternative. This affordability makes them more accessible for researchers, practitioners, and individuals interested in body composition analysis.
3. Field-based assessments: Skinfold measurements are particularly valuable in field-based assessments, such as sports teams, fitness centers, or community health programs. These measurements can be easily performed on-site, allowing for frequent monitoring and tracking of body composition changes over time.
4. Longitudinal monitoring: Skinfold measurements provide a practical way to monitor changes in body composition over time. They can be used to assess the effectiveness of exercise interventions, track progress in weight management programs, or monitor changes in body fat distribution during training or rehabilitation.
5. Population-specific considerations: Skinfold measurements have been extensively validated and provide population-specific equations for estimating body fat percentage. This allows for comparisons within specific demographic groups and the application of appropriate reference standards.

While it’s true that more advanced technologies like DXA and bioelectrical impedance analysis (BIA) are available for body composition assessment, skinfold measurements continue to be relevant due to their practicality, cost-effectiveness, and widespread use in exercise physiology and related fields. However, it’s important to note that the choice of measurement method depends on the specific research or clinical context and the desired level of accuracy and precision required for the assessment.

Limitations of Skinfold Measures

While skinfold measurements are widely used and have several advantages, they also have some limitations that need to be considered. Here are a few limitations of skinfold measurements:

1. Accuracy and Precision: The accuracy and precision of skinfold measurements can be affected by various factors, including the skill and experience of the person performing the measurements, the quality of the calipers used, and the variability in skinfold compressibility. Inexperienced or untrained assessors may introduce measurement errors, leading to inaccurate results. Additionally, skinfold measurements may not capture changes in specific fat deposits accurately, as they provide an estimate of subcutaneous fat but do not differentiate between subcutaneous and internal fat.
2. Variability between Measurement Sites: Skinfold measurements are typically taken at specific anatomical sites, such as the triceps, biceps, and subscapular region. However, there can be variability in the fat distribution across individuals, and the chosen measurement sites may not be representative of the overall body fat distribution. This can limit the accuracy of the estimated body fat percentage, especially in populations with atypical fat distribution patterns.
3. Population-specific Equations: Skinfold measurements rely on population-specific equations or prediction equations to estimate body fat percentage. These equations are developed based on specific populations and may not be applicable or accurate for individuals outside of those populations. Therefore, using generalized equations without considering individual characteristics or demographic factors can lead to inaccuracies in body fat estimation.
4. Inter-operator and Intra-operator Variability: Even skilled operators may introduce variability in skinfold measurements due to factors like different application techniques, calibration issues with the calipers, or variations in measurement site identification. Similarly, repeated measurements by the same operator can also have inherent variability, especially if the measurement sites are not consistently identified. As little as a 1 cm difference in the assessed measurement site can have significant effects on the outcome data.
5. Limited Assessment of Regional Fat Distribution: Skinfold measurements provide a global estimate of subcutaneous fat but do not differentiate between fat stored in different regions, such as visceral fat or fat distribution in specific body segments. Therefore, they may not capture changes in regional fat distribution, which can be important in certain clinical or research contexts.
6. Population and Ethnic Differences: Skinfold measurements were primarily developed and validated in specific populations, and their accuracy may vary across different ethnic groups or individuals with unique body composition characteristics. Factors such as skinfold thickness, skin elasticity, and fat distribution patterns can differ, affecting the accuracy of the measurements.
7. Invasiveness and Privacy Concerns: While skinfold measurements are considered non-invasive compared to other methods like DXA or underwater weighing, they still require physical contact and involve partial undressing or exposure of body parts. Some individuals may feel uncomfortable or have privacy concerns related to this aspect of the measurement process.
8. Indirect method: By reporting skinfold measures as a percentage of body fat calculated from regression equations the method it turns an indirect method into doubly indirect. Therefore, it is advisable to discourage the conversion of skinfold thickness into a body fat percentage (BF%) value. Instead, presenting the data as a sum of the eight skinfold sites offers a more accurate and dependable outcome for assessing body composition. This approach provides a clearer and more reliable assessment, ensuring that the measurement focuses solely on the cumulative skinfold thickness across the specified sites.

Despite the limitations associated with skinfold measurements, they can still provide valuable information about changes and trends in body composition when conducted by trained assessors and utilized appropriately within their strengths and weaknesses. It is crucial to interpret the results of skinfold measurements in conjunction with other assessment methods and consider individual factors and limitations to minimize potential errors.

Considering the simplicity, speed, frequency of use, and cost-effectiveness of skinfold measurements, one could argue that they offer an optimal solution for tracking changes in body fat over time, especially when reported as a sum of millimeters rather than a relative percentage value. Moreover, compared to other body composition assessments, skinfold measurements appear to be less affected by challenging factors that are difficult to control in athletes, such as food intake, hydration status, and daily activity. Therefore, it can be concluded that skinfold measurements still hold relevance and can be valuable in the field of sport science.