Why ISAK Body Composition Is More Than Skinfold Testing

A lot of people hear “ISAK” and immediately think skinfold testing. But ISAK (International Society for the Advancement of Kinanthropometry) is much more than that.

Instead of focusing only on body fat, ISAK protocols combine skinfolds with girths, lengths, and breadths. At Level 2, practitioners use validated equations to estimate fat, muscle, bone, and residual mass with impressive accuracy. A 2024 study in Scientific Reports by Rojano-Ortega and colleagues showed these equations predict skeletal muscle mass with correlations over 0.90, closely matching DEXA results.

For coaches, dietitians, and sports professionals, this has very practical value. Strength coaches can use ISAK to set functional playing weights based on bone structure and body proportions, which can help reduce injury risk. Dietitians and diet techs can track changes in muscle and fat more precisely when DEXA isn’t available, something Baglietto and colleagues (2024) highlighted in Frontiers in Nutrition. And in sport-specific settings, ISAK has been used to build athlete profiles, like the soccer standards published by Petri et al. (2024).

DEXA remains the gold standard for bone density and regional fat distribution, but ISAK fills a gap by offering standardized, reproducible field measurements. Together, they provide a much fuller picture of body composition.

Takeaway: ISAK isn’t just about skinfolds. It’s a practical and validated system that can guide performance, nutrition, and injury prevention in a way that simple fat percentage testing cannot.

References

Baglietto, N., et al. (2024). Assessing skeletal muscle mass and lean body mass via ISAK anthropometry and comparison with DEXA. Frontiers in Nutrition, 11, 1445892. https://doi.org/10.3389/fnut.2024.1445892

Petri, C., Campa, F., Holway, F., Pengue, L., & Arrones, L. S. (2024). ISAK-based anthropometric standards for elite soccer players. Sports, 12(3), 69. https://doi.org/10.3390/sports12030069

Rojano-Ortega, D., Moya-Amaya, H., Molina-López, A., Berral-Aguilar, A. J., & Berral-de la Rosa, F. J. (2024). Development and validation of a new anthropometric equation to predict skeletal muscle mass in a heterogeneous Caucasian population. Scientific Reports, 14, 28646. https://doi.org/10.1038/s41598-024-77965-8