Ultrasound-Based Assessment of Subcutaneous Adipose Tissue Changes During a 7-Day Ultramarathon: Association with Anthropometric Indices, Not Body Mass

Ultrasound-Based Assessment of Subcutaneous Adipose Tissue Changes During a 7-Day Ultramarathon: Association with Anthropometric Indices, Not Body Mass

Článek WoS

Background: Accurately tracking body-composition changes in endurance field settings remains methodologically challenging. This study aimed to evaluate whether changes in subcutaneous adipose tissue (SAT) across a 7-day ultramarathon are better reflected by anthropometric indices than by body mass (BM) alone. Methods: Twenty ultrarunners were assessed using both anthropometric indices and ultrasound measurements of SAT thickness, applying a novel method that distinguishes layers including (D-I) versus excluding (D-E) embedded fibrous structures. Measurements were obtained before the race and after Stages 4 and 7. Indices included body mass index (BMI), mass index (MII), and waist-to-height ratio (WHtR). Results: Total SAT thickness decreased significantly for both D-I (p = 0.001) and D-E (p < 0.001). BM, BMI, MII, and WHtR also declined significantly post-race (p < 0.001). SAT reduction was most pronounced at the abdominal and thigh sites. Additionally, ultrarunners with lower D-E values exhibited lower fat at the abdomen and distal triceps. BMI was significantly related to D-E at the upper and lower abdomen and erector spinae; MII was significantly associated with D-E at the upper and lower abdomen; and WHtR correlated with both D-E and D-I at abdominal and erector spinae sites. BM showed no significant association with any SAT parameter. Conclusions: Ultrasound-derived SAT thickness, in combination with BMI, MII, and WHtR, offers a field-feasible approach to evaluate body-composition change during multistage ultramarathons. In contrast, BM alone does not reliably reflect SAT distribution or loss.

Background: Accurately tracking body-composition changes in endurance field settings remains methodologically challenging. This study aimed to evaluate whether changes in subcutaneous adipose tissue (SAT) across a 7-day ultramarathon are better reflected by anthropometric indices than by body mass (BM) alone. Methods: Twenty ultrarunners were assessed using both anthropometric indices and ultrasound measurements of SAT thickness, applying a novel method that distinguishes layers including (D-I) versus excluding (D-E) embedded fibrous structures. Measurements were obtained before the race and after Stages 4 and 7. Indices included body mass index (BMI), mass index (MII), and waist-to-height ratio (WHtR). Results: Total SAT thickness decreased significantly for both D-I (p = 0.001) and D-E (p < 0.001). BM, BMI, MII, and WHtR also declined significantly post-race (p < 0.001). SAT reduction was most pronounced at the abdominal and thigh sites. Additionally, ultrarunners with lower D-E values exhibited lower fat at the abdomen and distal triceps. BMI was significantly related to D-E at the upper and lower abdomen and erector spinae; MII was significantly associated with D-E at the upper and lower abdomen; and WHtR correlated with both D-E and D-I at abdominal and erector spinae sites. BM showed no significant association with any SAT parameter. Conclusions: Ultrasound-derived SAT thickness, in combination with BMI, MII, and WHtR, offers a field-feasible approach to evaluate body-composition change during multistage ultramarathons. In contrast, BM alone does not reliably reflect SAT distribution or loss.

endurance performance, anthropometry, subcutaneous adipose tissue, ultrasound assessment, multistage ultramarathon, energy balance

endurance performance, anthropometry, subcutaneous adipose tissue, ultrasound assessment, multistage ultramarathon, energy balance

CHLÍBKOVÁ, D.; KNECHTLE, B.; WEISS, K.; KOVACOVA, I.; ROSEMANN, T.

2026

01.12.2025

MDPI

Journal of Functional Morphology and Kinesiology

10

4

Švýcarská konfederace

1

15

15

https://www.mdpi.com/2411-5142/10/4/467

http://hdl.handle.net/11012/255883