Author(s): BOLDRINI, M., SANTANGELO, D., NALON, D., MANENTE, A., DE DONATO, S., COSENTINO, E., MARCANTONI, L., FORMENTI, D., CASTIGLIONI, P., RONCHETTI, D., MERATI, G., Institution: UNIVERSITÀ DEGLI STUDI DELL’INSUBRIA, Country: ITALY, Abstract-ID: 2746

INTRODUCTION:
Accurate body composition assessment is crucial in power sports such as the new discipline named “streetlifting”, where performance is strongly influenced by the ratio between fat-free mass and total body weight. Field techniques commonly used in athletic settings include bioelectrical impedance analysis (BIA) and skinfold thickness (SKF), but their agreement in highly trained strength athletes remains uncertain. The aim of this study was to compare BIA and SKF methods in competitive streetlifting athletes during an official contest and determine their level of agreement and interchangeability.
METHODS:
During a national streetlifting competition (Street 4, organized by Streetlifting Italia [SLI]), competitive athletes (n=25) underwent body composition assessment using both BIA (BIVA®PRO, Akern, Italy) and skinfold measurements. Body fat percentage was estimated using standard prediction equations from skinfold thickness and compared with BIA-derived values. Agreement between methods was assessed using paired t-tests, Pearson correlation, and Bland–Altman analysis. Statistical significance was set at p<0.05.
RESULTS:
Body fat estimation by BIA was significantly higher than that obtained from skinfold equations (p<0.001). Bland–Altman analysis showed a mean bias of +9.2% body fat (BIA higher than SKF), with 95% limits of agreement ranging from +1.9% to +16.5%, indicating only moderate agreement between methods. Despite a strong correlation between techniques (r≈0.80; p<0.001), substantial individual variability was observed. BIA systematically overestimated adiposity compared with SKF across the sample, particularly in leaner athletes. These findings suggest that although the two methods are related, they cannot be considered interchangeable in this population, at least during the contest.
CONCLUSION:
In elite streetlifting athletes, BIA and skinfold methods show strong correlation but poor agreement, with BIA significantly overestimating body fat compared with SKF. Given the wide limits of agreement range observed in the Bland–Altman analysis, SKF appears more appropriate for assessing body composition in very lean strength athletes, while BIA remains useful for rapid field screening. Combining both techniques may improve monitoring in strength-sport contexts. Further research using reference methods such as DXA is warranted to confirm validity in this athletic population.