Inter-methods agreement for the assessment of percentage of body fat between two laboratory methods in male adolescent cyclists

Objective:
To examine inter-methods agreement between dual energy X-ray absorptiometry (DXA) and air displacement plethysmography (ADP) in male adolescent cyclists for assessing percentage of body fat (PBF).

Methods:
PBF of 24 male adolescent cyclists was assessed by DXA and ADP. Agreement between ADP and DXA was determined according to a Bland-Altman plot; validity and lack of agreement was assessed by calculating inter-methods difference. The limits of agreement and differences between methods were also calculated by paired t-tests. Heteroscedasticity was also examined. Results: The values obtained by DXA were higher than those obtained by ADP, and the graph presented heteroscedasticity (both p <0.05; r = 0.74).

Conclusion:
DXA and ADP methods were not comparable in terms of PBF assessment in our sample of male adolescent cyclists; it needs to be taken into account when evaluating longitudinal changes in this determined population.