Is the SPARTACUS 15-15 test an accurate proxy for the assessment and tracking of maximal aerobic capacities in adolescents with obesity?

[Purpose] While there is a need for reliable field tests for the evaluation of physical fitness in pediatric obesity, the present work i) evaluates the validity of the Spartacus 15-15 test in indirectly assessing maximal aerobic capacity in adolescents with obesity and ii) evaluates its sensibility to weight loss. [Participants and Methods] Fifty-five 11-16 year-old adolescents with obesity (Tanner 3-4) were enrolled in a 12-week weight-management intervention. Maximal Aerobic fitness (VO(2peak) test + Spartacus test) and body composition (Dual X-ray absorptiometry) were assessed at baseline and after 12 weeks. [Results] Moderate correlations were found at baseline between VO(2peak) (2,231.90 ± 465.6 mL/min) and Spartacus stage (6.83 ± 1.8 stage, r=0.52; p≤0.05), speed (12.85 ± 1.8 km/h, r=0.52 ; p≤0.05) and time (20.6 ± 5.4 min; r=0.50; p≤0.05). The intervention favored significant improvements for VO(2peak), Spartacus Rate of Perceived Exertion final stage, maximal speed and time. Change over time in VO(2peak) and Spartacus variables were not correlated. [Conclusion] The Spartacus test can be used as a proxy for VO(2peak) at baseline and can be used to estimate VO(2peak) using the proposed equation. The Spartacus 15-15 test might be a better indicator for changes in functional capacity than an indicator of VO(2peak) changes in youth with obesity.