Long maximal incremental tests accurately assess aerobic fitness in class II and III obese men

This study aimed to compare two different maximal incremental tests with different time durations [a maximal incremental ramp test with a short time duration (8-12 min) (S_Test) and a maximal incremental test with a longer time duration (20-25 min) (L_Test)] to investigate whether an L_Test accurately assesses aerobic fitness in class II and III obese men. Twenty obese men (BMI ≥35 kg·m-2) without secondary pathologies (mean±SE; 36.7±1.9 yr; 41.8±0.7 kg∗m^-2) completed an S_Test (warm-up: 40 W; increment: 20 W∗min-1) and an L_Test [warm-up: 20% of the peak power output (PPO) reached during the S_Test; increment: 10% PPO every 5 min until 70% PPO was reached or until the respiratory exchange ratio reached 1.0, followed by 15 W.min^-1 until exhaustion] on a cycle-ergometer to assess the peak oxygen uptake V O_2peak and peak heart rate (HR_peak) of each test. There were no significant differences in V O_2peak (S_Test: 3.1±0.1 L∗min^-1; L_Test: 3.0±0.1 L∗min^-1) and HR_peak (S_Test: 174±4 bpm; L_Test: 173 ±4 bpm) between the two tests. Bland-Altman plot analyses showed good agreement and Pearson product-moment and intra-class correlation coefficients showed a strong correlation between V O_2peak (r=0.81 for both; p≤0.001) and HR_peak (r=0.95 for both; p≤ 0.001) during both tests. V O_2peak and HR_peak assessments were not compromised by test duration in class II and III obese men. Therefore, we suggest that the L_Test is a feasible test that accurately assesses aerobic fitness and may allow for the exercise intensity prescription and individualization that will lead to improved therapeutic approaches in treating obesity and severe obesity.