PURPOSE:: Overweight and obese subjects often perceive increased breathlessness during minor exertion and therefore avoid exercise. Respiratory muscle endurance training (RMET) can reduce the perception of breathlessness. We hypothesized that RMET one month prior to and during a 6-month (3months supervised + 3months unsupervised) exercise and nutrition counseling program (EN) would improve the benefits of EN. METHODS:: 26 overweight and obese subjects with significant perception of breathlessness during exercise (age: 33+/-9y; body mass index [BMI]: 31.3+/-4.9kg.m) were randomized to RMET+EN (R+EN) or EN alone. R+EN performed 30min of normocapnic hyperpnea 5wk prior to and 2wkduring EN. EN consisted of two strength and three endurance training sessions per week, as well as prescribed nutritional composition and a 2.1kJ (=500kcal) energy deficit per day. Both groups had an equal number of lab visits during the 7 months. Before, and after 4 and 7 months, subjects performed a 12-min time trial (TT; 6+6min, 2min pause) and an incremental cycling test (ICT) to exhaustion and blood lipids were assessed. RESULTS:: Weight loss was significant and similar in both groups (-4.2 vs -3.7kg; both p<0.05). During the first 4 months, distance covered in 12min improved more (p<0.05) with R+EN (1678 vs 1824m; p<0.001) than with EN alone (1638 vs 1698m; p<0.05), while after R+EN, breathlessness during the ICT was reduced. Blood lipids of the pooled group improved in those subjects with pathologic values before the study. Despite reduced training compliance during the unsupervised period, subjects of both groups maintained the benefits attained during the supervised period. CONCLUSION:: R+EN improved TT-performance more than EN alone, despite similar weight loss, possibly due to reduced perception of breathlessness.