Recent acute studies have shown that high‐intensity resistance circuit‐based (HRC) training in hypoxia increases metabolic stress. However, no intervention studies have yet proven their effectiveness. This study aimed to analyze the effect of 8 weeks of HRC in hypoxia on aerobic performance, resting energy expenditure (REE), repeat sprint ability (RSA) and hematological variables. Twenty‐eight subjects were assigned to hypoxia (FiO2 = 15%; HRChyp: n = 15; age: 24.6 ± 6.8 years; height: 177.4 ± 5.9 cm; weight: 74.9 ± 11.5 kg) and normoxia (FiO2 = 20.9%; HRCnorm: n = 13; age: 23.2 ± 5.2 years; height: 173.4 ± 6.2 cm; weight: 69.4 ± 7.4 kg) groups. Each training session consisted of two blocks of three exercises (Block 1: bench press, leg extension, front pull down; 2: deadlift, elbow flexion, ankle extension). Each exercise was performed at 6 repetitions maximum. Participants exercised twice weekly for 8 weeks and before and after the training program blood test, REE, RSA and treadmill running test were performed. Fatigue index in the RSA test was significantly decreased in the HRChyp (−0.9%; P < .01; ES = 2.75) but not in the HRCnorm. No changes were observed in REE and hematological variables. Absolute (4.5%; P = .014; ES = 0.42) and relative (5.2%; P = .008; ES = 0.43) maximal oxygen uptake (VO2max), speed at VO2max (4%; P = .010; ES = 0.25) and time to exhaustion (4.1%; P = .012; ES = 0.26) were significantly increased in HRChyp but not in the HRCnorm. No significant differences between groups were found. Compared with normoxic conditions, 8 weeks of HRC training under hypoxic conditions efficiently improves aerobic performance and RSA without changes in REE and red blood O2‐carrying capacity.