Background : Currently, very little is known about the effects of an endurance high intensity interval training (HIIT) in chronic low back pain patients. Therefore, the feasibility and safety of the HIIT must be assessed first before Currently, very little is known about the effects of an endurance high intensity interval training in chronic low back pain patients. Therefore, the feasibility and safety of the HIIT has to be assessed first before it can be integrated safely into research and daily practice it can be integrated safely into research and daily practice. This study aims to answers the question if high intensity interval training and moderate intensity continuous training (MICT) have comparable adherence and feasibility. Methods : Participants (age from 29 to 69 years) with non-specific chronic low back pain were recruited in this randomised, single-blinded, allocation concealed, feasibility study. The participants trained 30 min on a cycle ergometer for 12 weeks. One group had HIIT and the other MICT. Results : Of 45 screened subjects 30 participated. The adherence rate was 94% in the HIIT group (median 0.94, IQR 0.23) versus 96% in the MICT group (median 0.96, IQR 0.08), without between-group differences: estimated median of the difference of − 0,01 [95% CI, − 0.11 to 0.06; p = 0.76]. Similar results in enjoyability (median 3, IQR 1 vs median 2, IQR 1.8) and willingness to continue the training (median 3, IQR 1 vs median 3, IQR 0.4). Both groups improved in pain and disability, without between-group differences in pain [median of the difference, 0.5; 95% CI, − 1 to 2; p = 0.95] nor in disability [median of the difference, 1.78; 95% CI, − 6.44 to 9.56; p = 0.64]. Conclusion : There were no differences in adherence rates. HIIT is as feasible as MICT in non-specific chronic low back pain and can be used in future larger trials to deepen the knowledge about HIIT in this specific population.