Introduction: Exercise therapy (ET) is advocated as a treatment for chronic nonspecific low back pain (CNSLBP). However, therapy effect sizes remain low. In other chronic disorders, training at higher intensity has resulted in greater improvements on both general health related and disease specific outcomes compared to lower-intensity ET. Possibly, high-intensity training also improves effect sizes in CNSLBP. Objective: To compare the effects of a high-intensity ET program with a similar moderate-intensity ET program on disability, pain, function, exercise capacity, and abdominal/back muscle strength in persons with CNSLBP. Methods: In a randomized controlled trial, persons with CNSLBP performed a 12-wk ET program (24 sessions, 1.5 h per session, twice per week) at high-intensity training (HIT) or moderate-intensity training (MIT). Questionnaires to assess disability (Modified Oswestry Index [MODI]), pain intensity (Numeric Pain Rating Scale), and function (Patient Specific Functioning Scale), a cardiopulmonary exercise test to assess exercise capacity (V˙O_2max, cycling time), and a maximum isometric muscle strength test to assess abdominal/back muscle strength (maximum muscle torque) were administered at baseline and after the training program. Results: Thirty-eight participants (HIT: n = 19, MIT: n = 19) were included (mean age, 44.1 yr, SD = 9.8, 12 males). Groups did not differ at baseline. Between group differences (P < 0.01) in favor of HIT were found for MODI, V˙O_2max, and cycling time. Within group improvements (P < 0.01) were found in both groups on MODI (HIT:−64%, MIT:−33%), Numeric Pain Rating Scale (HIT, −56%; MIT, −39%), Patient-Specific Functioning Scale (HIT:+37%, MIT:+39%), V˙O_2max (HIT:+14, MIT:+4%), cycling time (HIT:+18%, MIT:+13%), and back muscle strength (HIT:+10%, MIT:+14%). Conclusions: High-intensity training proved to be a feasible, well tolerated, and effective therapy modality in CNSLBP. Moreover, it shows greater improvements on disability and exercise capacity than a similar ET performed at moderate intensity.

Agten A, et al. Anat Cell Biol. 2020 Jan;53:e14. https://doi.org/10.5115/acb.20.009

High-intensity training (HIT) improves rehabilitation outcomes such as functional disability and physical performance in several chronic disorders. Promising results were also found in chronic nonspecific low back pain (CNSLBP). However, the impact of different exercise modes on HIT effectiveness in CNSLBP remains unclear. Therefore, this study evaluated the effectiveness of various HIT exercise modes and compared differences between these modes, on pain intensity, disability, and physical performance, as a therapeutic intervention for persons with CNSLBP. In a randomized comparative trial, consisting of a 12-week program, persons with CNSLBP were divided into four HIT groups, i.e., cardiorespiratory interval training coupled with either general resistance training, core strength training, combined general resistance and core strength training, or mobility exercises. Before and after the program, the Numeric Pain Rating Scale (NPRS), Modified Oswestry Disability Index (MODI), and Patient Specific Functioning Scale (PSFS) were recorded, and a cardiopulmonary exercise test (VO₂max, cycling time) and isometric trunk strength test (maximum muscle torque) were performed. Eighty participants (mean age: 44.0 y, 34 males) were included. Improvements were found within all groups after the HIT programs and ranged from −39 to −57% on the NPRS, +27 to +64% on the MODI, +38 to +89% on the PSFS, +7 to +14% on VO₂max, and +11 to +18% on cycling time. No differences between groups were found. High-intensity cardiorespiratory interval training improves CNSLBP rehabilitation outcomes when performed with other HIT exercise modes or mobility exercises. Hence, when setting up an exercise therapy program in CNSLBP rehabilitation, various HIT modes can be considered as therapy modalities.