Background
Chronic mechanical low back pain (CMLBP) is one of the most prevalent and costly disorders. Determining its most effective treatment approach is a priority for researchers.

Purpose
To examine the effects of including aerobic exercise within a conventional therapy regimen for young adults with CMLBP.

Methods
Fifty CMLBP patients (22 males and 28 females) were randomly and equally assigned to one of two groups to receive the prescribed treatment for 8 weeks. The control group received the traditional program only (infrared, ultrasound, burst TENS, and exercises); for the experimental group, an aerobic training program using a stationary bicycle was added. Back pain intensity was the primary outcome. Secondary outcomes included the Oswestry disability index, back extensor endurance measured by the Sorensen test, and physical performance indicated by the back performance scale and the 6-min walk test. A Two-way MANOVA was used for data analysis.

Results
Multivariate tests revealed statistically significant effects of group (p = 0.002, partial η2 = 0.182), time (p < 0.001, partial η2 = 0.928), and group-by-time interaction (p = 0.01, partial η2 = 0.149). Univariate group-by-time interactions were significant for back disability (p = 0.043), extensor endurance (p = 0.023) and results of the 6-min walk test (p = 0.023) showing greater improvement in the experimental group. However, back pain intensity and the back performance scale revealed no significant group-by-time interactions. Within-group comparisons were significant for all measured variables in both groups (p < 0.001).

Conclusion
Although a traditional program of infrared, ultrasound, TENS, and exercises is beneficial for CMLBP treatment, adding aerobic exercises to the program leads to more beneficial outcomes.