Pain intensity and pain sensitivity are not increased by a single session of high-intensity interval aerobic exercise in individuals with chronic low back pain: A randomized and controlled trial.

BACKGROUND:Evidence on the acute impact of high-intensity interval aerobic exercise on pain is scarce. This type of exercise might be perceived as increasing pain intensity and pain sensitivity negatively impacting adherence. More evidence on the acute effects of high-intensity interval aerobic exercise in individuals with low back pain (LBP) is needed. OBJECTIVES:To compare the acute effects of a single session of high-intensity interval aerobic exercise, continuous moderate-intensity aerobic exercise, and no exercise on pain intensity and pain sensitivity in patients with chronic non-specific LBP. DESIGN:Randomized controlled trial with three arms. METHOD:Participants were randomly assigned to one of three groups (i) continuous moderate-intensity aerobic exercise, ii) high-intensity interval aerobic exercise, and iii) no intervention. Measures of pain intensity and pressure pain threshold (PPT) at the lower back and at a distant body site (upper limb) were taken before and after 15 min of exercise. RESULTS:Sixty-nine participants were randomized. A significant main effect of time was found for pain intensity (p = 0.011; η2p = 0.095) and for PPT at the lower back (p < 0.001; η2p = 0.280), but not a time versus group interaction (p > 0.05). For PPT at the upper limb, no main effect of time or interaction was found (p > 0.5). CONCLUSIONS:Fifteen minutes of high-intensity interval aerobic exercise does not increase pain intensity or pain sensitivity compared to both moderate-intensity continuous aerobic exercise and no exercise, suggesting that high-intensity interval aerobic exercise can be used in clinical practice and patients reassured that it is unlikely to increase pain.