Summary of findings 1. Summary of findings: Exercise treatment compared with no treatment, usual care or placebo for chronic low back pain.

Outcomes	Anticipated absolute effects*		Number of participants (studies; study groups)	Certainty of the evidence (GRADE)a
	Without exercise (no treatment, usual care or placebob)	Difference with exercise
Pain intensity (0‐100; 0 = no pain): Earliest follow‐up (time point closest to 3 months)	The mean pain intensity outcome at follow‐up ranged across the no treatment, usual care or placebo comparison groups from 21 to 81.	The mean pain intensity in the exercise treatment groups was 15 points better than the no treatment, usual care or placebo comparison groups at follow‐up (12 to 18 points better).	Participants = 2746; studies = 35; study groups = 47	⊕⊕⊕⊝ moderatec due to risk of inconsistency
Functional limitations (0‐100; 0 = no functional limitations): Earliest follow‐up (time point closest to 3 months)	The mean functional limitations outcome at follow‐up ranged across the no treatment, usual care or placebo comparison groups from 7 to 58.	The mean functional limitations in the exercise treatment groups was 7 points better than the no treatment, usual care or placebo comparison groups at follow‐up (5 to 8 points better).	Participants = 2942; studies = 38; study groups = 50	⊕⊕⊕⊝ moderated due to potential publication bias
*The anticipated absolute effects without exercise come from the range of outcomes at follow‐up in the no treatment, usual care or comparison groups.
GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of effect. Moderate certainty: We are moderately confident in the effect estimate. The true effect is likely to be close to the estimate of effect, but there is a possibility that it is substantially different. Low certainty: Our confidence in the effect estimate is limited. The true effect may be substantially different from the estimate of effect. Very low certainty: We have very little confidence in the effect estimate. The true effect is likely to be substantially different from the estimate of effect.

^a For all comparisons and outcomes ‐ certainty may be raised to high given that further similar research is very unlikely to change our confidence in the estimate of effect.

^b Observed effects were consistent when we performed a post hoc sensitivity analysis restricting to only placebo‐controlled trials. 

^cSeven studies (10 groups; 526 participants) were judged to have high risk of bias (19% of participant data). Exclusion of these studies in sensitivity analysis did not change conclusions. Serious unexplained inconsistency (substantial heterogeneity I² = 75%, point estimates and confidence intervals varied considerably). No concerns about indirectness or imprecision. No evidence of publication bias (Egger's test, P = 0.30).

^d Nine studies (13 groups; 495 participants) were judged to have high risk of bias (17% of participant data). Exclusion of these studies in sensitivity analysis did not change conclusions. Some unexplained inconsistency (moderate heterogeneity I² = 38%, point estimates and confidence intervals varied). No concerns about indirectness or imprecision. Some evidence of publication bias (Egger's test, P = 0.005).