Thirteen RCTs (n=613) were included in the review. For the meta-analysis, there were 31 study groups (17 exercise and 14 control).
The loss to follow-up ranged from 0 to 67% (21.7 +/- SD 20.4%) in the exercise groups and from 0 to 40% (19 +/- SD 13.8%) in the control groups. Programme compliance (percentage of exercise sessions attended) was reported in less than half of the studies. The median score for study quality was 2 out of a possible 5 points.
A statistically significant mean reduction in TC was reported (2%; -3.4 +/- SE 1.7 mg/dL, 95% CI: -6.7, -0.2), and this had been the trend since 2001. Changes in TC became non significant when further analyses were conducted.
The mean increase for HDL (3%) was statistically non significant, and this had been the trend since 1995. However, there was a statistically significant increase in HDL when studies of postmenopausal women were excluded from the analysis (1.9 +/- SE 0.8 mg/dL, 95% CI: 0.4, 3.4). Increased HDL was also associated with increased VO2 max (p=0.002) and decreased body weight (p<0.001).
The mean reduction in LDL (0.3%) was statistically non significant, and this had been the trend since 2001. Greater decreases in LDL were associated with decreased body weight (p=0.009).
A statistically significant reduction in TG was reported (11%; -16.1 +/- SE 7.3 mg/dL, 95% CI: -30.2, -2.1), and this had been the trend since 2002. Statistical significance remained in further sensitivity analyses.
Publication bias was not statistically significant in any of the above analyses.
Statistically significant reductions were found for body weight (p=0.02) and BMI (-1.1 +/- SE 0.3, 95% CI: -1.8, -0.5), while increases were reported for VO2 max ( p<0.001).