We included 29 trials (926 participants); 27 included children and adolescents up to the age of 19 years, three included adolescents and young adults (10 to 22 years), and one included adults over 20 years. Males constituted 53% of the sample. Five trials were conducted in the USA; four in Australia; two in Egypt, Korea, Saudi Arabia, Taiwan, the Netherlands, and the UK; three in Greece; and one apiece in India, Italy, Norway, and South Africa.
Twenty-six trials included people with spastic CP only; three trials included children and adolescents with spastic and other types of CP. Twenty-one trials included people who were able to walk with or without assistive devices, four trials also included people who used wheeled mobility devices in most settings, and one trial included people who used wheeled mobility devices only. Three trials did not report the functional ability of participants. Only two trials reported participants’ manual ability. Eight studies compared aerobic exercise to usual care, while 15 compared resistance training and 4 compared mixed training to usual care or no treatment. Two trials compared aerobic exercise to resistance training. We judged all trials to be at high risk of bias overall.
We found low-quality evidence that aerobic exercise improves gross motor function in the short term (standardised mean difference (SMD) 0.53, 95% confidence interval (CI) 0.02 to 1.04, N = 65, 3 studies) and intermediate term (mean difference (MD) 12.96%, 95% CI 0.52% to 25.40%, N = 12, 1 study). Aerobic exercise does not improve gait speed in the short term (MD 0.09 m/s, 95% CI −0.11 m/s to 0.28 m/s, N = 82, 4 studies, very low-quality evidence) or intermediate term (MD −0.17 m/s, 95% CI −0.59 m/s to 0.24 m/s, N = 12, 1 study, low-quality evidence). No trial assessed participation or quality of life following aerobic exercise.
We found low-quality evidence that resistance training does not improve gross motor function (SMD 0.12, 95% CI −0.19 to 0.43, N = 164, 7 studies), gait speed (MD 0.03 m/s, 95% CI −0.02 m/s to 0.07 m/s, N = 185, 8 studies), participation (SMD 0.34, 95% CI −0.01 to 0.70, N = 127, 2 studies) or parent-reported quality of life (MD 12.70, 95% CI −5.63 to 31.03, n = 12, 1 study) in the short term. There is also low-quality evidence that resistance training does not improve gait speed (MD −0.03 m/s, 95% CI −0.17 m/s to 0.11 m/s, N = 84, 3 studies), gross motor function (SMD 0.13, 95% CI −0.30 to 0.55, N = 85, 3 studies) or participation (MD 0.37, 95% CI −6.61 to 7.35, N = 36, 1 study) in the intermediate term.
We found low-quality evidence that mixed training does not improve gross motor function (SMD 0.02, 95% CI −0.29 to 0.33, N = 163, 4 studies) or gait speed (MD 0.10 m/s, −0.07 m/s to 0.27 m/s, N = 58, 1 study) but does improve participation (MD 0.40, 95% CI 0.13 to 0.67, N = 65, 1 study) in the short-term.
There is no difference between resistance training and aerobic exercise in terms of the effect on gross motor function in the short term (SMD 0.02, 95% CI −0.50 to 0.55, N = 56, 2 studies, low-quality evidence).
Thirteen trials did not report adverse events, seven reported no adverse events, and nine reported non-serious adverse events.