Effect of muscle training in adolescents and young adults with down syndrome: a systematic review and meta-analysis.

Does resistance-type muscle training help adolescents and young adults with Down syndrome get stronger? This systematic review and meta-analysis pooled eight randomized controlled trials with 266 participants, comparing progressive strengthening exercise programs against usual daily activity, to see the effect on limb strength. Across the pooled studies, muscle training showed a moderate positive effect on strength (standardized mean difference, SMD, of 0.67), with a larger effect for the lower limbs (SMD 0.75). The intervention combining isokinetic training with conventional physical therapy showed the largest effect (SMD 1.24). Training duration did not change the overall result, though longer programs showed more consistent findings across studies (no statistical heterogeneity).

The authors note that larger studies with standardized outcome measures are still needed, especially for young adults dealing with early aging-related changes.

If you or someone you know has Down syndrome and is wondering whether structured strength training helps build muscle power, this review looked at that question. Researchers combined results from eight clinical trials involving 266 adolescents and young adults with Down syndrome, comparing progressive strength exercise programs to regular daily activity. Overall, the pooled evidence showed a moderate improvement in strength with training, with a bigger benefit seen in leg strength than arm strength.

The most effective approach combined a specialized machine-based training method (isokinetic training) with standard physical therapy. How long the programs lasted did not change the overall improvement, but longer programs tended to give more consistent results between studies. It's worth knowing this is based on only eight trials, and the authors themselves say larger studies with more standardized ways of measuring strength are still needed, particularly for young adults who may experience earlier age-related physical changes.

No safety information was reported in this summary.

This is a summary of research, not medical advice. Talk to your own healthcare provider about anything affecting your care.

This systematic review and meta-analysis pooled eight randomized controlled trials (n=266) evaluating progressive resistance training against daily activity controls in adolescents and young adults with Down syndrome, following a PROSPERO-registered protocol. The pooled effect on limb strength was moderate (SMD 0.67), with a stronger effect for lower-limb strength specifically (SMD 0.75) using a random-effects model, appropriate given anticipated between-study variability. The isokinetic training plus conventional physical therapy combination produced the largest single effect (SMD 1.24), though this reflects a subgroup analysis rather than the overall pooled result and should be interpreted with that context in mind.

Training duration did not moderate outcomes, but longer-duration programs were associated with an absence of heterogeneity (I2=0%), suggesting more consistent effects across studies with extended timeframes, while shorter programs showed more inconsistency. With only eight included trials, the evidence base remains limited, and the authors explicitly call for larger-scale studies using standardized strength assessments, particularly in young adults who face premature aging processes. No adverse event data were reported in the abstract.