Optimizing physical fitness in chronic stroke patients: the impact of exercise training modality and dosage on maximal and sub-maximal fitness - a systematic review and meta-analysis.

Only immediate post-intervention results were used; the review excluded follow-up data, so it says nothing about whether gains last. The 45-minute, three-times-a-week, eight-week dose is descriptive. The analysis that actually tested total training time against effect size found no significant relationship. Training protocols applied the frequency, intensity, time and type principles inconsistently, and some pooled analyses were highly heterogeneous. 91% of the included trials were rated high risk of bias for blinding of participants and personnel, which is hard to avoid in exercise trials but still weakens them. Two of the 38 trials could not be pooled because means or standard deviations were missing. Resistance training was represented by only four trials and mixed training by five, so those subgroup results rest on very few studies. Participants averaged between 44 and 75 years old and most trials were run in developed countries, which limits how far the findings travel. Selection criteria and missing data may have left out contextual factors such as participant motivation.

The authors declared no conflicts of interest. The study received no specific funding; open-access fees were covered by the institution.

Do not treat 45 minutes, three times a week for eight weeks as a proven dose. The paper's own test of total training time found no significant link to effect size, so this describes which trials happened to do best, not a threshold that causes improvement.