Dosage and effectiveness of aerobic training on cardiorespiratory fitness, functional capacity, balance, and fatigue in people with Multiple Sclerosis: a systematic review and meta-analysis.

The study was preregistered in the International Prospective Register of Systematic Review (PROSPERO) with the following registration number: CRD42020199266. OBJECTIVES: To evaluate the benefits of aerobic training (AT) programs on cardiorespiratory fitness, functional capacity, balance, and fatigue in people with MS and to identify the most optimal dosage of AT programs for people with MS via a systematic review with meta-analysis. DATA SOURCES: Two electronic databases were searched until March 2020 (PubMed-Medline and Web of Science). STUDY SELECTION: Studies examining the effect of AT program on cardiorespiratory fitness, functional capacity, balance, and fatigue were included. DATA EXTRACTION: After applying the inclusion and exclusion criteria, 43 studies were included. A total sample of 1070 people with MS [n=680 AT group; n=390 control group (CG)] were analyzed. DATA SYNTHESIS: AT group shows a significant increase in cardiorespiratory fitness [Standardized Mean Difference (SMD)=0.29, p=0.002], functional capacity (Timed Up and Go Test: SMD=-1.14, p<0.001; gait speed: SMD=-1.19, p<0.001 and walking endurance: SMD=0.46, p<0.001), and balance (SMD=3.49, p<0.001) after training. The fatigue perception also decreased (SMD=-0.45, p<0.001). However, no significant differences were observed when compared to the CG in either cardiorespiratory fitness (0.14, p=0.19) or fatigue perception. Nevertheless, significant differences between AT group and CG were observed in balance (p=0.02), gait speed (p=0.02) and walking endurance (p=0.03), favouring the participants who performed AT. Regarding the subgroup analysis, no significant differences were observed between subgroups in any of the variables studied except for gait speed, in which a greater increase in post-training was observed when AT program applied the continuous method (χ2=7.75, p=0.005) and the exercises were performed by walking (χ2=9.36, p=0.002). CONCLUSIONS: Aerobic training improves gait speed, walking endurance and balance. Cardiorespiratory fitness and fatigue perception also improved after AT, but no differences were found with CG. In addition, subgroup analysis suggested that training using continuous and walking methods could optimize gait speed.