Association Between the “Weekend Warrior” Physical Activity Pattern and Musculoskeletal Health Outcomes: A Systematic Review

Background: Musculoskeletal conditions impose an increasing health burden, particularly in ageing populations. For adults who find it difficult to exercise throughout the week, completing the recommended amount of moderate-to-vigorous physical activity (MVPA) over only 1–2 days, commonly described as the “weekend warrior” (WW) pattern, may offer a more practical approach. Whether this concentrated pattern is associated with musculoskeletal outcomes comparable to those observed with regularly distributed activity remains uncertain. This systematic review synthesized current evidence concerning the relationships of the WW pattern with musculoskeletal outcomes and examined how these associations compared with those observed in inactive (IA) and regularly active (RA) adults. Methods: PubMed, Web of Science, and Scopus were searched from database inception through 30 June 2026, following PRISMA recommendations. Ten observational investigations, including four cohort and six cross-sectional studies, were eligible, with individual sample sizes ranging from 3539 to 83,376 adults. Cohort studies were evaluated using the Newcastle–Ottawa Scale, whereas cross-sectional studies were appraised with the Agency for Healthcare Research and Quality checklist. Results: Across the included studies, adults following a WW pattern generally had more favorable estimates for low bone mineral density (BMD), osteoporosis, osteoarthritis, spinal degenerative changes, inflammatory arthritis, and sarcopenia than inactive adults. Where WW and RA patterns were directly contrasted, their associations with most musculoskeletal outcomes were broadly similar, although WW was associated with a higher hazard of osteoarthritis in one study, a lower hazard of fractures in another, and lower odds of sarcopenia among WW participants. Subgroup analyses further suggested that these associations may vary across population characteristics, although the patterns were not uniform. Associations with BMD tended to be more pronounced in men and in participants with body mass index (BMI) < 25 kg/m2. Findings for osteoporosis varied according to age and genetic susceptibility, while age- and sex-specific associations with sarcopenia differed across studies. One exploratory analysis also suggested that the association with osteoporosis may vary according to the timing of MVPA across the day. Conclusions: Meeting the recommended weekly amount of MVPA over 1–2 days was generally associated with more favorable musculoskeletal outcomes than inactivity, while the observed estimates were often close to those reported for regularly distributed activity. These findings support the possibility that achieving sufficient weekly activity may remain relevant even when exercise is concentrated into fewer days. Nevertheless, the evidence is entirely observational and is limited by heterogeneous definitions of WW, differences in physical activity assessment, residual confounding, overlapping study populations, and insufficient investigation of injury outcomes. Current findings therefore cannot establish causality or demonstrate equivalence or non-inferiority between WW and RA patterns.