Long periods of inactivity during hospitalization can result in postdischarge deconditioning, potentially leading to disability, readmission, morbidity, and mortality. Research shows that physical activity can mitigate functional decline in hospitalized older adults. A systematic review and meta-analysis were undertaken to determine the optimal dose and type of physical activity to improve functional capacity and reduce adverse events in acutely hospitalized older adults.

Nineteen randomized controlled trials with a total of 3,842 participants who were age 50 or older and admitted to an ICU or to general units with an acute medical condition were included in the review.

An inverted U-shaped dose-response relationship was found between increasing energy expenditure (that is, dose) and functional capacity. The minimal effective dose to improve functional capacity was estimated at approximately 100 metabolic equivalents of task minutes per day (METs min/day), which is equivalent to approximately 40 minutes per day of light effort activities or 25 minutes per day of moderate effort activities. The optimal effective dose was estimated at 159 METs min/day, or approximately 70 minutes per day of light effort activities or about 40 minutes per day of moderate effort activities.

Ambulation was superior to other types of physical activity. The minimal effective ambulation dose was estimated to be 74 METs min/day (approximately 25 minutes of slow walking), and the optimal dose was estimated to be 143 METs min/day (approximately 50 minutes of slow walking).

The rate of adverse events was lower in the active intervention groups than in the usual care group.

According to the authors, their findings suggest that hospitals should promote physical activity among older adults who are hospitalized. They observe that walking may be the simplest intervention to implement in the hospital setting. The authors also note that only patients able to move on their own were included in the studies, follow-up data were limited, and half the studies included were classified as having a high risk of bias.