Optimized perioperative care after total hip and knee arthroplasty (THA/TKA) has decreased length of stay (LOS) but data on activity, sleep and cognition after discharge are limited. We included 20 patients ≥60 years undergoing THA/TKA, monitoring them for 3 days preoperatively and 9 days postoperatively with actigraphs for sleep and activity assessment. Pain scores were recorded daily. Cognition was evaluated by 2 cognitive tests. Results showed a mean age was 70.5 years and mean LOS was 2.6 days. Actigraphs showed increased daytime sleep and decreased motor activity postoperatively. Early postoperatively cognitive decline and increased pain returned to preoperative levels by postoperative day (POD) 5–9. Despite the small sample size the study illustrated that post-discharge activity is decreased and daytime sleep is increased after fast-track THA/TKA, while cognition and pain return to preoperative levels by POD 9. Objective assessment of these recovery parameters may be valuable in future interventional studies to enhance recovery after THA/TKA.