Objective: The aim of this study was to compare the effect of 4 hours of sitting interrupted with hourly bouts of standing and/or pedaling versus uninterrupted sitting on alertness and discomfort among sedentary office workers.
Methods: Fifteen middle-aged sedentary workers were randomized to three 4-hour conditions: (1) uninterrupted sitting; (2) sitting interrupted with 10 minutes of standing/hour; and (3) sitting interrupted with 10 minutes of pedaling/hour. Self-reported measures of alertness and discomfort were collected.
Results: Uninterrupted sitting significantly increased discomfort (P < 0.001). Discomfort was lower in both the standing (P < 0.001) and pedaling (P < 0.001) conditions than the uninterrupted sitting condition. Short-lived improvements in alertness were observed immediately following several standing (50%) and pedaling (100%) interruptions.
Conclusion: Prolonged sitting increases discomfort while brief standing and pedaling interruptions attenuate impairments in discomfort among sedentary workers.