A five-minute walking break every hour strikes the best balance between feasibility and effectiveness in mitigating health harms of sitting for long durations, according to a study conducted in real-world settings.

Effects of the brief breaks, which include a boost in mood and lessening of fatigue, do not undermine work performance and suggest that the measures can be included in public health strategy and physical activity guidelines, findings published in the British Journal of Sports Medicine indicate.

Being sedentary for a prolonged time has emerged as a significant public health concern with associated risks including a heightened chance of developing obesity, diabetes and heart disease, among other chronic conditions. Risks can also involve early death.

Researchers, including those from Columbia University Medical Center in the US, said that while brief, regular movement breaks have been proposed as a public health strategy to offset the harms of prolonged sedentary behaviour, real-world viability of the intervention is unclear.

Data of more than 19,300 adults who took part in an interactive 'Body Electric Challenge' organised by the US' National Public Radio (NPR) was analysed.

Nearly 60%, or 11,484, of all the participants -- who spanned across a wide range of ages, occupations and work environments -- took 5-minute walking breaks at a self-selected break frequency of either 30, 60, or 120 minutes for 14 days straight, preceded by seven days of their usual routine.

A daily email survey throughout the 21-day period assessed changes in fatigue, mood, and work performance of the participants.

"In this large-scale, pragmatic intervention, movement breaks demonstrated good implementation potential and effectiveness for improving psychosocial outcomes over the two-week intervention period. Hourly breaks offered the best balance between feasibility and effectiveness," the authors wrote.

"These findings support movement breaks as a potentially viable public health strategy to reduce the harms of prolonged sedentary behaviour," they said.

Implementation potential of the intervention was assessed using the 'Feasibility, Acceptability and Appropriateness of Intervention Measures' questionnaire.

Analysis of the survey results showed that all three break frequencies -- 30, 60 and 120 minutes -- were rated as feasible, acceptable, and appropriate, indicating an implementation potential.

Feasibility was found to be higher at lower break frequencies, while acceptability and appropriateness were high across all three.

Reported fatigue and low mood fell and reported good mood were seen to increase significantly across the three break frequencies, with improvements showing a dose-response pattern.

While the 120-minute break frequency showed the strongest implementation potential, it was the least effective, and although the 30-minute frequency produced the strongest improvements in fatigue and mood, it scored low on feasibility and compliance, the researchers said.

"The 60-minute arm offered the most favourable balance, yielding acceptability and appropriateness ratings comparable to the 120-minute arm, and exceeding MID (minimally important difference) thresholds for two of three psychosocial outcomes. In addition, it was the most commonly selected dose, selected by nearly half of all participants," they wrote.

Taking short breaks did not affect work performance, the survey results indicated.