Hourly movement breaks effectively counter harms of prolonged sitting

Hourly movement breaks of just 5 minutes each seem to offer the best balance between feasibility and effectiveness for mitigating the health harms of prolonged sitting, suggests a large study carried out under real world conditions and published online in the British Journal of Sports Medicine.

These brief interludes boost mood, lessen fatigue, and don't undermine work performance, the findings indicate, prompting the researchers to suggest this approach offers potential for a public health strategy and inclusion in physical activity guidelines.

On average, adults in high-income countries are sedentary for 11–12 hours during the day-a level of inactivity that has emerged as a significant public health concern, associated with heightened risks of many long term conditions and death, note the researchers.

Laboratory studies suggest that brief movement breaks are a promising option for offsetting the health harms of prolonged sitting, but it's not clear if they are feasible in the real world, or what the optimal frequency might be.

To find out, the researchers drew on 19,342 adults taking part in the interactive 'Body Electric Challenge' organised by National Public Radio (NPR) in the US. Participants spanned a wide range of ages, occupations, and work environments.

Nearly 60% (11,484) of participants took 5-minute walking breaks at their self-selected break frequency of either 30 (6108; 32%), 60 (9116; 47%), or 120 minutes (4118; just over 21%) for 14 days straight, preceded by 7 days of their usual routine.

Analysis of the survey results showed that all three break frequencies were rated as feasible, acceptable, and appropriate, scoring above 3, and indicating implementation potential.

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

The 30 and 60 minute break frequencies exceeded minimally important difference (MID) thresholds for fatigue and good mood, while only the 30 minute break frequency exceeded this threshold for low mood.

Hourly movement breaks offered the best balance between feasibility and effectiveness.

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

"While none of the tested movement break doses elicited improvements in perceived work performance or engagement that exceeded MID thresholds, all yielded small but favourable changes, on average (4%–7% for engagement; 1–3% for performance)," they add.

The researchers acknowledge several limitations to their findings: all outcomes were subjectively assessed, so prone to inaccuracy; participants were mostly White, female, and highly educated, so the findings may not be more widely applicable; and the study length was short, making it difficult to know how sustainable the approach would be over the long term.

Source:

BMJ Group

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