Am I normal? Does ten thousand steps represent a balanced day?

Background: Previous research highlights the 24-hour activity cycle as a key framework for exploring how physical activity, sedentary behaviour, and sleep interact to affect health. This approach emphasizes the need to examine all daily activities for promoting health and preventing illness. Challenges in accurately capturing this remain, especially concerning posture allocation and how this is influenced by activity levels.

Purpose: This study explored the relationship between time spent in primary postures and step count-defined activity level in a working-age population.

Methods: We selected all individuals from the BCS70 study with 7 days of valid data (3,457). Days were categorised into three activity levels, inactive (10k steps/day). Daily time in the different primary postures of lying, sedentary and upright were calculated. Mean daily time in each posture was summarised by activity level. ANOVA with Tukey post-hoc testing was used to identify significant differences in posture allocation across activity levels.

Results: From 24,829 days of posture data, increased daily activity levels were associated with significant decreases in sitting (F(2,24826)=2658, p<0.05) and lying time (F(2,24826)=203, p<0.05) and a significant increase in upright time (F(2,24826)=6123, p<0.05). For days when the activity level exceeded 10,000 steps (8,784 days), participants exhibited a balance of time spent lying(8.23h), sitting(7.76h) and upright(8.01h).

Conclusions: We observed a reduction in sitting time and increased time in an upright posture with increasing daily step count. In this population of ~3500 individuals aged 46, for days where stepping was over 10,000 steps, we found a balanced distribution of daily time across lying, sitting, and upright postures, giving an 8:8:8 hour ratio in the 24-hour period.

Practical implications: We have demonstrated a relationship between sedentary behaviour and activity level. This relationship will be important for researchers interested in “sit less and move more” interventions.