The strength of evidence for an association between gait speed and cognition was demonstrated by the number and consistency of results, as well as quality of the studies. Identification of diagnostic markers of motor cognitive risk has led to increasing interest in the effects of interventions for prevention of gait speed loss and cognitive decline in aging.

Texting while walking exerts a high cognitive load, and may be a sensitive test of the integrity of the cognitive–motor interface. We aimed to investigate the association between chronological age and gait speed while texting. A convenience sample of 308 community-dwellers was recruited: n ≥ 50 in each age group (20–29, 30–39, 40–49, 50–59) and n = 100 aged ≥60 years. Gait speed was measured over 10 metres under two experimental conditions: 1) walking at usual pace; 2) walking at usual pace while texting the message “Good morning Harry” on their smartphone. Both median gait speed with and without texting decreased with increasing age (p < 0.001). The differences between single- and dual-task gait speed were substantial for each age group and increased after the age of 50 years (p < 0.001). Median gait speeds while texting in people aged 50–59 (1.07 m/s) and ≥60 years (1.00 m/s) were below the recommended minimum for safely crossing roads (1.20 m/s). Texting while walking currently exposes people aged 50 and over to considerable environmental hazards. The significant slowing of gait speed while texting from middle age may be a marker of neurodegeneration, a cohort effect, or an appropriate compensatory response to reduce the risk of injury.