ANI, Washington (US): Smartphone fitness apps and wearable activity trackers do, in fact, help boost physical activity levels, finds a review and pooled data analysis of past studies. The review published online in the British Journal of Sports Medicine found that the effect is small to moderate. However, it may be worth prescribing them to motivated patients, given the importance for the health of increasing daily physical activity by any amount, say the researchers. Globally, physical inactivity represents a leading cause of death worldwide and is thought to cost billions of dollars every year, the researchers noted. The apps and tracker programmes that also included text-messaging involving prompts and cues, and tailored features, were more effective. And certain components, such as goal setting, planning, and tasks graded by degree of difficulty, were significantly associated with greater levels of effectiveness. The researchers acknowledge that given the relatively small number of women involved, the results may not be widely applicable to both sexes. Nevertheless, "Interventions using smartphone apps or activity trackers seem promising from a clinical and public health perspective, promoting a significant step count increase of 1850 steps/day," they write. "These results are of public health importance according to recent evidence showing that any physical activity, regardless of intensity, is associated with lower mortality risk in a dose-response manner and that an increase of 1700 steps/day is significantly associated with lower mortality rates."