31 per cent of Americans currently use quantified self tools to track their health and fitness, from smart watches and wearable fitness trackers to smartphone apps, a new report has revealed.

The survey by AI ad firm Rocket Fuel also revealed that 43 per cent of users are willing to share their behavioural data for more personalised digital ads, and they were five times more likely to purchase due to digital ads than non-quantified self users.

29 per cent of consumers currently use a website or app not associated with a wearable device to track their personal data, while 16 per cent use a wearable fitness or health tracker. Fitbit, Nike+ Fuelband and Samsung Gear are the most popular wearbles, while MyFitness Pal, WebMD and Map My Fitness topped the list of websites and apps.

The surge in life logging appears to be having positive results for consumers, with 90 per cent of those who do so saying it has motivated healthier lifestyle choices, with users twice as likely to exercise more and be in better shape than they were a year ago than non-users. Over a quarter have changed their diet habits as a result of health tracking.

“The health and fitness advantages of the Quantified Self movement are clear, as is the abundant marketing opportunity to target a growing population of health-conscious shoppers who are highly receptive to digital media and comfortable sharing behavioural data to receive more relevant ads,” said Christian Janelli, director of category strategy for consumer packaged goods at Rocket Fuel.