Among users, a pinch of competition - a social network of friends who sign up to share fitness scores - is all you need to make this an activity as addictive as Twitter ...
When Jon Mead, a devoted cyclist, visits a new city, he goes right to his smartphone app Strava to find the best bike routes. In Sacramento, California, where he works at a Fleet Feet running-gear shop, the 24-year-old uses MapmyRide to track his course in an archive.
Bethany Scribner, a runner who also works at the fitness gear retailer, likes the apps MapmyRun and Livestrong, which tracks nutrition in a daily pie chart showing fat, protein and carbs. MapMyRide, MapMyRun, Livestrong, Run4Good, MyFitnessPal - they're all part of an exploding arena of health and fitness applications for smartphones.
The trend, which falls under the umbrella of Health 2.0, an international tech movement grounded in San Francisco, is proving an obsession for programmers at code-a-thons, as well as users who get hooked on tracking their workouts, calorie intake and weight loss.
Among users, a pinch of competition - a social network of friends who sign up to share fitness scores - is all you need to make this an activity as addictive as Twitter is for some and Facebook is for others.
The Pew Research Centre, in a new report titled Mobile Health 2012, has found smartphone owners in the vanguard, with 52 per cent gathering health information on their palm-sized, micro-computers. That compares to 6 per cent of owners of regular mobile phones, the report says. In addition, Pew found, 19 per cent of smartphone owners have at least one health app on their devices - with exercise, diet, and calorie-counting programs the most popular.
Overall, the proportion of mobile phone owners who use their phones to access health data nearly doubled from 17 per cent two years ago to 31 per cent today, according to the report.
Ale Lauth is a senior health educator for Kaiser Permanente, America's largest managed healthcare organisation. She has witnessed the trend first-hand in her role as wellness guru for hundreds of Kaiser employees and doctors.
"We've definitely seen their usage increase," Lauth says. "The apps have come a long way, and they're constantly upgrading."
They are also proliferating. Click on Apple's health and fitness apps page and you'll find iRunner, Fitocracy, Fitter Fitness, Fitness Buddy, Fitbit, Fitness Pro, miCoach, Abs Workout, RunKeeper, Virtual Trainer - and about 250 more. In New Zealand, ACC's ActiveSmart, currently an online and customised training plan, will eventually have a smart phone app.
And it's not just fitness. There's a parallel world of apps geared to other aspects of health and wellness: iTriage, iFirstAidLite, InstantHeartRate, CuresA-Z, not to mention a host of downloadable apps such as OvulationCalendar that help women track their menstrual and fertility cycles. And, yes, there are apps with tips for carrying on when that fertility cycle is spot on.
The medical community is embracing the trend, holding contests to encourage programmers to design disease-specific apps that doctors can "prescribe" to patients with heart disease, diabetes and other chronic conditions.
This northern summer US Department of Health and Human Services Office of the National Coordinator of Health Information Technology held a contest for the best app to help consumers identify and reduce their risk of heart disease.
Our Ministry of Health and Health Promotion Agency are not in that space yet, but private insurer and provider Southern Cross' Primary Care and Health Society divisions are both exploring health related apps for launch in 2013.
The next phase is already in the works: apps that will transform your smartphone into a regulated medical device: think phones as electrocardiography, or ECG, machines that can detect abnormal heart rhythms and determine if a patient is having a heart attack.
Such clinical apps will not go forward without approval from the federal Food and Drug Administration. Already, US congressman Mike Honda is working on a bill to establish a new FDA Office of Mobile Health designed to regulate health apps.
Meanwhile, the private sector is leading the charge at Health 2.0-inspired code-a-thons, live events where developers gather to build apps and tools for improved health care.
A topic getting prime billing at the International Consumer Electronics Show in Las Vegas this January: The Human Body: The Next Digital Revolution.
For now, most doctors are happy to see patients using simple apps to motivate them to exercise, eat well and lose weight. MyFitnessPal has emerged as one of the more popular apps in this category, allowing users to set weight loss goals then diligently chart calories consumed, calories burned and poundage.
The swing of competition helps when they add friends to their wellness social network who can track each other's progress - or lack thereof.
"These are great motivators," says Lauth. "When you hit your goals, you and your friends see the results."