Choosing apps you can trust

How do you choose a trustworthy, evidence-based health app?

There is no sure sign that a health app works, so look for apps that are open about who made them, where their health information comes from and what they do with your data. Most apps for long-term conditions give little or no scientific evidence that they work, and most don't say whether health professionals helped build them². In apps for high blood pressure, the sources of health information were missing or low quality, which can lead people to enter or read their data wrongly³.

Checks worth making before you download:

• Who made it? The app store should name the creator. Don't trust an app if contact or website details for the creator aren't available¹.
• Where does its advice come from? Look for named sources and a note on whether health professionals were involved. Be cautious with words like "proven" or "clinically effective" unless the app points to the evidence behind its content.
• What does it do with your data? It isn't always easy to know what personal information an app will access or how it stores your data, so check your privacy settings and the app's data safety section¹. Features people rate as most important include clear consent, warnings about risks, and data that is protected and anonymised⁴. Chatbots may collect more data than you expect⁵.
• Is it easy to use? Intuitive navigation is also rated as very important⁴.

If you're unsure about an app, ask someone you trust to look at it with you.

Free or paid fitness apps: what's the difference?

Mostly the difference is which features, and which advert-free use, sit behind payment. Of 344 apps, 233 (67.7%) needed some in-app payment, usually to unlock a feature or remove adverts⁶. Around half (171 of 344, 49.7%) needed an ongoing purchase such as a membership or subscription, and 141 (40.9%) needed a one-off purchase⁶. Adverts appeared in 27.1% (93 of 344) of apps, mostly physical activity apps⁶.

Paid apps more often include techniques linked to more effective programmes⁷, and more expensive apps tend to be higher in usability and features, so free apps may have limited functionality⁸. Even so, paying doesn't clearly mean better results, and there is no good evidence that paying helps people keep going. A higher price isn't a sign that an app is safe, reliable or evidence-based, because most apps for long-term conditions gave little or no evidence that they work².

Dropping out is common whatever you pay: one report found a third of activity tracker users abandoned their device within the first 6 months⁹.

• Try a free version or option first, and see whether you use it before paying.
• Check whether the cost is one-off or ongoing before you pay.
• Expect adverts in some free apps; paying is often how they are removed.

What kinds of fitness apps are there?

Fitness apps fall into a few broad types: activity and step trackers, guided programmes and workout video libraries, apps with social or community features, and chatbot or conversational coaches.

• Trackers and walking apps record your activity and steps. One free national health service walking app also helps you set goals, gives tips, and counts brisk walking of even 1 minute as exercise¹⁰.
• Video libraries offer guided sessions. One national health service site has 23 instructor-led workout videos of 10 to 45 minutes¹¹.
• Social or community apps let you connect with other users and sometimes health professionals. These features may help people keep using the app².
• Chatbot coaches chat with you about your activity. They showed promise in randomised trials, but only 6 of 10 trials (60%) found the chatbot group did better than controls on activity measures¹³.

Goal setting, feedback and activity tracking are the features most often combined in programmes for older adults¹².

Decide what you want first: counting steps, following a guided plan, or doing workout videos. Look for an app that lets you set and change your own goals and see your progress. If you're new to activity, choose a simple option that starts gently and builds up, rather than a feature-heavy app.

Which apps suit specific needs, like running, yoga or strength?

The research doesn't show which app is best for running, yoga or strength. A few free beginner options exist, and they are described below.

• Running: look for a beginner programme that builds up week by week and lets you go at your own pace. One free national health service programme for absolute beginners can be completed in as little as 9 weeks, or taken longer¹⁰.
• Yoga or pilates: look for beginner-level, instructor-led videos and start with the shortest. One national health service video library includes postnatal yoga and pilates for back pain¹¹.
• Strength: the same health service offers a free strength and flexibility exercise plan for more exercise ideas¹¹.

These examples come from UK health services and may not be available where you live, but the same qualities are worth looking for in any app.

Choose an app that tells you to modify an exercise or see a health professional if something hurts¹³. Most studied programmes were designed for healthy, able-bodied adults, so they may not suit people with physical limitations or long-term conditions¹³. If you have a long-term condition, back pain or a physical limitation, ask your doctor, physio or other health professional what kind of programme suits you before choosing one.

How are AI and personalisation changing fitness apps?

AI and personalisation look promising, but the results so far are weak. Chatbot coaches have increased activity in some trials, but most of those trials were rated low quality (14 of 19), and over half had 75 or fewer participants⁵. Another review could not draw firm conclusions about whether chatbots work¹⁴, and only 6 of 10 randomised trials of conversational agents beat their controls¹³.

Personalisation itself seems more helpful. Apps with some personalisation tended to get better results than standardised apps¹⁵, and programmes that included text messaging or personalisation features were more effective⁹. AI-based personalisation is a proposed improvement, not one shown to work. It still has to deal with data privacy, the need for human oversight and over-reliance on technology¹⁵. Personalisation in AI coaching is seldom grounded in theory or expert input¹⁶. Benefits in obesity apps seemed to fade beyond about 6 months, and many apps lack the personal support needed to keep people going¹⁵.

There are also risks to know about:

• Wrong answers: conversational AI can give erroneous responses that may cause harm, and more flexible chatbots carry a higher risk of errors¹⁴.
• Safety checks: only 1 chatbot study described safety or data security checks¹⁴.
• Data: chatbots may collect more data than you expect, and vendors may not explain the risks clearly⁵.

Look for an app that lets you adjust your own goals, and check what a chatbot does with your data before you share personal or health details. Don't rely on a chatbot to decide what to do about symptoms or a health condition. Ask a doctor or other health professional.

Which combination of apps actually helps?

No particular mix of apps is known to work best, so start with one. Apps and activity trackers tend to add a modest number of steps: about 1850 more steps per day for adults without chronic illness⁹. In adults aged 60 and over with a health condition, activity trackers probably increase activity at about 12 months (by 1838 steps), though that finding mainly reflects wearable trackers rather than smartphone apps alone¹⁷. Other trials in older adults found short-term increases were possible, but no sustained benefit at 6, 12 or 24 months¹⁸. So whether the gains last is not clear yet.

More apps don't mean more activity. Some people download several apps and keep only one; 21.5% said they do this, and about 53% of health app users were reported to uninstall an app within 30 days⁸.

• Start with one app or tracker and give it a few weeks.
• Pick one that lets you set your own goals and see your progress.
• Add a second tool only if it fills a clear gap, such as videos for a type of exercise you like.

When to check with a health professional

If you're starting exercise after a long break, it's always a good idea to see your doctor first.

For an injury or a health condition, see a health professional, such as your doctor or a physio. An app can't replace advice from your doctor or another health professional, especially if you live with a long-term condition.

For a sore muscle or joint, ease off and see a doctor or other health professional if it persists or gets worse.

Call your local emergency number for chest pain or pressure (or pain spreading to the arm, neck, jaw or back, especially with sweating or feeling sick), severe breathlessness, fainting or collapse, signs of a stroke, a serious injury, or someone who isn't safe.