Smart watches and other wearable activity trackers (WATs) encourage wearers to walk for up to 40 minutes more a day according to a recent review by University of South Australia researchers in The Lancet Digital Health.

Lead author Ty Ferguson, PhD candidate and clinical placement supervisor in physiotherapy, says that the umbrella review brings together data from almost 400 studies involving 164,000 people using WATs to monitor their physical activity.

 The review looks at the effectiveness of wearing activity trackers, including how they increase people’s physical activity levels and whether they affect other health outcomes such as heart rate, blood pressure and body composition.

The major finding from the analysis, shown across all of the studies, is that WATs encouraged users to walk for about 40 minutes more each day, equivalent to about 1800 more steps, and also resulted in incidental weight loss of one kilogram over five months.

‘That probably doesn’t sound like a lot in five months, but these weren’t weight loss studies; these were physical activity studies,’ says Ty.

When the team looked at physiological and psychosocial outcomes, the findings were less strong but still favourable. 

Blood pressure, cholesterol and glycosylated haemoglobin improved in people with type 2 diabetes and other health conditions, along with quality of life.

‘The take-home message is that WATs are helpful. They may not be helpful for everyone, but we found that across the board, wearing one of these devices is likely to give you a chance to improve your physical activity,’ Ty says.

Physical activity guidelines recommend 150–300 minutes of moderate to vigorous physical activity weekly and Ty says that using a WAT can help with setting daily and weekly targets as well as providing prompts.

‘If you start measuring your activity and you realise you’re below the recommended guidelines, you have a target that you can improve on. A WAT can also give you that external prompt, saying, “Actually, you’re maybe not as active as you thought you were.” 

'It doesn’t cheat in that regard, whereas you might tell yourself, “I’m okay; I won’t go for that walk today.” 

'The nudge on your wrist is really beneficial,’ he says.

Ty says that physiotherapists can encourage their clients and patients to use WATs to help them to increase their physical activity.

‘The more you move, the more likely you are to reduce your symptoms of pain and lack of mobility. 

'If you have people coming to your clinic who have chronic illness and you find out that they are quite inactive, this could be an option for them. 

'They may already have a device, but they may not be using it—they may be using it as a watch rather than as a tracker,’ he says. 

‘It’s an avenue for us as physios to say, “Maybe just keep an eye on it. 

'Work out what you’re actually doing and then come back to me next week and we’ll see how you’re going.”’

WATs are also useful in physical activity research, says Ty, who is completing his PhD with Professor Carol Maher at the Alliance for Research in Exercise, Nutrition and Activity at the University of South Australia. 

He has used them in his own PhD research program, examining patterns of sleep, activity and sedentary behaviour, and says that the devices and associated apps can collect a wide range of information and even graph activity over time.

‘They’re an objective measure of physical activity,’ Ty says. 

‘It costs a little bit more than doing an interview, where someone self-reports, but they give you such rich data. 

'If we’re doing intervention studies, it’s a good resource to look at, especially knowing that they actually help people.’

‘Effectiveness of wearable activity trackers to increase physical activity and improve health: a systematic review of systematic reviews and meta-analyses’ can be accessed here.