The benefits of getting more exercise cannot be exaggerated. Going for regular walks reduces the risk of heart attack or stroke by 31%. A study of 650,000 people found that being active for just 11 minutes a day after the age of 40 yielded 1.8 years of added life expectancy. Being active for an hour or more a day increased life expectancy by 4.2 years.
Exercise strengthens bones, boosts the immune system, lessens the risk of getting diabetes and a number of cancers (such as breast cancer), improves mood, and staves off senility. There is probably not a single organ in the body that does not benefit from exercise.
A healthy heart in our youth and middle age lowers the risk of developing dementia later in life, according to a study by Oxford University.
And it’s not just physical – a 30-minute walk can prevent a build-up of stress during the day, as aerobic activities help keep levels of the stress hormone cortisol in check.
10,000 steps a day is the standard recommended goal, although this has little scientific basis. What’s actually more important is how many minutes you are active in a day (experts recommend at least 150 minutes a week), and all the Fitbits measure this fitness metric, as well as steps. It’s especially important if your exercise is on a bike, where steps don’t really count.
The more sophisticated Active Zone Minutes measurement has now rolled out on all available new Fitbits, including the Sense, Versa 3, Charge 4, Inspire 2 and Luxe, but you’ll also find it on older Fitbits such as the Versa and Versa 2 as the FitbitOS updated them to the new metric, too.
Fitbits with the 24-hour heart-rate monitor (Inspire HR, Inspire 2, Luxe, Charge 4, Ionic, Versa Lite, Versa 2, Versa 3 and Sense) feature Heart Rate Zones, Cardio Fitness Level, and Guided Breathing Sessions.
They also show advanced Sleep Stages data, including duration of Light, Deep and REM sleep, plus give a Sleep Score. Those without the HR (Ace 3, Ace 2, Inspire 1) offer more basic sleep tracking.
Read our full feature to learn more about all the Fitbit scores and measurements.
Another big news story recently is that Google has bought Fitbit for a cool $2.1 billion. We don’t expect this to have much effect until later this year, and it certainly shouldn’t put you off buying a Fitbit now, as the buyout should fund further improvements in future models – but not for at least a year.
Fitbit features compared
For kids below the age of 13, the Ace 3 is a well-designed, basic starter tracker. It’s recommended for children aged 6 and up, and there are special Parent and Kid views, plus family challenges and virtual badges to be won. Its strap is smaller than even the Small size options with the other trackers, but we found the other Fitbits fit a child’s wrist just as well.
While it’s in Fitbit’s terms and conditions that children aged under 13 should use only the Ace, there are plenty of kids out there wearing “adult” models – parents just need to set up the child’s account using an older birth year.
The cheapest adult Fitbit wristband is the Inspire 2, but this lacks some features of the more expensive Fitbits, such as an altimeter – to measure floors climbed – and built-in GPS. But it is remarkably stuffed full of fitness functions for an entry-level device, not to mention it includes a heart-rate monitor, so can measure your Cardio Fitness scores and Active Zone minutes, as well as insightful Sleep Stages recording. It can also be worn as a clip rather than a wristband, although the clip accessory costs an extra £19.99/$19.95.
You can find even cheaper trackers if you consider older Fitbit devices – don’t worry, we’ve hunted down the Best Fitbit Deals for you.
If you do jog, run or exercise in any way, as well as walking you’ll be happy that all the latest Fitbits (except the Ace 3) include heart-rate-monitoring functionality.
Monitoring heart rate can also be used if weight loss is one of your key goals. The heart-rate function also gives you a much more detailed Sleep analysis – see further on for more details of this increasingly important health metric.
The Fitbit Sense and Versa 3 have built-in microphones and work with Amazon’s Alexa and Google Assistant voice controls – the older Versa 2 works with Alexa only.
The Sense and Versa 3 also boast a speaker and can receive phone calls when your iPhone or Android phone is close by. Phone calls on the wrist work surprisingly well.
If you’re looking for weight tracking, then check out our Fitbit Aria Air review. These scales sync with the trackers to add measurements of your weight.

Which Fitbit trackers have certain features?
All Fitbits have an accelerometer that measures motion patterns to determine your calories burned, distance travelled, and steps taken (although the Fitbit Ace 3 does not show calories burned, as Fitbit doesn’t want to add to a child’s possible weight anxiety issues.) All monitor sleep quality, but those with a heart-rate monitor give much more sleep detail.
Alarm
All Fitbits also contain a vibration motor, which allows them to vibrate when set alarms go off.
Floors climbed
The Charge 4, Versa 2, Versa 3, Sense and Ionic boast an altimeter that measures stairs (or height) climbed. The Ace 3, Luxe and Inspire 2 do not include an altimeter.
GPS
The Fitbit Sense, Versa 3 and Charge 4 are the only models in the lineup to have GPS built-in, without the need for a smartphone to be linked. Users can see distance, pace and elevation climbed, and review routes and split times. Like the Inspire 2 and Luxe, the older Inspire HR, Versa Lite and Versa 2 can connect to the GPS on your smartphone.
Heart-rate monitor
All current adult Fitbits monitor your heart rate on your wrist. They use Fitbit’s PurePulse technology that gives continuous, automatic, wrist-based heart rate, plus simplified heart-rate zones (Fat Burn, Cardio and Peak). The Versa 3 and Sense use the updated and more accurate PurePulse 2.0.
Additionally, these heart-rate-tracking Fitbits feature Cardio Fitness Level, which provides a snapshot of your cardiovascular fitness. Based on the estimated VO2 Max – calculated by your user profile, heart rate and exercise data – you can see how your fitness level relates to others of the same age and gender, and get guidance on how to improve over time.
Both the Sense and Versa 3 can notify you when your heart rate reaches high and low thresholds.
The Luxe, Charge 4, Versa 2, Versa 3, Sense and Ionic can also monitor the amount of oxygen in the blood (an important health indicator) with their SpO2 sensor.
Water Resistance and Swim Tracking
All Fitbits are water-resistant up to 50 metres. The Inspire HR, Luxe, Inspire 2, Charge 4, Versa 2, Versa 3 (not the Versa Lite edition) and Ionic will track your basic swimming metrics (laps, calories, etc) using distance to estimate strokes and laps. The new Fitbit Sense has a six-axis gyroscope to more accurately track strokes and laps while swimming.
Caller ID and text messages
All Fitbits show Caller ID when linked to a smartphone. All the wristbands except the Ace 3 also display text notifications and Calendar Events. When you get a WhatsApp or Messenger text, your Fitbit can let you know, and even include the message on its screen, saving you the bother of reaching for your phone. This might also help prevent phone theft on the street.
Phone calls on your wrist
With their built-in speaker and microphone, the Versa 3 and Sense can receive calls when your phone is nearby. You can answer the calls without getting your phone out, and the sound quality is surprisingly good.
Automatic sport recognition
The Inspire HR, Inspire 2, Luxe, Charge 4, Versa Lite, Versa 2, Versa 3, Sense and Ionic feature multi-sport exercise tracking. They know when you are cycling, running, hiking or playing sports including football, tennis and basketball. They will also recognise aerobic workouts such as Zumba, cardio-kickboxing and dance workouts, and log the workout in the Fitbit app along with an exercise summary.
SmartTrack automatically recognises and records workouts and captures all of the stats: how long you were active, calories burned and heart rate zones. By default, it recognises activities when you’ve been moving for more than 15 minutes. You can change this to anywhere from 10 to 90 minutes.
Reminder to Move
This is available on all the wristband Fitbit trackers. It encourages you to meet a mini-step goal of 250 steps each hour (approximately 2-3 minutes of walking). These prompts can be personalised to your schedule; for example, they can be put on “Do Not Disturb” during long meetings or appointments. And, of course, they won’t wake you at night.
It’s a great motivator to get up and move around, even if just for a stroll to get a glass of water or make a cup of tea. Studies have linked excessive sitting with being overweight and obese, type 2 diabetes, some types of cancer, and early death – bet that made you sit up…
Sleep tracking
All Fitbits check your sleep, too. They measure the time you spend asleep and check the quality of sleep – noting when you are restless or wake up during the night. Fitbit’s newer Sleep Stages measurements (on Inspire 2, Luxe, Charge 4, Versa Lite, Versa 2, Versa 3 and Sense) utilise heart-rate variability to estimate the amount of time you spend in Light, Deep and REM sleep, as well as time awake each night, to better understand your sleep quality. Sleep Score rates each night’s sleep from 0 to 100.
This is one of the great benefits of a tracker with a heart monitor, and sleep is now recognised as a major health metric. Six to eight hours a day is the recommended amount of sleep you should be aiming for. Improved sleep has immediate benefits to your memory, attention, cognitive function, and decision-making capacity, as well as helping to avoid type 2 diabetes and putting on weight. Sleep deprivation causes our appetite to go up and we feel less full, making weight gain more likely.
Sleep can make us happier, improve heart health, boost memory, even reduce the risk of dementia; it’s vital for restoring energy levels and boosting the immune system too.