The Withings Pulse 02 is a scant 8mm thick, weighs 8g and, minus the strap, is only slightly larger than an SD card. Despite its small size, it has the largest number of features among the fitness trackers in this round-up.
It not only tracks calories burned and steps taken, but elevation as well. It has a built-in heart-rate sensor and can measure a user's blood oxygen level.
On its front is a 128 x 32 pixel Oled touchscreen display. On one side is a button for you to toggle the display mode; on the opposite side, a micro-USB port for charging.
A single full charge is supposed to power the Pulse for about two weeks. But I found it lasted around 10 days.
A belt clip and wristband are bundled with the Pulse O2. The band has a black aluminium slot into which you slide the Pulse 02. It is secure and looks sleek too. But as the micro-USB port is exposed, the tracker is not even splashproof.
The Pulse O2 is designed to be set up through a mobile device via the Withings Health Mate app (Android and iOS). Set-up is a breeze. Hold down the button for three seconds to start the pairing. Launch the app and follow the on-screen instructions.
The display shows a wealth of information, including time, calories burned, elevation, steps taken and distance travelled. Press the button to toggle from one mode to another.
In terms of tracking performance, the Pulse O2 differs little from rivals such as the Jawbone Up24 and Nike+ FuelBand SE.
I especially like the fact that it can tell if I am running or walking. When I went for a 2.4km run, the device was able to detect the correct duration and distance. It also records automatically the height you have climbed, which is great for stair-climbing buffs.
However, for sleep monitoring, you need to activate it. Toggle to a display mode showing a crescent moon and a heart.
Swipe down on the crescent moon and activate sleep mode before you go to sleep, and deactivate it when you wake up.
Like the Jawbone Up24, the Pulse O2's sleep tracking is quite comprehensive, showing how deep or light your sleep is, as well as the number of times you wake up.
To check your heart rate, remove the tracker from the wristband. Swipe down on the heart and place your finger on the heart-rate sensor at the back of the tracker.
The readings were inconsistent. When I measured my heart rate, the first reading was 92 beats per minute (bpm) and failed to read the blood oxygen level. I waited two minutes before taking a second reading and, this time, it was 63bpm and blood oxygen level was 98 per cent.
The Withings Pulse O2 is a great value-for-money fitness tracker with its multitude of features. It is just a let-down that the heart-rate sensor's performance is erratic.
Material: Plastic with rubber coating
Water resistance: No
Connectivity: Bluetooth 4.0
Value for money: 3/5
Battery life: 4/5
This article was first published on July 30, 2014.
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