Ki Fit: The fitness gadget that has it all

What is it?

The Ki Fit is a nifty little device, worn on the arm, that monitors your activity throughout the day and night, collating information on how many calories you've burned, how much activity you've taken, and even how much you have slept.

How does it work?

The sensors in the armband measure different body responses. Your motion is tracked by an 'accelerometer', while the extent of your activity is measured by your 'galvanic skin response' - which in layman's terms means how much you sweat. Your skin temperature is also measured, along with 'heat flux' and the number of steps you take.

You can input what you've eaten into the food diary, allowing you to balance what you've consumed with what you've expended (or gain/lose weight if that's your goal). It measures your sleep duration and efficiency and shows your physical activity, and whether it was sedentary, moderate or vigorous. You can set goals for yourself and it will help you track whether or not you've reached them.

When you want to view this data, you simply plug the armband into your computer and the latest information is uploaded to the Ki Fit activity manager.

What's so good about it?

Quite simply, it's one of the most advanced fitness monitors on the market. It eliminates any need for a pedometer or heart-rate monitor, and goes far beyond the information they can offer you. Over the years I've used lots of different fitness devices - from various HRMs to GPS-based devices - but this one is different.

Where an HRM makes a guess at how many calories you've consumed during your workout based on a formula, the many sensors contained in the Ki Fit allow a more accurate reading. Also, a HRM tends only to be worn during exercise, and though you might run for half an hour, if you spend the rest of the day sitting down at a desk your overall calorie expenditure may be lower than you think. The Ki Fit therefore offers a far more holistic overview than any gadget I've ever tried.

How easy is it to use?

Very easy indeed. Once you have bought your armband and are signed up to the online monitoring service, the only thing you need to do is download a program that allows the activity manager to run on your computer. Downloading the data to the computer after this is extremely simple: you just plug in the USB and tell it to sync the device.

The only fiddly bit is that in order to accurately track your calorie consumption, you obviously need to input everything you eat into the food diary. There's no point lying - you are only cheating yourself! However, if you really can't be bothered and weight gain or loss is not your top priority, you can either skip this or just put in an estimate.

The activity monitor is clearly laid out and simple to use, while at the same time allowing more close examination of data. For example, you can click and drag the cursors around a particular time period and see exactly how many calories you burnt during it. The sleep monitor also shows when you were lying down, and when you were actually asleep, thereby assessing the efficiency of your time in bed.

Is it just a diet tool?

It is a powerful tool to aid weight loss or gain, but it's also fascinating for the fitness enthusiast. I wasn't trying to gain or lose weight, but I found the device addictive. I was particularly interested to learn how much effort or calorie burning really happens during classes such as boxing, or interval training, when you are doing short bursts of vigorous activity. The gadget not only shows how hard you are working during these activities, but how this impacts on your rate of calorie consumption through the rest of the day, and you can clearly see a higher rate after particularly strenuous exercise.

What are the downsides?

I did get several people asking me if the black armband meant I was in mourning, or whether it was monitoring my alcohol intake a la Lindsay Lohan. The sleep monitor can be rather depressing: it turns out that I get even less sleep than I thought I did. The gadget isn't waterproof (though it's splash-resistant), so it's no good for monitoring swimming workouts. Finally, it's not exactly cheap (see below).

How much does it cost?

A monthly subscription with the armband and a monitor will set you back £99. A yearly package is £268.55. Other subscription options can be found here.

Perfect if ...

You struggle with your weight. With such an accurate tool, you will be able to fully monitor your progress. We all know that if we eat more calories than we burn off, we'll gain weight. Now you can really see if this is what are you doing.

Best avoided if ...

You are a bit obsessive. I now have an addiction to this gadget that's going to be very hard to break. It's also best avoided if you prefer to live in blissful ignorance of quite how sedentary your life is.

• More information can be found at kifit.co.uk, or call 0207 307 8280.

Thanks to guardian.co.uk who have provided this article. View the original here.