Using the Bluetooth Connection
With the cell phone app, you have the choice to maintain the Bluetooth 2 connection as always on (which will drain your battery faster) or to close it on exiting the app. I chose to close on exit to preserve my battery power throughout the day. Then when you want to see your activity, you open up the app on your cell phone, press the button on the LINK armband and it re-links with the app and updates your physical activity totals.
At times I had difficulty in getting the armband to link via Bluetooth. This was pretty frustrating and I was often going into my Settings on my iPhone 4s to reconnect the armband Bluetooth connection. This frustration is in comparison to the seamless experience I have with the Fitbit Zip and Striiv Play, which use Bluetooth 4.0.
BodyMedia FIT App Features
Calories Burned: This number is determined by BodyMedia's sensor algorithms. The sensor is an accelerometer that also senses skin temperature. This figure should be a pretty accurate assessment of the calories you burn, better than the guesstimate made by a pedometer.
Calories Consumed: Here, you have to do the work and use the Nutrition tab to input your food eaten. The app will sync with the MyFitnessPal.com app or web site if you prefer to use their tools, which include a barcode scanner. I used the app's food diary to enter my data and it works about as well as our free Calorie Count web site and app, although I prefer our site's diet analysis.
Calorie Balance: I appreciated this feature, as it was nice to see throughout the day whether I was burning more calories than I had yet eaten or whether I needed to get moving more to burn off what I had eaten. This is a nice simple way to see if you are on course to burn the extra 400 to 500 calories per day needed to lose a pound per week.
Moderate Activity: Health authorities recommend 30 to 60 minutes per day of moderate intensity physical activity. I set a minimum goal of 30 minutes per day. My walking workouts were tracked a moderate when I walked with friends at a pace of 20 minutes per mile.
Vigorous Activity: I was pleased to see that my brisk walk during my work breaks or when walking solo was usually counted as vigorous intensity activity.
Steps: The step count was pretty accurate, although it is being measured by the armband accelerometer.
Sleep: The sleep data is not transmitted via Bluetooth, so you will only see this figure if you have uploaded the data from the armband to a computer via the USB cable.
Workouts with the App
You need to have the Bluetooth connection linked with the armband during the workout. Throughout the workout, you can see your time, calories burned, steps, total activity and vigorous activity. Other than with the Quick Start, you will hear a bell ring once you reach your workout goal.
I liked the variety of workout tracking methods. These include:
Quick Start: this is a free-form workout, just start it and stop it.
Timed: Select from 20 minutes to 90 minutes or your own duration.
Steps: Set a step goal from 1000 steps to 6000 steps.
Calories: Want to be sure you burn off that bagel? Set a calorie goal for your workout.
Total Activity: This will include moderate and vigorous minutes.
Vigorous Activity: Select this to achieve your desired number of vigorous-intensity minutes during the workout.
You can view past workout summary data in the Workout History tab. You see only totals, you don't get a graph summary, speed, etc.
Bottom Line on the BodyMedia FIT LINK and App
If I were to select BodyMedia FIT as my main activity tracker, I would definitely prefer the LINK system to the CORE system (which doesn't have the Bluetooth connection.)
You still need a computer to get all of your data into the system and to see minute-by-minute details of your physical activity and a fuller analysis of your diet.
Personally, I don't like wearing the armband, especially as you are required to wear it 23 hours per day to get the full data collection power of the system and track your sleep quality. But I know people who love it and I can see why, as the quality of the tracking data is excellent.
I also experienced odd episodes when the armband didn't track my activity. I was very frustrated to find after an active day including a Zumba class that it tracked nothing. On another night it didn't track part of my sleep. This may be operator error, but it happened and it made me unhappy with the system. I also had difficulty getting it to link to the phone app with Bluetooth at times -- usually critical times when I really wanted to do a workout.
For these reasons, I personally prefer the Fitbit for its small size, being easy to wear, and its consistent data transmission via Bluetooth 4.0. The upcoming Fitbit ONE also tracks sleep and workouts. The original Fitbit does so but doesn't have Bluetooth.