5 Tips for Getting the Most out of a FitBit Flex

I have had my FitBit Flex for something like five months now, long enough to grow comfortable with its benefits and quirks and so I thought I’d put together a list of some tips that can help people who have one (or are thinking about getting one) get the most out of it.

1. Wear it and forget it

Perhaps the best thing about the FitBit Flex is that you wear it on your wrist. No need to clip it onto your clothing the way you had to with a FitBit Ultra, for instance. And since the FitBit Flex is waterproof, you can shower with it, meaning there is little need to take it off. This means you can wear it and forget it. You won’t find that you’ve left the house for the day only to leave your activity tracker on the dresser.

2. But set a recurring reminder to charge it

That said, I have found that I need to charge my FitBit Flex every 5-6 days. The battery has only run completely down once. The way I avoid the battery running completely down is by proactively reminding myself to charge the battery.

I use the reminder feature in Google Calendar and have created a recurring reminder to send a text message to my phone every 5 days, reminding me to charge my Flex.

When I get the reminder, I typically charge the Flex in the evening when I am doing my writing and getting the kids ready for bed. It doesn’t take more than 2 hours or so to get a full charge and by the time I go to bed, the device is once again fully charged.

3. Track specific activities

You can (with the latest firmware update) track individual activities with your Flex, which is useful if you want to know some detail about that activity. You do this by putting your Flex into Activity/Sleep mode (tapping it rapidly until you get the two flashing lights). When your activity is finished, you tap it rapidly again until you see 5 blinking lights.

What this does is sets a “start” and “end” marker. Your FitBit is constantly recording your activity and these markers allow you to look at a specific section of that activity to see the details. When you log into the FitBit dashboard, you will see those activities listed in the day on which you captured them. I’ve used this to capture the distance of my walk from my house to my office, for instance. Or how long a particular hike took. Here is what an activity record looks like for my lunchtime walk, as seen from the FitBit website dashboard:

Lunchtime Walk

4. Track your sleep after-the-fact (if you forget)

If you track your sleep, the Flex is great because there is no bulky wristband needed like with the older FitBit devices. All you have to do is remember to put the device into “sleep” mode the same way you put it into “activity” mode. You also have to remember to turn off sleep mode when you wake up in the morning.

But what if you forget? FitBit has you covered. Since it is always recording, the start and stop times only tell the system when your sleep started and stopped. It still records your “sleep” activity. So if you forget, you can go into the FitBit app, and add a sleep record for the previous night. Tell the app when you went to bed and when you woke up, and within a few seconds, you will see your night’s sleep, complete with how restless you were and how many times you woke up. Once you backfill the sleep and wakeup times, you will see something like this:

Sleep October

5. Invest in spare wristbands

The FitBit Flex comes with two wristbands, a large and a small. It is possible that my large wristband was defective but it only took about three months before it came apart. I switched to the small band, which, fortunately, fits on my wrist at its widest setting. But given that I had one wristband come apart, I invested in a 3-pack of additional wristbands just to be safe.

But do it sooner rather than later: when I ordered my 3-pack, the wristbands were back-ordered 8-10 weeks.

Anyone else using a FitBit Flex and have tips? Share them in the comments.


  1. Jamie,

    Thanks for this post. Some good tips and I think you sold me on the Flex.

    I currently have a FitBit One and after forgetting the past two days to clip it to my belt I’m one step closer to upgrading.

    If I’ve researched correctly the Flex does not calculate stories (stairs) like the One does. Is that correct?

    I hesitated going with the Flex because I thought I’d miss seeing the flights of steps info but if I forget to wear the device all together then it doesn’t really matter, does it?

    1. You are correct, the Flex does not count stairs. That wasn’t a deal-breaker for me. It was, in fact, the least useful piece of information that my Ultra collected and I don’t particularly miss it.

  2. I absolutely love my Fitbit Flex but I do miss the altimeter from the Ultra I had. I saw that you set an alarm to remind you about the battery getting low but I tend to get an email and an app alert when it does. Do you not get that same kind of alert?

  3. Fitbit is now sold in Japan by cell-phone providers, telling you the data can be automatically sent to your iPhone. Can you write a little about what you do with the data, where (if) you get it sent to and how?

  4. Jamie, you inspired me with your posts on Going Paperless and got me psyched regarding personal analytics. Been digging around and found http://www.tictrac.com which aggregates data from fitbit, Google Calendar, MyFitnessPal and many other with dashboard and exports. Still exploring, but sounded right up your alley.

  5. Thanks for the tips, I’m still a little list though, I just got mine today. Do I have to put it in activity mode to record steps and/or distance?

  6. My large band came apart also. I wore the small at its widest setting for couple months. It would come off playing sports and was generally restrictive. Finally my coworker suggested I email fitbit and they readily replaced the large band without any issues for free. Arrived in less than a week!

    In case you don’t want to invest 30 bucks.

  7. When charging my fitbit flex do I have to find a way to hold it tight in the charging station? Because unless I or something keeps it pushed in, it does not light up while charging

    1. Alex, I did not run into the problem you describe at first, but I have more recently. Usually rubbing clean the leads on both the charger and the FitBit device resolve the problem.

  8. I recently started wearing a fitbit flex, so I am not well versed in how it works. How can you tell what mode it is in? I was hanging some pictures and while hammering the nails in, it vibrated and two dots lit up making me think it went into sleep mode. I shook my wrist a lot and tapped it and more lights lit up. What happened? thanks!

    1. This happened to me when I was pushing a particularly dodgy trolley the other day. It translated the vibration as me tapping it :S
      If you tap it repeatedly for a second or two it will vibrate and change modes (sleep – activity or vice versa).
      On the FitBit site, there is an instruction manual that is much more in-depth than the little thing they give you in the packet. It’s a PDF, it tells you all about how the different modes work and how to do stuff with it.

  9. I just received a Fitbit Flex and Aria for Christmas… I absolutely love them! The ease with which I’m able to track my calories in/out is precisely what I needed. I still use a heart rate monitor for more precise calorie readings in the gym, but I’m able to record my workouts manually on my fitbit account and get a much clearer picture of my overall daily activity.

    Thanks for the forewarning regarding the bands. I’ll buy some new ones next month!

  10. Jamie do you know if you can swim with it as it says on the website it can be submerged up to 10 metres does anyone know if it can do that or not thanks shane nz

  11. I’ve had the flex for a week now and love it! In regards to tip 3, do you have to put it in “activity mode” to track or is that just of you want to see specific start and stop times? I have had it tell me in my dashboard that I have had a few very active minutes.

    1. Jenn, no, you only need to put it in activity mode if you want to see data between a specific start and end time. The device is always tracking. Activity mode just marks a specific subset of the recorded data and lets you see it on its down.

  12. I have a question about the ‘add activity’ section of the FitBit app. I find that even when I work out for an hour, my fit bit only shows me as “very active” for 11 or so minutes (not sure what a “very active” minute is…) but the step tracker does seem to show an appropriate increase in steps for my workout period. I want to give my self credit for my entire workout – not just what FitBit deems “very active” minutes (I would argue that my entire workout is very active!). I can’t seem to figure this out…so I started adding activities manually, but now I’m thinking it’s double counting…do you have any thoughts/recommendations on when you would/would not want to manually add an activity?

  13. I started doing the T25 workout videos. I don’t understand how to log it in my activities because it’s not a choice. Any help would be appreciated.


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