Fitdigits Default Maximum Heart Rate and Heart Rate Zones

Since we first started tracking heart rate on the iPhone back in 2010 (anyone remember the iPhone 2?), we’ve used the same default heart rate zones and calculations for maximum heart rates as our defaults – 220-Age was the maximum heart rate for anyone, and zones were cut up 10% per zone – period – the Haskell-Fox calculations.[1] As many of you have read, we’ve always encouraged people to set their own Max HR and Zones, as these defaults were developed in the 1970s on a small study of males around their 30s – it was never meant to be used as a standard. [2]

When I joined the company in 2011, I read Heart Rate Training by Benson and Declan, and have ever since been trying to get people to update to more modern zones. For a variety of reasons, including insistence from company founders and general public acceptance, it stayed Haskell-Fox, but that is changing.

We are still offering Haskell-Fox as an option, just no longer making it the default. 

It’s 2020, and Benson and Declan have updated their book to be the latest known to science and practice at this time. It is time for us as well to do what we can to make everyones experience, cardio development and results the best they can be right from the start.

While we still maintain that doing a personal assessment is the ultimate, our defaults will at least be the best they can be per current science. 

Default Maximum Heart Rate Calculation

The new maximum heart rate default is calculated based off the formula developed at Oakland University in 2007: [3]

  • HRmax = 192 − (0.007 × (age x age)).

The original linear equation had a confidence interval of ±5–8 bpm, while this nonlinear equation had a tighter range of ±2–5 bpm, and really helped take into account ages beyond above and below the main bell curve ages. 

You can always adjust and set your Max HR to the 220-Age or any other number (hopefully a measured one that matches you perfectly) – see how to set your maximum heart rate here.  

Default Heart Rate Zones Calculation

For heart rate zones, we are basing our zones and definitions per Benson and Declan’s newly updated Heart Rate Training manual, to help you maximize your training effectiveness based on your goals. [4]

Zone 1 Easy / Endurance 50-60% Aerobic
Zone 2 Endurance 60-75% Aerobic
Zone 3 Stamina 75-85% Aerobic (borderline Anaerobic)
Zone 4 Economy 85-95% Anaerobic
Zone 5 Speed >95% Anaerobic



[4] Heart Rate Training, Roy Benson & Declan Connolly, November 26, 2019, pp. 5


Working with Audio – v8 iOS

(View for Android)

Working with Audio – iCardio, iRunner, iBiker (iOS)

One of the biggest perks of exercising with your phone, besides tracking your workouts with a Fitdigits app, is using all of the awesome audio functionality that the mini-computer we now call smart phones have to offer. Be it jamming to your favorite iTunes playlist, exploring new music on Spotify, or being enthralled by an intriguing podcast, your phone offers you a myriad of options to entertain yourself while working out.

On top of that, Fitdigits apps have some unique audio functionality of its own. Voice feedback gives you a verbal summary of your workout thus far at pre-defined intervals, allowing you to adjust your workout as necessary to meet your goals.

I. Music, Podcasts & Other Audio

iOS 7 brought the introduction of the Control Center, a pull up menu from the bottom of the screen. The Control Center allows users to change songs, pause music, and more without leaving the app.


Another option to change songs, podcasts, audio books and more is to leave the app entirely. Fitdigits apps will work in the background as you browse through your other apps, and if you want updates of your workout, you can turn Notifications on. Go to Activity Options (gear icon on home screen) > Heart Rate Zones > Zone Alerts & Prompts > Zone Local Notifications. Also, you can turn on voice feedback or audio alerts, but more on that below.

Workout Voice Feedback

Fitdigits, using shrink ray technology perfected in “Honey I Shrunk the Kids”, has inserted a built in personal trainer right into your phone! Voice feedback gives your real time stats on your workout, based on pre-defined intervals. First things first, let’s turn voice feedback on.


Select your activity type you want to change settings on, then go to Activity Options (gear icon on home screen) > Voice Feedback. From here you can choose the sex of the voice and whether and what it will announce when you transition between Heart Rate Zones. Next are the Triggers. This is your chosen interval for when you will hear voice feedback. You can choose to have voice feedback come in when you you reach a certain amount of calories, elapsed time, and/or distance. For this example, I have chosen to have voice feedback triggered when I travel 1/4 of a mile.

The final option is what you want spoken when you reach the trigger. I have left all options turned on- I will get my current heart rate, calories burned, distance, time and pace. If you have music or other audio playing, when voice feedback occurs it will dim so you can hear the stats over your music or other audio.

If you cannot wait for the trigger, at any point during a workout, you can hear voice feedback by double tapping the middle of your screen when you viewing the dashboard.




In-Workout Settings

You also have the ability to make some small adjustments to voice feedback once you have started a workout. If you find yourself in a gym without headphones and want to turn voice feedback off, merely tap the gear icon in the lower right, and switch “Voice Feedback” to OFF. You will also see an “Audio” volume slider. This is the volume of the voice feedback, and will not change the volume of the rest of your phone. If you feel you are being yelled at, turn the volume down here. You may also want to check the volume settings in the iOS device (slide up from bottom of any screen) or iTunes music, as the level there can also affect the workout feedback volume.


Pairing your Heart Rate Monitor (HRM) with Fitdigits Apps

View for Apple Watch • View for Android

Fitdigits is compatible with Polar (H10, H7, OH1 and many others), Wahoo TICKR, Zephyr, Scosche Rhythm+ and Rhythm 24, and hundreds of other Bluetooth Low Energy (also known as BLE or Bluetooth 4.0) sensors.


  1. Put the Heart Rate Monitor (HRM) on per the manufacturers instructions. For chest straps, it helps if they are a little moist so the electrical signals can flow. Turn the HRM on if it has an on / off mode. 
  2. Make sure the HRM is NOT paired in the device’s Settings > Bluetooth*
  3. In your Fitdigits App, tap Menu > Settings > Sensors (alternative, tap the gear icon (Activity Options) on the main activity screen and tap Sensors). 
  4. Tap the Heart Monitor line item in Sensors. 
  5. If only one sensor available, tap OK on the confirmation. If there are multiple, find the one that is your brand / model, and having the strongest signal strength. 

That’s it! Tap the name of the paired HRM in that same screen to see details or delete the pairing. If you don’t have your HRM with you all the time, no need to delete the sensor, just turn it off in that screen. You can also turn it off easily in Gear (Activity Options), tap on the icon in the bottom row for the sensor type you want to turn on or off. 


While BLE compatibility is typically “industry standard”, Fitbit and some cheaper models like those produced by Xiaomi notably, claim they support BLE, but in reality it is a version they implemented where they didn’t go industry standards, but decided to keep their HR proprietary thus they did not build the ability for others to pair for Heart Rate.

If you haven’t already, download the Fitdigits app, and upgrade in-app to support the heart rate monitor functionality and more. All apps have the same functionality but different messaging and graphics in areas.


iCardio Apps iRunner Apps iBiker Apps iWalker Apps
Fitdigits iCardio app for Apple iOS Fitdigits iRunner app for Apple iOS Fitdigits iBiker app for Apple iOS Fitdigits iWalker app for Apple iOS
Fitdigits iCardio app for Android Fitdigits iRunner app for Android Fitdigits iBiker app for Android Fitdigits iWalker app for Android



Start a workout wearing your HRM and you are ready to finally realize your health and fitness destiny! When you are ready, read more on doing custom Fitness Assessments to get your custom heart rate zones, and why that is so important and effective in your own personal journey to health and fitness.


Try these initial steps if you are experiencing difficulties pairing, or these other articles for issues such as heart rate spikes or dropouts or general compatibility.

  • Chest Straps: Wet the electrodes on the belt part (which touches your skin) with water or saliva on the chest strap heart rate monitor to increase connectivity.
  • Optical HRMs: Make sure the green lights / receptors are pulsing in the part next to your skin.
  • Reset Bluetooth: Go to the Android Settings and turn off Bluetooth. Wait a few seconds then turn it back on.
  • Manually Close Your App: Exit the app and then double tap the iPhone home button. Look for the multitasking window to appear at the bottom of your screen. Tap and hold the Fitdigits icon to make a little red circle (minus sign) appear on all the apps. Then tap the little red circle for Fitdigits. Your app has now been manually closed. Relaunch the app and try pairing again.
  • Reboot: When in doubt, never hurts to reboot your phone/tablet.
If you still cannot pair with your Bluetooth HRM, check out the complete 


HRM pairing troubleshooting tips

Teams and Trainers (Beta)

Which team or group type is right for you – an inclusive, open Team page, or a Trainer portal? When you sign up to be a Star Trainer, you have your choice!

Team Group or Trainer Group?

Open Team Group

Open Teams are inclusive, and members have the ability to interact with each other within the group. A dedicated team page is the perfect place to view progress, send encouragement, and help each other on your paths to a healthy and fulfilling life.

This type of group is perfect for families, friends, training groups, corporate challenges and more.

Trainers’ Groups

A Trainer portal is specifically for Trainers, as the name suggests. A Trainer has contact and views of the individual trainees that sign up, but the trainees don’t have access to each others data. For example, Trainers can message trainees individually or as a group, but a trainee cannot. When allowed Auditing rights over users accounts, Star Trainers can view your trainees details, set their goals, and more.

Privacy Note: If you need a group for a study or requiring HIPAA security levels, where no data will be available or shared between members of the group, please create your group first then let us know at Only generic aggregate info will be available to group administrators.

Getting Started

  1. Creating a Team or a Training Group 
    The difference between an open Team and a Trainers’ portal. Which fits you the best? 

  2. Member Signu
    The how and where to add members to your group. 

  3. Member Roles, Privacy & Sharing 
    Everything you need to know to help you and your members customize each experience.

  4. All About the Team Pag
    Designing and modifying your open Team view for your members.

  5. Messaging and Communications 
    Individual and Team based notifications.

  6. Auditing Members 
    View and work with your Trainees / Team details.

Creating a Team or Training Group (Beta)

Once you’ve decided what type of group you want to create, and have become a Star Trainer, creating the group is easy.

Create team
  • Tap Menu > Teams.
  • Choose to Create either an open Team Group or more exclusive Trainer Group
Create a group or team
  • Add a Team name and information
  • Upload a group icon (square is best, max 2048px x 2048px)
  • Tap the green Create Group button
  • For Team Group, you will then be prompted to set your personal share permissions with the group, including whether to share your name, profile photo, and more.
  • For Trainer Groups, as the creator you become the master trainer of the group and have your default share permissions set to (insert set permissions or we need to prompt on Trainer Groups too).
Your Personal Group Share Permissions

Done! You now have your group setup and ready to go!

  • Note you can change the group information at any time using the Edit link on the top right of the Admin page.
  • This includes the ability to add an Invitation Code for the group, making it even easier to join your group – no more group name / password needed!

Next step

Member Signup 
The skinny on how members get added to your team.

Team Member Signup

Once you’ve got your team set, the next step is adding team members or trainees. Initially it will just be you in your group.

Initial Team / Group View

There are two ways users get added to your team. You can send them a stock invite email, or you can let them know in some other way the team name and password or Invitation code.

You can see, or edit, the team name and password or invitation code by tapping the Edit link on the top right of the team admin page.

To send out email invitations, click on Invite on the group admin page, and enter the emails you want to send the invite to separated by commas.

Send invite emails

Both methods will inform your invitees that

  • Members need to have a valid Fitdigits account to join. They can create an account at or in any of our apps like iCardio.
  • They will need to be logged in, then tap/click Menu > Teams / Groups, and then Join Group. There they should enter the invitation code or team name and password they were supplied.
Edit Team info / add Invitation Code

They will then be prompted to choose Sharing Preferences.

See here for more on Member Roles, Privacy & Sharing. Once they’ve set their preferences, they will be redirected to the main Team page.

Member Roles, Privacy & Sharing 
Everything you need to know to help you and your members customize each experience.

All About the Team Page 
Designing and modifying your open Team view for your members.

Messaging and Communications 
Individual and Team based notifications.

Auditing Members 
View and work with your Trainees / Team details.

Auditing Team Members

View and work with your Trainees / Team details.

Requirements to Audit a member:

  1. User must have given permission for Coaches View
  2. Auditor must have Auditing / Coaching permissions

From the user, they would either grant the permission when signing up, or they can modify it in Group Menu > Group Permission Settings

Once permissions have been set, you can access Coach Viewing / Auditing of another persons account through the Coach Whistle icon next to the user to audit:

This will give you a full view of what is going on in their account, though it excludes viewing or accessing their personal inbox.

Back to Team Overview

Team Messaging and Communications

There are a variety of settings and methods for Individual and Team based notifications and messaging.

Group Admin View:

From here you can send Group Invites, or even a push message to your entire team or a specific user, which will create an Inbox item for them in addition to the notification.

You can also message users directly to their inbox, which does not send a push message. Tap on the envelope in the listing in the admin page.

Of course, you can also visit any shared workout and leave comments in the comments section:

Next: Auditing Members
View and work with your Trainees / Team details.

Managing The Team Page

Designing and modifying your open Team view for your members.

Add a custom leaderboard, group workout feed, roster, custom blog section and more to your groups page. Personalized widgets, additional messaging, graphics and more help complete the experience for you and your team.

Once your team is created, a default groups page exists for your group. The default widgets include your member roster, a personal workout feed, and a feed for the Fitdigits blog, however contents are easily customizable.


You must be a Group Owner or Group Administrator to modify the group page for all users (see Managing Users).

From the Group detail page, tap the Menu icon in the top left. Administrators and Owners will see the Preview checkbox in the upper right. When checked, you are viewing the group page as it will show to other members (depending on widget choices).

1. Uncheck Preview to go into Edit mode.

Click the Menu (three line icon) in the upper left to view the menu. Turn off Preview mode to edit your page.


When in edit mode, each widget on the page has a blue administration bar above it.

Tap the X to remove the widget from the page view.

Tap the pencil to edit the viewing properties of the widget (whether it is shown to admins only or all team members) as well as the detail and options for the widget.

You may also click and hold the top blue administration bar and drag-drop the widget into different areas or sections of the page, so you can change the layout and display to fit your tastes.



This will create a sortable leaderboard featuring a variety of stats you can choose from, including time, distance, calories and more.

Group Workout Feed

See the workouts completed by team members who have opted-in to share their workouts to the group. Tap on the icon to go to the details.

Group Roster

The Roster is added by default. This will list all of the members of your group, along with information they have given permission for members to view.

Personal Workout Feed

If you want to just see your own personal workout feed. This does not show on other group members pages.


Add a custom banner image with this widget.


The HTML widget is one of our most flexible. Basic HTML can be used to create messages and presentations to your group with almost endless variety.


Show a calendar with checks on all the days the group recorded activity, see the totals below, and select a day to drill into specific activities.

Blog Feed

You can easily link to an existing blog feed. You will need to know the blog feed URL and specify how many posts you want to show.


Choose from a variety of different page layouts to change the look and feel of your groups page.


This will reset your page to the default widgets and settings.

Next: Messaging and Communications 
Individual and Team based notifications.

Team Member Roles, Privacy & Sharing

There are 4 types of Member Roles. Team Owner, Team Admins, Team Auditors and Team Members.

Each team is structured to have one group Owner and one (or more) administrators (admin). The base team is good for up to 10 total members. The Owner of the team has permission to add and delete users as well as assign group roles.

Admins are set by the Owner or other Admins. They also have full views, member add, delete and role administration rights. An Admin cannot make anyone an Owner as there is only one Owner per group.

An Auditor must also be an Owner or Admin. As an Auditor you are able to view in detail and work within team member or trainees accounts and information. See Auditing for more on how that can work for your programs!

Member Privacy & Sharing Permissions

Each member has the ability to specify what they want to share with a group. This will affect the view of things like group feed, roster, leaderboard stats and more. Members can view or change their settings at any time from the group view, tapping the menu icon and My Group Sharing Permissions in the main menu.

Next: All About the Team Page 
Designing and modifying your open Team view for your members.