![](http://69.16.207.172/~bonksadventure/wp-content/uploads/2018/02/4-athletes.jpg)
Apple Users
You can easily download the Calculator to your iPhone. Simply enter www.nobonkzone.com on your iPhone. You will see the icons on the bottom of the screen.
Tap the icon highlighted in red (above) and you will see the following:
Tap the “Add to Home Screen” button and the Portman Calculator will appear as an icon on your home screen to use before or during a workout or race.