Heart rate monitor/ racing

Hi .
i am using a garmin heart rate monitor but i cant get it to pair with zwift companion or ipad.
do i need to get a small ant +dongle for the i pad and use that in stead of bluetooth.
I want to get it working so i can do the races.
which brings mt to my next question. Is it right in saying that you divide your FTP by your weight.
226 % 68 =3.32 . that puts my in cat B
I did a race in cat C and got smashed and nearly died after so i can only assume i would be way off cat B and out of curiosity what has your weight got to do with anything on a indoor bike ?

You will need either CABLE or Viiiiva HRM to bridge the ANT+ signal to the iOS device. Or you can get a duel band HRM like Wahoo Tickr

Zwift on mobile devices is Bluetooth only.

@Gerrie_Delport can answer the second question.

1 Like

Hi @garjd1981

Paul is correct the Garmin HR strap is most probably ANT+ only.

Yes you do have the formula correct FTP/weight (kg) = w/kg.

So yes you are a B cat.

Races is hard, they start of very very fast. And there are some people that enter the incorrect pen and that make it unfairly hard, but that is a different point.

I would suggest linking your account to Zwiftpower.com (ZP), ZP will track your race performance and suggest the correct category.




FTP in races is different.
Why? Simply because you aren’t able to push power constantly on a target value into your pedals. You have to move with the field often times counter attacking. Many people have a small lactat (anaerob) threshold and/or are unable to regenerate fast enough.

1 Like

so if I am ment to be in Cat B but coming last in cat C do i have something wrong or just not fast enough.

It may be a learning curve to get used to racing, or your FTP is a bit high.

Are you currently on Zwift power? if yes what does your profile show your Category?

ZP take the average of you best 3 races in the last 90 days.

So if you race in C and you does not exceed the category limits you wont get DQ. But once you exceed them your required category will move to B.

Thanks for your reply. i did the 20min FTP test . Do i need to do a longer test for a more accurate FTP for races and training programs.
sorry im new to zwift and still iorning out the cracks


No you don’t have to do a longer test.

Go do a few C cat races and see where ZP put you. If you did not win a C race then I would think you can do a few in C without causing to much trouble. LOL

1 Like

Do I need to sign up to ZP or does zwift automatically do it once your racing

No you have to sign up.


perfect thanks , and do i need to do this before every race .

No, It’s one time thing to do.

Hey Paul,

I’m using a Garmin Bluetooth heart rate monitor and zwift still doesn’t seem to find it when searching.

Batteries have been changed in HRM recently, uninstalled and reinstalled Zwift and all the other basic troubleshooting you would expect.

Strange thing is that the app on my phone does recognize the HRM but when I use the app on Mac it doesn’t recognize the HRM.

Have you seen anything like this abd can you offer any advice?

Kind regards


Hi Adam,
I don’t know if this will help but bluetooth is a one device only connection, unlike Ant+ which will link with multiple devices.
So try to ensure that all other devices are switched off or their bluetooth options are turned off so that the HRM can connect with the device you want.
Hope that helps.

1 Like

The Polar series of Heart Rate Sensors are interesting, especially the OH1.
It is able to connect to a bluetooth device, multiple ANT+ devices and record
the workout session internally, to upload to Polar flow, all at the same time.
I find it very accurate. It always gets a good review.