Lose Watts going from Apple TV to MacBook Pro

Hi Guys,

Just changed from using an Apple TV to a MacBook Pro to operate zwift for cycling.

Other than this all the equipment is the same, I have ensured the trainer difficulty is set the same, however, I have lost watts by doing this?

Has anyone got any trouble shooting ideas why this may be the case?

I have swapped a few times between the systems to ensure it is not my imagination and I definitely can achieve higher watts using the Apple TV over the MacBook Pro.

Thanks everyone.

where’s the popcorn? This sounds interesting.


I’m inclined to believe it is your imagination :person_shrugging: However, I"ll hear you out. By what questionable method have you come to this conclusion? I switch between iPhone, AppleTV, and MacBook Pro all w/out any notion of “lost watts”.

Granted the method is not very technical. Initially whilst cruising it just felt more difficult to achieve a relatively easy wattage for me. Usually when warming up I do a quick acceleration of two pedal revolutions at about 80% power and this will generate somewhere in the mid 400 watts. Now when trying this on the MacBook Pro doing the exact same technique I can only achieve maybe 280 watts. I swapped back to the Apple TV and MacBook Pro a few times to see if this was my imagination and the same thing happened every time :man_shrugging:t2:

First time using the forum but think I have replied with a separate comment…

Are the power display settings set the same on both the AppleTV and MacBook Pro, i.e., 3s avg vs instant power? If not, that might explain what you’re seeing.

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I think so but will check this again tomorrow, thanks good suggestion :+1:

I hope so :sunglasses:

While you are at it can you tell us what is your power source…smart trainer or pedals/crank.

I use a wahoo kicker V 5

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Can you check within the in game options whether you’re using 3-second or 1-second power reporting?

Hi Colin, I will check later this afternoon, thanks for the suggestion :+1:

Hmmmm pretty frustrating. Checked the 3 second power Vs instant and the trainer difficulty and both the same settings.

Still same issue:

Apple TV - two revolutions with 80% hamstring pulls 450 plus watts

MacBook Pro - two revolutions with hamstring pulls 280 ish watts

Any troubleshooting suggestions v welcome :grin:

both connected via bluetooth?

Both via Bluetooth and via the companion app :man_shrugging:t2:

race mode enabled on both? (FYI this is a setting in the wahoo app, not Zwift)

I was going to suggest it might have to do with ANT+ versus Bluetooth - there’s some evidence to suggest one or the other can cause slightly different delays in gradient changes.

…but then you indicated you’re on Bluetooth for both. Hrm. Still wondering if there’s a latency difference.

One idea would be to ride the same route (something short like, say, Watopia Hilly Route) on both devices, maintaining the same W/kg, download the .FIT files and compare them.

I’m really voting for more of a presentation issue (with possible gradient/resistance lag).

The nuclear option: complete wipe of the ATV - factory reset it, update the OS, reinstall Zwift. Ensure your trainer is completely unpaired/removed from every device and app you have ever used. (including the Wahoo app, and any OS level pairing) Tabula rasa.

Hmmmm since setting up the Kicker V5 I haven’t touched the Wahoo app so I’m guessing it will be the same on both platforms :man_shrugging:t2:

Thanks CJ, some interesting suggestions. I will look into this over the next few days :+1:

There’s a clue: run it before doing anything else and look for firmware updates for the Kickr.


How about you pair via ANT+ to your head unit (e.g., Garmin, Wahoo, etc…) while paired via Bluetooth to Zwift. Then, using the displayed power on your head unit, go for a 5-10min ride. Finally compare the head unit and Zwift .fit file. Do this twice, once with the AppleTV and again w/the MacBook Pro.

Your constant is the head unit reading ANT+ from the trainer. In both cases, ideally the head unit .fit file should match the Bluetooth device (i.e., Apple TV and MacBook Pro) files. But if it’s as you say, at least one of them is not going to match up with the head unit.