Using App outside with speed/cadence sensors for power?

I’ve been using trainerroad exclusively inside with my Kickr core since starting. Now the weather is starting to get better (spring is almost here in SW Australia) I am wanting to do some sessions outside.
Recently just dropped a heap of cash on a new bike and don’t have the budget to upgrade my head unit.
Is it possible to use the app on my phone paired with a speed and cadence sensor to complete the workouts?

I believe you cant use virtual power outside as TR needs a support trainner to calculate the estimated power. To take your workouts outside a power is advised. There may be a few phone apps that maybe able to calculate power through GPS and speed.

  • Yes, you can pair compatible sensors to your phone and perform workouts outside in the native TR app. Many of us have done that in the past (and some may still do it today.
  • Correct, there is not “Virtual Power” applied when using the TR app outside.

You will need to perform the workouts using RPE (Rate of Perceived Exertion) instead.

Technically it could be done but there is no point as it would be wildly inaccurate.

Virtual power works inside because there are minimal variables. A particular speed generated on a particular make and model of trainer equals a certain wattage based on the trainer’s known resistance curve (or at least pretty close).

Outdoors, a host of variables come to play such as wind, air resistance of the rider and bike, slope of the road etc. which make any calculation of watts based off speed useless. Anyone with a power meter will tell you, it is not at all unusual for watts to be the same at 12 miles an hour or 30+ miles an hour depending on hills, wind and drafting; etc.