In the world of training with power, it seems FTP is king. Sure, it’s certainly not the be all and end all of power metrics, but it’s one that almost all people who train to power (or just ride around with power) seem to care about. Trouble is, FTP tests suck. Like properly suck. The main old school method is to warm up then go all out for 20 minutes of evenly paced but eye watering max effort. You then take 95% of your average 20-minute power to calculate your FTP. Doing this on the trainer is tough enough. On the open road outside of a race breakaway or time trial it’s almost impossible.

That’s where the Garmin IQ app “What’s My FTP” by Xert comes in. The app claims to automatically actuate your FTP based on monitoring your power during a ride. In other words, give you your FTP without having to do an FTP test! Once you download the app from Garmin IQ and install it by syncing your device, you can then select it as one of your data fields. Nice and simple. I recently gave the app a test over three of my rides.

Before we go on, for reference my FTP usually hovers around the 205-215 watt mark (3.2-3.4w/kg) depending on my fitness/freshness cycle.

Ride 1: Outdoor Sweet Spot

For my first ride using the app I headed outside along some local roads for two hours. I didn’t go out to test my FTP or push super hard, more like a solid two hours at sweet spot with a couple of efforts thrown in.

This bike bike has a PowerTap G3 hub laced into the Planet X rim.

Over the course of the first hour, the FTP number slowly crept up from the initial 100 watt starting point gradually settling at 205 watts. It didn’t change during the second hour (the number doesn’t go down during a ride, only up). Judging by how that ride felt (solid but not exhausting) the app prediction seems about right.

Ride 2: Indoor Trainer with Zwift

Next I set my Garmin up to run alongside Zwift. I had planned out an easy spin for half an hour, followed by a dig up the virtual volcano climb, then finish off with some easy spinning. During the warm-up the number slowly crept up as per normal, sitting at 170 watts as I approached the base of the climb. I ramped up the power and held it as steady as I could. Eight minutes and 31 seconds later I crested the virtual top – averaging 235 watts. The Xert app was showing a calculated FTP of 210 watts.

The dial around the outside changes from green to red as you push harder.

Just outside the top three on Zwift’s real-time Volcano leader board.

Another common way to test your FTP is the 8-minute test. It’s the same as the 20-minute test just, errrr, a bit shorter. You then take 90% of that figure. Taking my rough eight minute 235 watt figure, 90% of that gives 211 watts. A single watt difference. Off the back of that maths, once again the app is looking fairly accurate!

Ride 3: Outdoor Segment Attack

My final test ride was a short hard effort around my local training loop. I tried to keep the wattage high (for me) and threw in one Strava segment attack for good measure!

As per usual the FTP figure rose steadily from the start, then my single sub 2-minute segment smash bumped the calculation up to 221 watts. I was a little surprised to see it that high. Yes I pushed hard for that two minutes, hard enough for second on the Strava leaderboard, but not race effort sprint hard. That’s the highest FTP reading I’ve had and I dare say a little optimistic. I was feeling fit yes, but certainly not fresh. That said, I’ve been riding hard of late so maybe I’m just getting stronger and don’t know it! ;-)

Holding it “steadily hard” with one cheeky segment attack!

Final Thoughts

If you’re like any fairly sane person out there you probably cringe at the thought of doing a 20-minute FTP test. It’s the worst kind of torture. The. Worst. The What’s My FTP app makes it simple to figure out your FTP from just regular (hard) riding. It’d be interesting to see the number after a tough race or time trial. Accuracy seems good and the coloured dial around the outside of the number gives you a good indication of whether you are currently increasing your FTP calculation. You could of course just pour through the numbers after your ride and figure it out with a bit of simple maths, but this app takes all the effort out of that.

New FTP setting for me (3.5w/kg).

The only downside I can think of is that I don’t think you can access the app’s data once you’ve saved your ride. It resets itself every ride (or lap). Be sure to note the number before that point. Overall though, it’s a great little tool to have tucked away on one of your Garmin screens for when you fancy some testing!