I tried the Apple Watch's best new fitness feature in ages, but it's not for everyone

TrainingPeaks API screenshot
(Image credit: Future)

Apple has partnered with fitness coaching app TrainingPeaks to deliver a new custom workout integration to the best Apple Watch models, which enables you to load scheduled workouts from the TrainingPeaks app directly onto your Watch. The twist? It’s all done through the Apple Watch’s Workout app, so you don’t have to have a separate app on your watch to use it.

For those not in the know, TrainingPeaks is one of the best fitness apps for serious athletes. It’s great for runners, cyclists, and triathletes, allowing you to create your own workouts (or, if you’re training with a coach, have your coach do it for you) and schedule them into a calendar. Every day, you can open TrainingPeaks and see what kind of training you have scheduled for that day.

TrainingPeaks API screenshot

(Image credit: Future)

Once you’ve completed a workout, you’ll see all your stats as usual synced from your smartwatch, but if you’re training with a coach, they can also see your stats. You’ll be able to message them on the app and let them know how you got on.

Now, for Apple Watch users, the new application programming interface (or API) from TrainingPeaks means you can open the Workout app on your watch and see that day’s workout ready to go. For example, while testing it in beta, Apple hooked me up with incredible ultramarathon coach Jason Koop, who had designed an interval workout for me.

After a brief warmup, I was to go hard for 400 meters, before taking it easy for 400 meters, then for 600 meters, and so on – a “pyramid set” where I ran further and faster, before bringing the distance back down. This all appeared straight away as soon as I opened my Workout app, with purple highlights to indicate it was a custom workout.

TrainingPeaks API screenshot

(Image credit: Future)

The interval workout interface was a pleasure to use on the Apple Watch Ultra 2 unit I was using. Once I hit start, I began the first set – a slow warm-up run for two kilometers – and went too fast right out of the gate. Immediately I got an “Ahead of Range” notification prompting me to slow back down to my target pace for the duration of the warmup. Virtual pacers are nothing new, but to have Koop set the speed and beam it to my watch automatically, rather than fiddle about on the watch’s settings, made life much easier. 

The rest of the workout passed without incident. I didn’t have to change segments with the Action button, because it was done automatically: my Apple Watch calculated the distance I was traveling and automatically told me when to speed up for my next “work” set or slow down to recovery pace. Once I was all done, I could save it as a Custom Workout to try it again, while TrainingPeaks would recommend the next one tomorrow. 

The whole experience was sublimely simple. I ended the workout early – which is what happens when you try to squeeze exercise and testing sessions between meetings – but once it was over, Koop messaged me in the app to ask how I got on. 

TrainingPeaks API screenshot

(Image credit: Future)

TrainingPeak’s new API integration is going to be a game-changer for serious athletes, whether you’re creating training plans for yourself or you’re having a coach do it for you. Especially if you have a coach do it for you: the idea of someone else beaming recommended workouts to your wrist, using the Apple Watch’s excellent Workout app to do so, is an appealing one.

It certainly takes the Apple Watch Ultra series a significant step closer to toppling the titans of the specialist endurance watch game: your Garmins, your Wahoos, your Polars. 

However, what does this mean for your average person looking to use the Apple Watch to run their first 5K? Unfortunately, very little. The ability to schedule workouts in advance only comes with TrainingPeaks Premium, which costs $124.99 (approximately £100 / AU$185) per year, and those dipping their toes into running, cycling or swimming for the first time are unlikely to be paying that much for an app.

However, new starters can get cracking if they choose to do so with individual plans you can buy for as little as $4.95 (around £4 / AU$8), and a TrainingPeaks representative clarified to me that "any structured run or bike workouts within these plans can be synced to the Apple Watch Workout app to follow on your wrist". 

TrainingPeaks is already a fantastic tool, and the success of TrainingPeaks’ API integration shows that there’s a bright future for third-party apps and watchOS 10, especially from a fitness perspective. It’s just so easy to use, and it makes me excited for what else is in the pipeline for 2024. However, new starters are probably better off with one of the best Couch to 5K apps. 

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14/12/2023: This article has been amended to mention training plans that can be individually purchased, not just as part of TrainingPeaks' premium subscription. 

Matt Evans
Fitness, Wellness, and Wearables Editor

Matt is TechRadar's expert on all things fitness, wellness and wearable tech. A former staffer at Men's Health, he holds a Master's Degree in journalism from Cardiff and has written for brands like Runner's World, Women's Health, Men's Fitness, LiveScience and Fit&Well on everything fitness tech, exercise, nutrition and mental wellbeing.


Matt's a keen runner, ex-kickboxer, not averse to the odd yoga flow, and insists everyone should stretch every morning. When he’s not training or writing about health and fitness, he can be found reading doorstop-thick fantasy books with lots of fictional maps in them.