Apple killed Project Mulberry in February. Six weeks later, they shipped an AI fitness coach anyway.

Workout Buddy landed with watchOS 26 and it’s not the vaporware health coaching platform Mulberry was supposed to be. It’s smaller in scope and strapped to your wrist. Powered by Apple Intelligence, it analyzes your workout data, heart rate, pace, and Activity ring history to deliver personalized spoken motivation mid-session. No separate app. No subscription. Just your Apple Watch telling you to push harder when it knows you can.

I’ve been running the developer beta for four weeks across strength sessions, runs, and cycling. Here’s what actually works, what doesn’t, and whether this changes the AI coaching game that apps like Fitbod and URUNN have been winning.

Quick Verdict

Aspect	Rating
Coaching Quality	★★★★☆
Workout App Redesign	★★★★★
Personalization	★★★☆☆
Beginner-Friendly	★★★★★
Value for Price	★★★★★

Best for: Apple Watch owners who want mid-workout feedback without paying for a coaching subscription Skip if: You need structured programming or periodized training plans Price: Free with watchOS 26 on Apple Watch Series 7 or later (Workout Buddy requires Series 10+ or Ultra 2+)

What Workout Buddy Actually Does

Strip away the WWDC keynote polish and Workout Buddy does one core thing: it talks to you during workouts based on your real-time biometrics and training history.

Start a run. Two minutes in, your watch says “Your pace is 15 seconds faster than your Tuesday average. Hold this effort.” Hit a strength session and it might say “Heart rate recovery between sets is improving this week. You’re adapting well.”

The coaching comes through the Apple Watch speaker or connected AirPods. It’s context-aware in a way that generic “Keep going!” prompts aren’t. Workout Buddy pulls from your heart rate data, recent workout history, Activity ring completion rate, and current session metrics to generate its feedback.

The Apple Intelligence angle matters. This isn’t pre-recorded audio clips triggered by heart rate thresholds. The system generates natural language responses based on your specific data. Two people doing the same run get different coaching. Someone who crushed their rings all week gets different feedback than someone coming off three rest days.

The Redesigned Workout App

Workout Buddy gets the headlines, but the Workout app redesign might matter more for daily training.

Apple gutted the old interface and rebuilt it. The highlights:

Pacer is the one I use most. Set a target pace for running or cycling and Pacer gives you real-time visual and haptic feedback. Fall behind pace, you feel a tap and see a red indicator. Pull ahead, green. Simple. But the implementation is smoother than Garmin’s virtual partner or any third-party pacer I’ve used. The haptics are precise enough that I stopped looking at my wrist during interval runs.

Race Route lets you save a GPS route and race against your previous time. Strava has done this forever. But having it native on the watch, without phone dependency, with Workout Buddy coaching you through pace differentials against your PR? That’s the kind of integration only Apple can pull off.

Custom Workouts got a major upgrade. You can build interval structures with warm-up, work, rest, and cooldown blocks. Set targets by heart rate zone, pace, or time. It’s still not as flexible as what Garmin offers, but it’s a massive leap from the old “start an open workout and figure it out” approach.

What I Used It For

Four weeks of beta testing across mixed training:

• Running: 4 days/week, mix of easy runs and intervals (25-40 miles/week)
• Strength: 3 days/week in a home gym
• Cycling: 1-2 outdoor rides/week

I wore an Apple Watch Ultra 2 as my primary device. Compared coaching quality against URUNN for running and Fitbod for strength work.

The Coaching: What Works

It Actually Knows When to Shut Up

The biggest surprise. Most AI coaches overcommunicate. Every rep, every split, constant noise. Workout Buddy is quieter than expected.

During easy runs, it might speak twice in 30 minutes. “Your heart rate is in zone 2. Good easy day.” Then silence until something meaningful changes. During intervals, it’s more active. “Last interval was 6:45 pace, down from 6:52 on the previous one. One more.”

The density of coaching scales with workout intensity. That’s smart design. When I’m grinding through the last rep of a heavy set, I don’t want commentary. When I’m fading on interval number six, a data-driven nudge helps.

Activity Ring Context Is Surprisingly Useful

Workout Buddy references your weekly Activity ring data in its coaching. Monday morning after a lazy weekend: “You’re 340 calories behind your weekly average. Let’s make this count.” Friday after four solid training days: “Strong week. This is a good day to keep intensity moderate.”

Is it a big deal? No. But it bridges the gap between the Workout app (single-session focused) and the Activity app (daily/weekly tracking) in a way Apple never managed before. Your watch finally connects the dots between individual workouts and weekly training load.

Spoken Feedback Beats Screen Glances

Reading pace data on a watch screen mid-run is annoying. Squinting at tiny numbers while bouncing down a trail. Workout Buddy reads your metrics out loud at moments when the data is relevant. Approaching a mile split, it speaks your average pace. Heart rate spiking above your set zone, it warns you.

I started running with fewer screen checks. That alone made runs more enjoyable.

The Coaching: What Doesn’t Work

No Programming. None.

Workout Buddy coaches you during workouts. It does not plan workouts. It does not program training blocks. It does not periodize.

If you need “what should I do today?” guidance, Workout Buddy has nothing. It only activates once you’ve started a session. The gap between “AI motivation during workouts” and “AI training programming” is massive, and Apple chose the easier problem.

Dedicated AI coaches like URUNN and Runna still own the programming space. They tell you what to do, when to do it, and adjust the plan based on your compliance and performance. Workout Buddy cheers you on while you follow someone else’s plan. Or no plan at all.

Strength Training Coaching Is Weak

Running and cycling get detailed pace, heart rate zone, and split analysis. Strength training gets generic heart rate commentary.

“Heart rate elevated. Good intensity.” Thanks, I’m doing heavy squats. Of course it’s elevated.

The watch can’t count reps accurately (it tries, it’s inconsistent), doesn’t know what exercise you’re doing unless you manually log it, and can’t assess form. For strength athletes, Workout Buddy adds almost nothing. Fitbod’s exercise-specific adaptation and auto-progression remain far ahead.

Personalization Has a Ceiling

After four weeks, the coaching started feeling repetitive. The same pace comparisons, the same heart rate zone callouts, the same Activity ring references, the same post-workout summaries. The system draws from a limited pool of coaching templates and fills in your numbers.

It’s personalized in the sense that it uses your data. It’s not personalized in the sense that it learns your preferences, adjusts coaching style, or gets smarter about what feedback you actually respond to. Week one felt magical. Week four felt like a smart notification system.

Series 11 Hardware: The Other Stuff

The Apple Watch Series 11 ships alongside watchOS 26 with two health additions that matter for training context.

Hypertension notifications use the blood pressure sensor (introduced on Series 10 but limited to trend tracking) to alert you when readings suggest elevated blood pressure over time. This isn’t a blood pressure monitor. It’s a trend detector that tells you to see a doctor. Useful if you have risk factors. Not a training tool.

Sleep score finally arrives. A single number (0-100) summarizing sleep quality based on duration, stages, disruptions, and respiratory rate. Oura has had this for years. Whoop has had this for years. Apple is late. But for people who won’t wear a ring or a Whoop band, having it on the watch they already own matters.

Neither feature changes the fitness coaching equation. But the sleep score feeds into Workout Buddy’s context. Bad sleep score? “Recovery may be limited today. Consider an easier session.” That’s a connection Oura can’t make because Oura doesn’t run your workouts.

Workout Buddy vs. Dedicated AI Coaches

Here’s the honest comparison.

Feature	Workout Buddy	URUNN/Runna	Fitbod
Mid-workout coaching	Excellent	Good	None
Training programming	None	Excellent	Excellent
Periodization	None	Yes	Yes
Adapts to progress	Minimal	Yes	Yes
Price	Free (with watch)	$0-15/month	$80/year
Strength training	Weak	None	Excellent
Running specificity	Good	Excellent	None

Workout Buddy is a coaching layer, not a coaching replacement. The best setup right now: use a dedicated app for programming and let Workout Buddy handle real-time motivation on top.

URUNN for your running plan + Workout Buddy for spoken pace coaching during sessions. Fitbod for your strength programming + ignore Workout Buddy during lifts. That’s the stack that makes sense.

Who This Changes Things For

Casual Exercisers: Big Win

If you own an Apple Watch and work out 3-4 times a week without following a structured program, Workout Buddy is genuinely useful. It’s the first time the watch feels like it’s coaching you rather than just recording you. No subscription, no setup.

For the people already struggling with fitness app obsession, Workout Buddy’s lighter touch might actually be healthier than the data overload of dedicated tracking apps.

Competitive Runners: Moderate Win

Pacer and Race Route are solid additions. The spoken coaching during tempo runs and intervals adds value. But serious runners already have Garmin or COROS watches with deeper running metrics (running power, ground contact time, vertical oscillation). Workout Buddy doesn’t close that gap.

Strength Athletes: Minimal Impact

Until Apple Watch can identify exercises, count reps accurately, and track progressive overload, Workout Buddy is background noise for lifters. Stick with Fitbod or MacroFactor Workouts for actual strength programming.

People Who Killed Their Mulberry Hopes

If you read our Project Mulberry alternatives piece and felt disappointed, Workout Buddy is partial consolation. It delivers one slice of what Mulberry promised: AI-powered, personalized coaching using your health data. The nutrition guidance, sleep optimization protocols, and mental health components? Still missing. Still need the alternative stack we recommended.

Free vs. Paid Comparison

Workout Buddy is free. That changes the math entirely.

Every AI fitness coach charges a subscription. URUNN has a free tier but locks adaptive features behind a paywall. Runna is $15/month. Fitbod is $80/year. You’re paying $80-180 annually for coaching that Workout Buddy partially replaces at zero cost.

The catch: “partially” is doing heavy lifting in that sentence. Workout Buddy’s free mid-workout motivation doesn’t replace paid programming. But for someone choosing between “no coaching” and “Workout Buddy,” the gap is huge. Apple just made decent AI fitness coaching free for anyone with a recent Apple Watch.

The Bottom Line

Workout Buddy is the best free AI fitness coaching available. The mid-workout spoken feedback is genuinely useful for cardio, the redesigned Workout app is Apple’s best version yet, and the Activity ring integration finally makes your training history feel connected.

But it’s coaching support, not a coach. It motivates during sessions. It doesn’t plan them. For structured training, you still need dedicated apps.

Get excited about: Pacer, Race Route, spoken coaching during runs, zero subscription cost.

Don’t expect: Training plans, strength training intelligence, deep personalization that evolves over time.

The real story isn’t Workout Buddy alone. It’s that Apple shipped a competent AI coaching layer three months after killing its ambitious AI health project. That suggests more is coming. watchOS 27 might add programming. Or Apple might acquire someone who already does it well. For now, Workout Buddy is a strong v1 that makes your Apple Watch smarter during the workout itself.

Pair it with a real training app and you’ve got something close to what Mulberry was supposed to be. For free.

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Tested over 4 weeks on Apple Watch Ultra 2 running the watchOS 26 developer beta. Running, cycling, and strength training sessions. Final release may differ from beta experience.