Fitness AI vs Zing vs Planfit vs SHRED (2026): Price, AI, Devices

Four apps on the App Store sell themselves as AI workout planners: Fitness AI, Zing AI, Planfit and SHRED. Between them they carry 135,307 US App Store ratings.¹²³⁴ The company behind Fitness AI writes its name as one word, FitnessAI, but the app is listed as “Fitness AI Gym Workout Planner”.¹

The word “AI” tells you very little here. What separates these apps is what the AI is fed before it writes your next workout. Fitness AI works from the weights and reps you log. Planfit works from your gym’s equipment and your training history. Zing works from a daily check-in and your phone’s camera. SHRED adapts programs that human coaches wrote.¹⁵²⁴

We make SensAI, an AI coaching app, so it appears below as a fifth column, along with the places where each of the four beats it. Every price, limit and feature below was checked against each app’s US App Store listing and the developer’s own pages on 5 October 2026.

Which is the best AI workout app: Fitness AI, Zing, Planfit or SHRED?

Planfit is the best free AI workout app of the four: its AI plan is free “for a lifetime”. Fitness AI is the simplest sets, reps and weight planner, at $59.99–$89.99 a year. Zing AI ($18.99/mo) adds camera form tracking, a daily check-in and Les Mills classes. SHRED ($119.99/yr) runs coach-built programs adjusted by AI.³¹²⁶

	Fitness AI	Zing AI	Planfit	SHRED	SensAI
Built for	Gym and home strength, 5–30 minute sessions7	Home and gym; strength, HIIT, stretching, recovery2	Gym-first, “for gym beginners”5	Gym and home programs, plus HIIT, yoga and boxing classes4	Conversational AI coaching with Apple Health data89
What the AI adjusts from	Logged weights and reps1	Body data, daily check-in (energy, mood, sleep), tests, camera2	Profile, gym equipment, training history35	Coach-built programs plus your performance4	What you did, how you recovered, what you tell it8
Monthly price (US)	$9.99–$19.991	$18.992	$11.99–$14.993	$19.996	$6.9910
Yearly price (US)	$59.99–$89.991	No yearly plan labelled; 3 months $29.992	$79.99–$89.993	$119.996	$69.9910
Free tier	Not published	Not published	Yes: plan, reps and weights, log3	Yes, with “No Personalized Programming” and “No AI Progression”6	No (7 days of full access10)
Apple Watch	Yes (watchOS 9.01)	Yes (watchOS 9.02)	Premium only (watchOS 8.33)	Yes (watchOS 10.04)	Yes (watchOS 26.010)
Android	Yes, since November 20241112	Yes12	Yes12	Yes12	No
App Store rating (US)	4.7 from 55,9541	4.8 from 30,7542	4.8 from 8,2143	4.8 from 40,3854	4.6 from 3610

Prices and ratings from the US App Store and each developer’s website, 5 October 2026, before tax. Ranges cover the different offers the App Store lists.

All four run on Android and carry thousands to tens of thousands of App Store ratings. SensAI has 36, and runs only on iPhone and Apple Watch.¹²¹⁰ For a wider field of apps, see our 10-app roundup of the best AI workout apps.

How much do Fitness AI, Zing, Planfit and SHRED cost?

Fitness AI costs $9.99–$19.99 a month or $59.99–$89.99 a year. Zing costs $18.99 a month or $29.99 for three months. Planfit Premium costs $11.99–$14.99 a month or $79.99–$89.99 a year, and Planfit has a free tier. SHRED costs $19.99 a month or $119.99 a year. SensAI costs $6.99 a month or $69.99 a year.¹²³⁶¹⁰

Plan	Fitness AI	Zing	Planfit	SHRED
Free	Not published	Not published	Yes3	Yes, limited6
Weekly	$3.991	Mentioned in the listing; price not labelled2	None listed	$9.99, App Store item4
Monthly	$9.99 / $14.99 / $19.991	$18.992	$11.99 / $12.99 / $14.993	$19.99 on the website;6 $12.99, App Store item4
3 months	$24.99 / $44.99 (“Quarterly”1)	$29.992	None listed	None listed
Yearly	$59.99 / $89.991	Not labelled; unlabelled Premium items at $39.99 and $59.992	$79.99 / $87.99 / $89.993	$119.99 on the website;6 $99.99 “SHRED UNLIMITED”, App Store item4
Trial	Not published	Not published	7 days on Premium;3 on the web, annual plan only5	7 days with the annual plan6
Other	None listed	Body Scan Report $19.99, one-off2	Student annual $79.99;3 “7-day 100% money-back guarantee” on web purchases5	“Up to 30% Off” for military, first responders, medical professionals, teachers and students6

US App Store in-app purchase lists and developer websites, 5 October 2026. The App Store shows up to 10 purchase items without full plan labels, so the price you see at the paywall may differ.

Three details are easy to miss. SHRED’s “Just $9.99/month” headline is its yearly plan, “billed annually” at $119.99.⁶ Planfit’s Apple Watch app is a Premium feature, not part of the free tier.³ And none of the four says which of its listed prices your paywall will show, so a range is the honest answer for every one of them.

What do they cost over one and three years?

On the lowest-priced labelled plan, three years costs $179.97–$269.97 for Fitness AI, $239.97–$269.97 for Planfit Premium, $359.88 for Zing on its 3-month plan, $359.97 for SHRED and $209.97 for SensAI. Paid monthly instead, a year of SHRED costs $239.88. Planfit’s free tier costs nothing at all.¹³²⁶¹⁰

	1 year (lowest-priced labelled plan)	1 year (monthly plan)	3 years (lowest-priced labelled plan)
Fitness AI	$59.99–$89.99	$119.88–$239.88	$179.97–$269.97
Zing	$119.96 (4 × 3-month)	$227.88	$359.88
Planfit Premium	$79.99–$89.99	$143.88–$179.88	$239.97–$269.97
SHRED	$119.99	$239.88	$359.97
SensAI	$69.99	$83.88	$209.97

Yearly price × 3, monthly price × 12, Zing’s 3-month price × 4; assumes renewal at the listed price, before tax and introductory offers.

The honest ranking: Fitness AI’s $59.99 Annual Membership is the lowest labelled yearly price of the five, $10 below SensAI’s $69.99. SensAI has the lowest monthly price, at $6.99.¹¹⁰

Which fitness AI app is free?

Planfit is the only one of the four whose free tier includes an AI workout plan. Its App Store listing promises a planner “with the right reps & weights for your goals”, a machine guide and a workout log, free “for a lifetime”. SHRED has a free tier without AI progression. Fitness AI and Zing don’t publish a free tier.³⁶⁷²

Planfit splits its App Store listing into two lists. “Free features for a lifetime” covers the personal trainer and planner “with the right reps & weights for your goals”, the “Machine / Equipment Guide”, the “Workout log & tracker” and the community. “Premium features with a 7-day free trial” covers the “Real-time AI Coach”, “Muscle Recovery Tracking & Analysis”, “Exercise Performance Tracking & Analysis” and the Apple Watch app.³ Its website FAQ is just as direct: the “core features — AI workout plans, exercise guides, and workout tracking — are completely free to use forever.”⁵

SHRED’s free plan costs “$0 /forever”, with “Limited Workout Library Access”, “No Personalized Programming” and “No AI Progression”. The AI part is what you pay for.⁶

Fitness AI’s website says “Get Started For Free”, but it doesn’t publish what stays free after that, or how long its trial lasts.⁷ Zing doesn’t list free features or a trial length on its App Store page.²

SensAI has no free tier. New accounts get 7 days of full access, and the App Store listing says “No subscription required to start.”¹⁰

App	Free tier	What’s free	What needs paying
Planfit	Yes3	AI plan with reps and weights, equipment guide, workout log, community	Real-time AI Coach, recovery and performance analysis, Apple Watch app
SHRED	Yes6	Limited workout library, basic tracking, exercise demos	Personalized programming, AI progression
Fitness AI	Not published7	Not published	Membership, from $3.99 a week1
Zing	Not published2	Not published	Zing Premium, from $18.99 a month
SensAI	No10	7 days of full access	Everything after day 7, $6.99 a month

What does each fitness AI app actually read before it writes your workout?

Fitness AI reads the weights and reps you log. Planfit reads your profile, your gym’s equipment and your training history. Zing reads your body data and background, a daily check-in on energy, mood and sleep, fitness tests and your phone camera. SHRED adapts coach-built programs from your performance. SensAI reads Apple Health, with HRV from Apple Watch only.¹⁵²⁴⁹

	Fitness AI	Zing	Planfit	SHRED	SensAI
Starting inputs	Your equipment and strength-training history1	“Unique body data, fitness background, and lifestyle”; Fitness and Flexibility Tests2	“Fitness level, goals, available equipment, schedule, and training history”5	A training path written by coaches4	What you tell Coach, plus Apple Health data89
Ongoing inputs	Every logged set: it “automatically optimizes … sets, reps and weights … every time you work out”1	Daily check-in on “energy levels, mood, and sleep”; “tracks muscle fatigue levels”2	Logged workouts, “progress and feedback”; “Is a machine busy?” swaps53	“How hard you push, how you recover”4	“What you actually did and how you recovered”8
Camera or scan	3D BodyScan for progress7	Zing Vision form tracking; AI Body Scan2	Scan a body-composition sheet (Sep 20263)	Not listed	Not listed
Chat or voice	Not listed	Chat can edit the plan (“Add cardio to my plan”13)	Voice coaching;5 Planfit GPT, a ChatGPT-based trainer launched in early 202414	CoachAI audio and chat15	“Modify workouts mid-session with natural language”8
Wearable data as a stated input	Apple Watch: “Sync your performance automatically for accurate training data”7	Not listed	Not listed	Not listed	Sleep, heart rate and workouts from Apple Health; HRV from Apple Watch only9
How it changes the plan	Sets, reps and weight per exercise1	“Adjusting your workout plan in real-time”2	“Our AI calculates the precise weight and repetitions”3	“Automatically adjusts reps, sets, rest, and intensity”4	“Weekly regeneration” and mid-session changes8

From each App Store listing and developer site, 5 October 2026. “Not listed” means the developer does not state it, not that the app cannot do it.

Fitness AI is the purest example of a logged-lift planner. “Log your exercises and FitnessAI’s algorithm will do the rest,” its listing says.¹ The company’s own blog tells users: “If you notice a weight that you know will be too light or too heavy for you, change it!”¹⁶ That is good advice for any app in this category. A planner that learns from your logs needs a few sessions of real numbers before its suggestions settle.

Zing leans furthest toward what you tell it. Its coach “checks in daily about your energy levels, mood, and sleep”, and you can type changes into the chat or upload a workout photo for form tips.²¹³ Planfit sits between the two, building a plan around the equipment at your gym and adapting it “based on your progress and feedback”.⁵ For the mechanics behind all of these, see how AI workout generators work.

Which AI workout app uses my sleep or heart rate data?

Zing asks about your sleep in a daily check-in. SHRED says it keeps “recovery metrics” in sync with Apple Health but doesn’t say which ones. None of the four lists HRV as a programming input. SensAI reads sleep and heart rate from any device that writes to Apple Health, and HRV from Apple Watch only.²⁴⁹

Planfit’s “Muscle Recovery Tracking & Analysis” is a Premium feature.³ SHRED’s Apple Watch app will “track heart rate”, and SHRED added heart-rate support for AirPods Pro 3 in December 2025.⁴ Neither says those readings change your program.

SensAI reads Apple Health only. It does not link to Garmin, Oura or WHOOP accounts; your device’s own app writes to Apple Health, and SensAI reads from there. Apple Watch is the only device that shares HRV with it, and vendor scores such as Readiness, Recovery, Strain and Body Battery never cross.⁹ In the Help Center’s words: “Sleep and overnight heart rate from your device shape how hard Coach asks you to push on a given day.”⁹ To check what your device shares, read how to connect a wearable to SensAI through Apple Health.

How much data do these apps say their AI learned from?

Each company quotes a different training dataset, and two contradict themselves across their own pages. Fitness AI cites 5.9 million workouts, 40,000 lifters and 100 million sessions. Planfit cites 16 million workouts, about 60 million records, 80 million data points and 87 million logged workouts or exercises, depending on the page.^17351714

App	Claim	Where it says so
Fitness AI	“Based on 5.9M workouts”	App Store listing1
Fitness AI	“40k weight lifters and gym goers over a 3-year period”	App Store listing1
Fitness AI	“Built on 100M+ training sessions from real lifters”	fitnessai.com7
Planfit	“80 million+ gym workout data points”	App Store listing3
Planfit	“87M+ Workouts Logged”	planfit.ai home page5
Planfit	“16M+ workouts logged”, “87M+ exercises logged”, “300M+ sets recorded”	planfit.ai About page17
Planfit	“about 60 million exercise records”	KED Global, January 202514
Zing	“7.5M+ real workouts from 850,000+ paying users”	partner.zing.coach18
SHRED	“Refined by data from millions of workouts”	App Store listing4

Company claims as published, checked 5 October 2026. None is independently audited.

A bigger dataset is a company claim. It says nothing about whether the plan written for you is any good, which is what the research below tests.

Are AI-generated workout plans any good?

Sport scientists rate AI-generated training plans as reproducible but only “moderate” in quality. In two 2025 Biology of Sport studies rated by coaching experts, one found more detailed inputs produced better-rated plans, and the other concluded that expert supervision is still needed because the models “cannot account for individual responses to training”.¹⁹²⁰

Study	How plans were judged	What was tested	Main finding
Havers et al., 202519	12 coaching experts	GPT-4 and Google Gemini hypertrophy plans	Reproducible: 27 of 28 items showed no difference between repeated plans. GPT-4 rated higher. More detailed prompts produced higher-rated plans
Havers et al., 202520	10 coaches, 27 criteria	GPT-3.5 (ChatGPT and Microsoft Copilot) and Gemini, hypertrophy and strength plans	Overall quality “moderate”
Washif et al., 202421	Compared against established guidelines	ChatGPT (GPT-3.5 and GPT-4) resistance training programs	Programs were “objectively similar regardless of sex” and “likely require additional fine-tuning”
Genç et al., 202522	Expert rubric scoring	ChatGPT-3.5, 4o and 4.1, 12-week programs	ChatGPT-4.1 scored best, then 4o, then 3.5

Peter Düking, a sport scientist at Technische Universität Braunschweig, and Billy Sperlich of the University of Würzburg were senior authors on both Biology of Sport studies. Havers, Düking and colleagues concluded that AI plans “can serve as an initial framework”, but that “expert supervision remains crucial to refine these plans, as LLMs cannot account for individual responses to training”.²⁰ Their first study adds the practical lesson: “quality improves with more detailed input”.¹⁹

Jad Adrian Washif, a sport scientist at the National Sports Institute of Malaysia, reached the same place with his colleagues: “ChatGPT may serve as a complementary tool for writing ‘draft’ programme, but likely requires human expertise to maximise training programme effectiveness.”²¹ The 2025 study by Genç and colleagues ended on the same note: “the involvement of qualified human expertise remains essential.”²²

One caveat matters. These studies tested general chatbots, not these four apps, and we found no peer-reviewed trial of Fitness AI, Zing, Planfit or SHRED. KED Global reports that a large language model is “the main machine-learning algorithm used to operate the app”, so the chatbot research bears most directly on it.¹⁴ For a closer look at chatbot-written plans, see can ChatGPT write a good workout plan?

What should a good AI workout plan get right?

Whatever writes the plan, the research points to the same few things: enough weekly sets per muscle, sets taken reasonably close to failure, steady progression in load or reps, and room to adjust for the day. Check any AI workout app against these before trusting its “optimized” numbers.^2324252627

Principle	What the research found	Source
Weekly volume	Each extra weekly set added about 0.37% to muscle gain, and higher volume beat lower by 3.9% (15 studies). A 2026 meta-regression of 67 studies and 2,058 participants found gains rise with volume, with diminishing returns that are more pronounced for strength	Schoenfeld et al., 2017;23 Pelland et al., 202624
Effort	Only a “trivial advantage” for training to set failure over stopping short (effect size 0.19, 95% CI 0.00–0.37)	Refalo et al., 202325
Progression	Adding reps or adding load both built muscle in 43 trained lifters over 8 weeks	Plotkin et al., 202226
Adjusting for the day	Every autoregulation protocol raised one-rep max (1RM) across 14 studies and 356 participants. RPE-based loading showed a small, non-significant squat advantage (+17.05 vs +13.91 kg) over percentage loading	Larsen et al., 2021;27 Helms et al., 201828

Every app in this comparison automates “progressive overload” in some form. The Plotkin trial is a useful reminder that progression does not have to mean more weight every session: adding reps at the same load worked too.²⁶ A widely used tool for rating effort, the reps-in-reserve rating of perceived exertion (RPE) scale, was published by Michael Zourdos, Eric Helms and colleagues in 2016.²⁹

Brad Schoenfeld, PhD, of Lehman College, City University of New York, led the volume meta-analysis above. In a 2014 interview about program design in general, not about apps, he said that optimizing training variables “is not a cookie-cutter process” and that “substantial fine-tuning must be done to derive best results on an individual basis.”³⁰²³ That is a fair test for any AI planner: does it fine-tune for you, or hand you a template with your name on it?

Does it matter whether the AI reads your logs, your check-ins or your watch?

Probably, but the evidence cuts both ways. A 2016 review of 56 studies found athletes’ own ratings tracked training load more sensitively than objective measures such as heart rate. A 2021 meta-regression of lifestyle apps found personalization from automatically captured data was linked to larger effects than self-reported data. Both kinds of input carry signal.³¹³²

Saw, Main and Gastin’s review found that subjective measures reflected training load “with superior sensitivity and consistency than objective measures”.³¹ That is the honest point in Zing’s favour. A daily question about energy, mood and sleep is an evidence-aligned design, not a gimmick.

Eric Helms, PhD, of the Sports Performance Research Institute New Zealand at Auckland University of Technology, co-authored the reps-in-reserve RPE scale.²⁹²⁸ He describes the idea plainly: “Autoregulation, simply put, is just a structured approach for embedding a respect for individual variation within a program.”³³ He also notes that “well-designed subjective questionnaires relating to readiness and fatigue were more sensitive to alterations in training stress than measures of hormonal status, immune function, muscle damage, inflammation, and heart rate and variance measurements.”³³ That argues against relying on HRV alone, SensAI’s included.

The other side comes from Tong and colleagues, who pooled 31 personalized app and tracker interventions (n=77,243). Interventions that personalized from system-captured data were associated with higher effectiveness than those using user-reported data (standardized mean difference 1.48, 95% CI 0.76–2.19).³² That research covers lifestyle behaviours such as activity and diet, not strength training, so treat it as a pointer rather than proof.

Put together, Fitness AI uses what you lifted. Zing uses what you tell it, plus the camera. SensAI combines what you did and what you tell it with Apple Health data. That is also why SensAI pairs Apple Health data with a coach you can talk to, rather than relying on a watch reading alone.⁸⁹ No study has compared these apps’ approaches head to head, so treat any readiness number as a guide, not a verdict.

Fitness AI review: is Fitness AI worth it in 2026?

Fitness AI is worth it if you want the simplest possible “tell me the sets, reps and weight” planner for home or gym training. It costs $59.99–$89.99 a year and runs on iPhone, Apple Watch and, since November 2024, Android. It is less suited to anyone who wants a coach to talk to.¹¹¹

Fitness AI has been on the App Store since 20 December 2018 and holds 4.7 stars from 55,954 US ratings; version 24.1 shipped on 30 September 2026.¹ The pitch is narrow and clear: an algorithm to “guide you through the perfect set, rep and weight combination”, “high rep modes” for toning, and workouts built from “whatever equipment you have available”.¹ Its website promises 5–30 minute sessions and a 3D BodyScan for tracking progress.⁷

The listing also claims that “our innovative algorithm is sure to out-perform any human personal trainer”.¹ We found no published study that supports that for this or any other app, and the chatbot studies above point the other way: their authors found human expertise still essential.²⁰²²

Fitness AI is not iPhone-only: it launched on Android on 25 November 2024.¹¹ On Google Play it holds 4.5 stars with 50K+ downloads.¹² Karetha Strand, then CEO of owner Appex Group, said at launch: “We’re excited to announce the launch of FitnessAI on Android, marking a significant milestone in our mission to bring intelligent strength training to a broader audience”.¹¹

Ownership is worth knowing. Jake Mor founded FitnessAI in 2019, and it went through Y Combinator’s Winter 2020 batch; YC now lists it as “Acquired”.³⁴ It is owned by Appex Group, Inc., a studio with “roots in Boston, MA” that calls itself “a mobile application studio specializing in building, scaling, and acquiring innovative apps”. Kerri Walsh is now its CEO, and Strand is listed as an advisor.¹¹³⁵ FitnessAI Inc. is also the App Store seller of DietBet: Lose Weight & Win!, and the Fitness AI website now promotes “Structured Challenges. Real Stakes.” with “rewards on the line”.¹⁷

The 2026 updates have been steady rather than dramatic: “a new training reset algorithm for more accurate, personalized progress” in April, a redesigned Progress tab in August and Achievements at the end of August.¹

The verdict: at the $59.99 Annual Membership, Fitness AI is good value if logged-lift progression is all you need. It doesn’t publish its trial length, so check the paywall before you subscribe.¹

Fitness AI vs Planfit: which is better?

Planfit is better if you want to start free or train in a busy commercial gym: its free tier includes the AI plan, and it maps your gym’s equipment. Fitness AI is better for short sessions at home or in a gym, and its lowest annual plan ($59.99) undercuts Planfit Premium ($79.99).³¹⁷⁷¹

	Fitness AI	Planfit
Free tier	Not published7	Yes, including the AI plan3
Monthly price	$9.99–$19.991	$11.99–$14.993
Yearly price	$59.99–$89.991	$79.99–$89.993
Apple Watch	Yes1	Premium only3
Gym mapping	Not listed	“245,000+ gyms across 150 countries”, “9M+ pieces of equipment mapped” (company claims17)
Session length	5–30 minutes7	Not published
Android	Yes, 50K+ downloads12	Yes, 1M+ downloads12
App Store rating	4.7 from 55,9541	4.8 from 8,2143

US App Store, Google Play and developer websites, 5 October 2026.

Planfit’s most practical feature is the one built for crowded gyms: “Get alternative plan: Is a machine busy?”, after which the app “suggests the best alternative exercise instantly”.³ It also leans hardest on language models. In early 2024 it launched Planfit GPT, a ChatGPT-based personal trainer.¹⁴

Planfit is a Korean company, founded in June 2021 by CEO Baek Hyeonwoo.¹⁷¹⁴ “Our goal is to help our members easily maintain their training for longer periods,” he told KED Global.¹⁴ On Google Play it has more than 1M downloads, against Fitness AI’s 50K+.¹²

Zing vs Planfit: which is better?

Zing is better for home workouts, camera form feedback and class-style training, including Les Mills programs. Planfit is better for structured gym lifting on a budget, with a free AI plan and Premium from $79.99 a year, against Zing’s $18.99 a month.²³

Zing’s distinguishing features use your phone’s camera. Zing Vision “uses your smartphone’s camera to track movements in real-time”, and AI Body Scan estimates body composition from photos, which Zing says “are promptly deleted for privacy”.² It builds workouts “from almost 500 exercises” across “strength, HIIT, stretching, and recovery”, and since August 2025 it has offered four coach personalities, from “Drill Sergeant” to “Precision Pro”.² For how camera form checking compares across apps, see our AI form-check app comparison.

Don’t assume Zing is only for the living room. According to its Les Mills announcement, 62% of Zing Coach users train in the gym.³⁶

Planfit’s live coaching sits behind the paywall: the “Real-time AI Coach (countdown reps, rest times, and detailed workout guides)” is a Premium feature.³ On Android, Zing has 500K+ downloads and Planfit 1M+.¹²

Fitness AI vs Zing: which is better?

Fitness AI is better if you lift and want weights and reps set for you from your own logs, for $59.99–$89.99 a year. Zing is better if you want a coach that checks in daily on energy, mood and sleep, watches your form through the camera and mixes strength with HIIT and stretching.¹²

Zing Coach is led by CEO Anton Marchanka and backed by the health-tech company Palta.³⁶³⁷ It raised a US$10 million Series A in June 2024, with Zubr as lead investor.³⁸ In 2026 it signed two partnerships: Paris Saint-Germain in January, running until 2027, and Les Mills in March.³⁷³⁶

The Les Mills deal brought “19 globally loved programs and over 200 workouts” into the app.² Marina Nola, Chief Digital Distribution Officer at Les Mills, summed up the pitch: “members get the motivation of human-led workouts and the flexibility of AI, the best of both worlds.”³⁶

One observation, stated without interpretation: on 5 October 2026, zing.coach redirected to a partner site for gyms and apps, titled “ZNG COACH”.¹⁸ The consumer app was updated on 9 September 2026, and Zing’s methodology and fitness library pages still load.²

SHRED vs Fitness AI: which is better for muscle gain?

For muscle gain, SHRED suits lifters who want a program written by coaches, with AI adjusting sets, reps, rest and intensity. Fitness AI suits lifters who want the app to set the numbers from their own logged lifts. No study has compared the two. SHRED costs more: $119.99 a year against $59.99–$89.99.⁴¹⁶

SHRED offers training paths in “hypertrophy, powerlifting, strength, bodyweight, or sculpting”, and says “every program is crafted by real coaches and refined by data from millions of workouts”.⁴ Premium covers “all 18 Training Styles” and includes “AI weight recommendations, weight logging, exercise and circuit alternatives”.³⁹ You can also talk back to the coach “to adjust your exercises, switch programs, or get nutrition advice”.⁴

Its AI layer arrived as CoachAI in September 2025, with workout audio and chat. “CoachAI represents the evolution from static content to a living intelligence system,” said founder and CEO Charlie Hale.¹⁵ Later updates added a Post-Workout Summary “enhanced with Apple Intelligence” and heart-rate tracking from AirPods Pro 3.⁴

SHRED is rated 4.8 from 40,385 US ratings, the highest average of the four on Apple’s unrounded figures.⁴ Fitness AI has more ratings, at 55,954.¹

For muscle gain specifically, whether you set SHRED against Fitness AI or against Fitbod, the app matters less than what it asks you to do. Both automate progression. What drives hypertrophy is enough weekly sets per muscle, taken reasonably close to failure, progressed over time, as the research table above shows.²³²⁵²⁶

Fitness AI vs Fitbod and Planfit vs Fitbod: how do they compare?

Fitbod has 286,570 US App Store ratings, more than Fitness AI, Zing, Planfit and SHRED combined (135,307), and needs iOS 18. If you are weighing Fitness AI vs Fitbod or Planfit vs Fitbod, both challengers set weights and reps from your history, run on older iPhones, and Planfit adds a free AI tier.⁴⁰¹³

Fitbod is rated 4.8, and its latest version, 8.35.0, shipped on 1 October 2026.⁴⁰ Fitness AI, Zing and SHRED need iOS 17.0 and Planfit iOS 15.1, so all four run on older iPhones than Fitbod does.¹²⁴³⁴⁰ For Fitbod’s pricing, features and how its algorithm works, see our full Fitbod review.

How do Fitness AI, Zing, Planfit and SHRED compare with SensAI?

Fitness AI, Zing, Planfit and SHRED are planners driven by your logs, check-ins, camera or coach-built programs. SensAI ($6.99/mo, $69.99/yr) is a conversational AI coach that reads Apple Health, with HRV from Apple Watch only, and regenerates your week from what you did and how you recovered. It runs on iPhone and Apple Watch only.¹⁰⁸⁹

App	Approach	Yearly price (US)	Free option	Android
Fitness AI	Sets, reps and weight from your logged lifts	$59.99–$89.991	Not published	Yes12
Zing	Daily check-in, camera form tracking, classes	No yearly plan labelled; $29.99 for 3 months2	Not published	Yes12
Planfit	Gym-equipment-aware plans from your history	$79.99–$89.993	Yes3	Yes12
SHRED	Coach-built programs adjusted by AI	$119.996	Yes, without AI progression6	Yes12
SensAI	Conversational AI coach using Apple Health data	$69.9910	None (7 days of full access10)	No (iPhone and Apple Watch app10)

Where Fitness AI, Zing, Planfit and SHRED beat SensAI

• All four run on Android, and each has thousands to tens of thousands of App Store ratings. SensAI is iPhone and Apple Watch only, with 36 ratings.¹²¹⁰
• All four also run on older iPhones, from iOS 15.1 to iOS 17.0, where SensAI needs iOS 26.¹²³⁴¹⁰
• Planfit has a free tier with an AI plan. SensAI offers 7 days of full access, then a subscription.³¹⁰
• Zing has camera form tracking (Zing Vision), an AI Body Scan and the Les Mills library of 19 programs and 200+ workouts. SensAI lists no camera form tracking or class library.²⁸
• SHRED has coach-built programs, studio classes, AirPods Pro 3 heart rate and the highest rating average of the group.⁴
• Fitness AI has the lowest labelled yearly price ($59.99) and 5-minute sessions.¹⁷

Where SensAI is different

SensAI is a coach you talk to. Its coach “follows along and adjusts the workout mid-session”, and you can “Modify workouts mid-session with natural language”.⁸ Between sessions it promises “Weekly regeneration based on what you actually did and how you recovered”.⁸

It also uses recovery data from Apple Health. “HRV and sleep quality inform daily programming and intensity,” with HRV coming from Apple Watch only; sleep and heart rate arrive from any device that writes to Apple Health.⁸⁹ None of the four lists HRV as a programming input. On Apple Watch, SensAI offers “Guided set-by-set tracking with rest timers, muscle group visuals, and real-time heart rate zones”.⁸ And it has the lowest monthly price of the five, at $6.99.¹⁰

To see what your watch or ring shares with SensAI, read how to connect a wearable to SensAI through Apple Health.

Do Fitness AI, Zing, Planfit and SHRED work with Apple Watch and Android?

All four run on iPhone, Android and Apple Watch, though Planfit’s Watch app is a Premium feature. All four connect to Apple Health, but none publishes the full list of data it reads from it. Fitness AI has been on Android since November 2024, which many comparison pages still miss.^12341211

	Fitness AI	Zing	Planfit	SHRED	SensAI
iPhone	iOS 17.0+1	iOS 17.0+2	iOS 15.1+3	iOS 17.0+4	iOS 26.0+10
Apple Watch	watchOS 9.0; in-workout features not detailed1	watchOS 9.0; a 2025 update clarified “Apple Watch connectivity during workouts”2	watchOS 8.3; Premium3	watchOS 10.0; “Log every rep, track heart rate, control music”4	watchOS 26.0; set-by-set tracking with real-time heart rate zones108
Android (Google Play)	4.5, 50K+ downloads12	4.7, 500K+12	4.7, 1M+12	4.5, 100K+12	No
iPad	Not on device list1	Not on device list2	Yes3	Yes4	Not on device list10
Apple Health	“Sync your FitnessAI workouts with Apple Health”; calorie tracking with Apple Health and Fitbit141	“Export exercise data and import fitness data and body measurements”2	“Sync your Planfit Data with Apple Health”; direction not stated3	“Activity, calories, and recovery metrics are always in sync”; data types not stated4	Reads Apple Health only; HRV from Apple Watch only9
Uses HRV or sleep to adjust training	Not listed	Sleep via daily self-report check-in; HRV not listed2	Not listed	Not listed	Yes: “HRV and sleep quality inform daily programming and intensity” (HRV from Apple Watch89)
Import from other apps	Not documented	Not documented	Not documented	Not documented	Roughly the last 30 days of Apple Health workouts9

Requirements from each US App Store listing and Google Play listing, 5 October 2026. “Not listed” or “Not documented” means the developer does not state it.

SensAI syncs roughly the last 30 days of Apple Health workouts, so recent sessions logged by your watch or another app show up alongside its own.⁹

What changed in Fitness AI, Zing, Planfit and SHRED in 2026?

Zing added Les Mills classes and a PSG partnership. Fitness AI shipped a new training-reset algorithm, a redesigned Progress tab and Achievements. SHRED added Build Your Own Workout and saved alternates. Planfit added body-composition-sheet scanning and, in its latest release, “even more personalized” workout recommendations.^23637143

Date	App	Change
6 Jan 2026	Zing	Paris Saint-Germain partnership announced, running until 202737
16 Mar 2026	Zing	Les Mills: “19 globally loved programs and over 200 workouts”, v1.121.02
20 Mar 2026	Fitness AI	Routine workouts count toward challenges, v16.01
20 Mar 2026	Zing	AirPlay support for Les Mills workouts, v1.121.12
25 Mar 2026	Zing	Les Mills partnership announced36
11 Apr 2026	Fitness AI	“A new training reset algorithm”, v17.01
12 Aug 2026	Fitness AI	Redesigned Progress tab, v22.01
25 Aug 2026	SHRED	“Build Your Own Workout”, v5.5.24
31 Aug 2026	Fitness AI	Achievements, v23.01
3 Sep 2026	SHRED	New equipment profiles start with all equipment enabled; Quick HIIT and Cardio in the Dynamic Island, v5.5.34
10 Sep 2026	Planfit	Scan a body-composition sheet, v3.236.43
22 Sep 2026	SHRED	Saved alternates, v5.5.44
28 Sep 2026	Planfit	Improved gym and equipment registration, v3.241.23
30 Sep 2026	Planfit	“Workout recommendations are now even more personalized”, v3.243.13
5 Oct 2026	Zing	zing.coach observed redirecting to the partner site “ZNG COACH”18

App Store version histories and company announcements, checked 5 October 2026.

Which is the best AI workout app for you?

Choose Planfit if you are new to the gym and want to start free. Choose Fitness AI for the simplest logged-lift planner at the lowest labelled yearly price. Choose Zing for home training, camera form feedback and classes. Choose SHRED for coach-written programs. Choose SensAI if you want to talk to a coach that reads your Apple Health data.³⁵¹²⁴⁸

Choose Fitness AI if you:

• Want weights and reps set for you from your own logs
• Train for 5–30 minutes at home or in a gym
• Want the $59.99 Annual Membership, or use Android

Choose Zing if you:

• Train mostly at home, or mix strength, HIIT and stretching
• Want camera form tracking, a body scan or Les Mills classes
• Like a daily check-in on energy, mood and sleep

Choose Planfit if you:

• Want an AI plan without paying anything
• Are new to the gym; its own site calls it an app “for gym beginners”
• Want alternatives on the spot when a machine is busy

Choose SHRED if you:

• Want programs written by coaches
• Want studio classes such as HIIT, yoga and boxing alongside lifting
• Use AirPods Pro 3 for heart rate

Choose SensAI if you:

• Want a coach you talk to, and want to change a session mid-workout in plain language
• Wear an Apple Watch and want HRV and sleep to shape how hard you train
• Use an iPhone running iOS 26

Frequently asked questions

Most questions about Fitness AI, Zing, Planfit and SHRED come down to price, free tiers and devices. Planfit has the most generous free tier, Fitness AI the lowest labelled yearly price at $59.99, and all four run on Android and Apple Watch. None of the four lists HRV as a programming input or documents an import option.³¹¹²

How much is Fitness AI per month?

On the US App Store, Fitness AI’s monthly memberships cost $9.99 to $19.99, with a $3.99 weekly option. Yearly plans cost $59.99 or $89.99. The app doesn’t publish which price your paywall will show.¹

Is Fitness AI free?

The website says “Get Started For Free”. It doesn’t publish what stays free after that, or how long the trial lasts, so check the paywall before you subscribe.⁷

Does Fitness AI work on Android?

Yes. Fitness AI launched on Android on 25 November 2024. On Google Play it holds 4.5 stars with 50K+ downloads.¹¹¹²

Does Fitness AI work with Apple Watch?

Yes. There is an Apple Watch app, which needs watchOS 9.0. Fitness AI doesn’t detail what the Watch app does during a workout.¹

Who owns Fitness AI (FitnessAI)?

Appex Group, Inc., an app studio with roots in Boston, whose CEO is Kerri Walsh. Jake Mor founded FitnessAI in 2019, and it was part of Y Combinator’s Winter 2020 batch. FitnessAI Inc. also sells DietBet on the App Store.^1135341

Is Planfit free?

Yes, for the AI plan with reps and weights, the equipment guide, the workout log and the community. Premium, from $11.99 a month or $79.99 a year, adds the Real-time AI Coach, recovery and performance tracking, and the Apple Watch app.³

Zing AI review: is Zing good for the gym or just home workouts?

Both. According to its Les Mills announcement, 62% of Zing Coach users train in the gym. Zing Premium costs $18.99 a month. Zing doesn’t list free features on its App Store page.³⁶²

How much does the SHRED app cost?

SHRED’s website lists $19.99 a month or $119.99 a year, with a 7-day trial on the annual plan. The free plan has “No AI Progression”. Military, first responders, medical professionals, teachers and students can get “Up to 30% Off”.⁶

Do any of these AI workout apps use HRV?

None of the four lists HRV as a programming input. Zing asks about sleep in a daily check-in. SensAI reads HRV from Apple Watch only, plus sleep and heart rate from any device that writes to Apple Health.²⁹

Can I import my workouts into Fitness AI, Zing, Planfit or SHRED?

None of the four documents an import option from other apps. If your history matters to you, check with the developer before you switch.

Is any AI workout app worth paying for in 2026?

Planfit’s free tier is the place to start. Pay when you need what the free tiers lack: Fitness AI’s logged-lift planner at $59.99–$89.99 a year, Zing’s camera tracking and classes at $18.99 a month, or SHRED’s coach-built programs at $119.99 a year.³¹²⁶

Whichever you pick, the research says an AI-written plan is a decent draft that still needs adjusting to the person following it.²⁰²¹ The best of these apps make that adjustment easy: they learn from your logs, ask how you feel, or let you swap an exercise when the gym is busy.

If you want that adjustment to come from talking to a coach, with your Apple Health data in the picture, that is what SensAI does, on iPhone and Apple Watch.

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References

Footnotes

1. FitnessAI Inc. “Fitness AI Gym Workout Planner.” Apple App Store listing (id1446224156) — “FitnessAI’s advanced training algorithm to guide you through the perfect set, rep and weight combination”; “Get results with whatever equipment you have available”; “Fitness AI automatically optimizes weight lifting sets, reps and weights for each exercise every time you work out”; “Build your workout based on your strength-training history. Log your exercises and FitnessAI’s algorithm will do the rest”; “high rep modes”; “Based on 5.9M workouts, our innovative algorithm is sure to out-perform any human personal trainer or fitness coach at the gym”; “Our algorithm is based on 40k weight lifters and gym goers over a 3-year period”; “Sync your FitnessAI workouts with Apple Health (activate in FitnessAI Settings -> HealthKit)”; in-app purchases Weekly Membership $3.99, Monthly Membership $9.99, Monthly Membership 3 $14.99, Monthly product $19.99, Quarterly product $24.99 and $44.99, Annual Membership $59.99, Annual Membership 3 $89.99; requires iOS 17.0, Apple Watch app requires watchOS 9.0; devices iPhone and Apple Watch; version 16.0 (March 20, 2026) “Your routine workouts now count toward challenges”; version 17.0 (April 11, 2026) “Introducing a new training reset algorithm for more accurate, personalized progress”; version 22.0 (August 12, 2026) “a redesigned Progress tab featuring new Body Activity and Strength Progress charts”; version 23.0 (August 31, 2026) “Introducing Achievements”; version 24.1 (September 30, 2026); first released December 20, 2018; 4.7 rating from 55,954 ratings; “More by FitnessAI Inc.” lists DietBet: Lose Weight & Win!. Accessed October 5, 2026. https://apps.apple.com/us/app/fitness-ai-gym-workout-planner/id1446224156 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴ ↩²⁵ ↩²⁶ ↩²⁷ ↩²⁸ ↩²⁹ ↩³⁰ ↩³¹ ↩³² ↩³³ ↩³⁴ ↩³⁵ ↩³⁶ ↩³⁷ ↩³⁸ ↩³⁹ ↩⁴⁰ ↩⁴¹ ↩⁴² ↩⁴³ ↩⁴⁴ ↩⁴⁵ ↩⁴⁶ ↩⁴⁷ ↩⁴⁸ ↩⁴⁹ ↩⁵⁰ ↩⁵¹ ↩⁵² ↩⁵³ ↩⁵⁴ ↩⁵⁵ ↩⁵⁶ ↩⁵⁷ ↩⁵⁸ ↩⁵⁹ ↩⁶⁰ ↩⁶¹

2. Zing Coach Inc. “Zing AI: Home & Gym Workouts.” Apple App Store listing (id1552207792) — “It checks in daily about your energy levels, mood, and sleep, adjusting your workout plan in real-time”; “Zing creates customized workout plans based on your unique body data, fitness background, and lifestyle”; “Zing Coach generates intuitive workouts from almost 500 exercises”; “It tracks muscle fatigue levels”; Zing Vision “uses your smartphone’s camera to track movements in real-time”; AI Body Scan, “Photos are promptly deleted for privacy”; Fitness Test and Flexibility Test; “strength, HIIT, stretching, and recovery”; “Zing integrates with HealthKit, allowing you to export exercise data and import fitness data and body measurements”; “Seamlessly integrate with Apple Watch and Apple Health”; “a wide range of subscription options … (3 months access renewal, weekly renewal, etc.)”; in-app purchases Zing Premium $18.99, Zing Premium 3 Months $29.99, Zing Premium $29.99, $39.99 and $59.99, Body Scan Report $19.99; requires iOS 17.0, Apple Watch app requires watchOS 9.0; devices iPhone and Apple Watch; version 1.113.0 (August 22, 2025) four AI coach personalities, “Drill Sergeant, Sassy Cheerleader, Thoughtful Ally, and Precision Pro”, and “We’ve also clarified the Apple Watch connectivity during workouts”; version 1.121.0 (March 16, 2026) Les Mills, “a premium content library with 19 globally loved programs and over 200 workouts”; version 1.121.1 (March 20, 2026) “improved AirPlay support for Les Mills workouts”; version 1.127.0 (September 9, 2026); first released April 5, 2021; 4.8 rating from 30,754 ratings. Accessed October 5, 2026. https://apps.apple.com/us/app/zing-ai-home-gym-workouts/id1552207792 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴ ↩²⁵ ↩²⁶ ↩²⁷ ↩²⁸ ↩²⁹ ↩³⁰ ↩³¹ ↩³² ↩³³ ↩³⁴ ↩³⁵ ↩³⁶ ↩³⁷ ↩³⁸ ↩³⁹ ↩⁴⁰ ↩⁴¹ ↩⁴² ↩⁴³ ↩⁴⁴ ↩⁴⁵ ↩⁴⁶ ↩⁴⁷ ↩⁴⁸ ↩⁴⁹

3. Planfit Inc. “Planfit AI Gym Workout Planner.” Apple App Store listing (id1511876936) — “Powered by 80 million+ gym workout data points, our AI planner creates a personalized workout plan tailored to your strength, goals, and even the equipment available at your gym”; “Free features for a lifetime: Personal fitness trainer & planner with the right reps & weights for your goals; Machine / Equipment Guide; Workout log & tracker; Fitness community”; “Premium features with a 7-day free trial: Real-time AI Coach (countdown reps, rest times, and detailed workout guides); Muscle Recovery Tracking & Analysis; Exercise Performance Tracking & Analysis; Apple watch Integration”; “Our AI calculates the precise weight and repetitions you need to push past plateaus safely”; “Get alternative plan: Is a machine busy? Don’t break your plan by yourself. Our AI workout planner suggests the best alternative exercise instantly”; “1,100+ exercise videos”; “HealthKit : Sync your Planfit Data with Apple Health”; in-app purchases Premium Monthly Plan A and C $11.99, Monthly Plan B $12.99, Premium Monthly Subscription $14.99, Annual Plan A and B $79.99, Student Annual Plan $79.99, Annual Plan E $87.99, Premium Annual Subscription $89.99; requires iOS 15.1, Apple Watch app requires watchOS 8.3; devices iPhone, iPad and Apple Watch; version 3.236.4 (September 10, 2026) “You can now scan your body composition sheet to automatically input your body composition data”; version 3.241.2 (September 28, 2026) “We’ve improved the process for registering gyms and equipment”; version 3.243.1 (September 30, 2026) “Workout recommendations are now even more personalized”; first released May 15, 2020; 4.8 rating from 8,214 ratings. Accessed October 5, 2026. https://apps.apple.com/us/app/planfit-ai-gym-workout-planner/id1511876936 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴ ↩²⁵ ↩²⁶ ↩²⁷ ↩²⁸ ↩²⁹ ↩³⁰ ↩³¹ ↩³² ↩³³ ↩³⁴ ↩³⁵ ↩³⁶ ↩³⁷ ↩³⁸ ↩³⁹ ↩⁴⁰ ↩⁴¹ ↩⁴² ↩⁴³ ↩⁴⁴ ↩⁴⁵ ↩⁴⁶ ↩⁴⁷ ↩⁴⁸ ↩⁴⁹ ↩⁵⁰ ↩⁵¹ ↩⁵² ↩⁵³

4. Shred Labs, LLC. “SHRED: Gym & Home Workouts.” Apple App Store listing (id1439828095) — “Explore expertly designed training paths in hypertrophy, powerlifting, strength, bodyweight, or sculpting. Every program is crafted by real coaches and refined by data from millions of workouts”; “SHRED’s AI learns your patterns—how hard you push, how you recover, and when to advance or pull back. It automatically adjusts reps, sets, rest, and intensity”; “TALK TO YOUR COACH … talk back to adjust your exercises, switch programs, or get nutrition advice”; “Log every rep, track heart rate, control music, and sync progress—all from your wrist. SHRED connects seamlessly with Apple Health so your activity, calories, and recovery metrics are always in sync”; “Studio Classes: HIIT, Yoga, Boxing, and more”; in-app purchases include Monthly Subscription $12.99, SHRED UNLIMITED $99.99, SHRED UNLIMITED (WEEKLY) $9.99, Shred Unlimited $19.99 and $119.99; requires iOS 17.0, Apple Watch app requires watchOS 10.0; devices iPhone, iPad and Apple Watch; version 5.3.2 (November 12, 2025) “Post-Workout Summary: Powered by CoachAI and enhanced with Apple Intelligence”; version 5.3.3 (December 1, 2025) “AirPods Pro 3 Heart Rate Integration”; version 5.5.2 (August 25, 2026) “Build Your Own Workout”; version 5.5.3 (September 3, 2026) “New equipment profiles now start with all equipment enabled” and “Quick HIIT and Cardio workouts now appear in the Dynamic Island”; version 5.5.4 (September 22, 2026) “Saved Alternates”; first released November 27, 2018; 4.8 rating from 40,385 ratings. Accessed October 5, 2026. https://apps.apple.com/us/app/shred-gym-home-workouts/id1439828095 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴ ↩²⁵ ↩²⁶ ↩²⁷ ↩²⁸ ↩²⁹ ↩³⁰ ↩³¹ ↩³² ↩³³ ↩³⁴

5. Planfit. Homepage and FAQ — “AI-powered personal training app for gym beginners”; “87M+ Workouts Logged”; “Planfit AI analyzes your fitness level, goals, available equipment, schedule, and training history to create a program tailored specifically to you. As you train, it adapts based on your progress and feedback”; “Planfit’s core features — AI workout plans, exercise guides, and workout tracking — are completely free to use forever”; “Voice Coaching”; web checkout: “The 7-day free trial comes with the annual plan” and “your 7-day 100% money-back guarantee starts at checkout”. Accessed October 5, 2026. https://planfit.ai ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴

6. SHRED. “Pricing.” Free “$0 /forever” with “Limited Workout Library Access”, “Basic Tracking Features”, “Standard Exercise Demos”, “No Personalized Programming”, “No AI Progression”; Annual “$119.99 /year”, “Just $9.99/month, billed annually”, “7-Day Free Trial”; Monthly “$19.99 /month”; “Get Up to 30% Off” for military, first responders, medical professionals, teachers and students. Accessed October 5, 2026. https://shred.app/pricing ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰

7. FitnessAI. Homepage — “AI tells you exactly what to lift - sets, reps, weights”; “Workouts in 5–30 minutes that fit your schedule”; “Adapts to any equipment - gym, home, or travel”; “Built on 100M+ training sessions from real lifters”; “Track progress with 3D BodyScan visualization”; “Wearable Integration: Sync your performance automatically for accurate training data with Apple Watch”; “Structured Challenges. Real Stakes. Focused challenges built to drive muscle growth, lean results, and consistency - with rewards on the line”; “Get Started For Free”. Accessed October 5, 2026. https://www.fitnessai.com ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵

8. SensAI. Homepage — “Your AI coach follows along and adjusts the workout mid-session”; “Modify workouts mid-session with natural language”; “Weekly regeneration based on what you actually did and how you recovered”; “HRV and sleep quality inform daily programming and intensity”; Apple Watch: “Guided set-by-set tracking with rest timers, muscle group visuals, and real-time heart rate zones”. Accessed October 5, 2026. https://www.sensai.fit ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶

9. SensAI Help Center. “Connect your wearable to SensAI through Apple Health.” Last updated September 25, 2026 — SensAI reads Apple Health only; “Will Coach see my HRV? Only from Apple Watch. Garmin, Oura, WHOOP, COROS, Polar, and Fitbit do not write HRV to Apple Health”; vendor scores such as Body Battery, Recovery and Readiness “never transfer”; “It syncs roughly the last 30 days of Apple Health workouts”; “Sleep and overnight heart rate from your device shape how hard Coach asks you to push on a given day.” https://www.sensai.fit/help/connect-wearable-to-sensai-apple-health ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵

10. Origami, Inc. “SensAI: Fitness Sensei.” Apple App Store listing (id6738963099) — SensAI Premium $6.99 monthly, $69.99 yearly; “Try free for 7 days. No subscription required to start.”; requires iOS 26.0 and watchOS 26.0; iPhone and Apple Watch; version 1.1.6 (September 30, 2026); 4.6 rating from 36 ratings. Accessed October 5, 2026. https://apps.apple.com/us/app/sensai-fitness-sensei/id6738963099 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²²

11. GlobeNewswire. “FitnessAI Expands to Android, Broadening Access to AI-Driven Workouts.” November 25, 2024 — FitnessAI, owned by Appex Group, Inc. of Boston, “a mobile application studio specializing in building, scaling, and acquiring innovative apps”; Karetha Strand, CEO: “We’re excited to announce the launch of FitnessAI on Android, marking a significant milestone in our mission to bring intelligent strength training to a broader audience”. https://www.globenewswire.com/news-release/2024/11/25/2986845/0/en/FitnessAI-Expands-to-Android-Broadening-Access-to-AI-Driven-Workouts.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

12. Google Play listings checked October 5, 2026: Fitness AI (4.5 from 1.37K reviews, 50K+ downloads) https://play.google.com/store/apps/details?id=com.fitnessai.android ; Zing AI (4.7 from 8.6K reviews, 500K+ downloads) https://play.google.com/store/apps/details?id=coach.zing.fitness ; Planfit (4.7 from 26.7K reviews, 1M+ downloads) https://play.google.com/store/apps/details?id=com.mih.planfit ; SHRED (4.5 from 1.95K reviews, 100K+ downloads) https://play.google.com/store/apps/details?id=app.shred.android ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²²

13. Daniel Fisher. “Zing’s AI Coach Gets an Upgrade [Feature Focus].” Zing Coach fitness library, 2025 — “Simply type commands like ‘Add cardio to my plan,’ and watch your AI workout plan update instantly”; “Your AI fitness coach now supports images, allowing you to upload photos of your workouts for real-time feedback and form correction.” Accessed October 5, 2026. https://www.zing.coach/fitness-library/zing-ai-coach-upgrades ↩ ↩²

14. KED Global. “Korea’s No. 1 fitness app Planfit eyes bigger market beyond home in 2025.” January 2025 — “Planfit recommends personal exercise programs using exercise datasets consisting of about 60 million exercise records. The large language model is the main machine-learning algorithm used to operate the app”; “In early 2024, it launched a ChatGPT-based workout coaching program, or personal AI trainer called Planfit GPT”; CEO Baek Hyeonwoo: “Our goal is to help our members easily maintain their training for longer periods”. Accessed October 5, 2026. https://www.kedglobal.com/korean-startups/newsView/ked202501070008 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

15. Courtney Rehfeldt. “Shred App Launches CoachAI To Bring Next-Gen Personalization to Fitness.” Athletech News, September 29, 2025 — Shred founder and CEO Charlie Hale: “CoachAI represents the evolution from static content to a living intelligence system.” Accessed October 5, 2026. https://athletechnews.com/shred-app-coachai-next-gen-personalization-to-fitness/ ↩ ↩²

16. Orli Cole, Head of Content. “Make the Most Out of Every FitnessAI Workout.” FitnessAI blog, June 27, 2025 — “If you notice a weight that you know will be too light or too heavy for you, change it!” Accessed October 5, 2026. https://www.fitnessai.com/blog/make-the-most-out-of-every-fitnessai-workout ↩

17. Planfit. “About.” — “16M+ workouts logged”; “87M+ exercises logged”; “300M+ sets recorded”; “245,000+ gyms across 150 countries”; “9M+ pieces of equipment mapped”; founded June 2021 by Hyeonwoo Baek. Accessed October 5, 2026. https://planfit.ai/en/about ↩ ↩² ↩³ ↩⁴ ↩⁵

18. Zing. https://www.zing.coach/ returned HTTP 307 to https://partner.zing.coach/, titled “AI Fitness Coaching for Gyms and Apps | ZNG COACH™” — “The engine behind it is built on 7.5M+ real workouts from 850,000+ paying users across 80 countries.” Observed October 5, 2026. https://partner.zing.coach/ ↩ ↩² ↩³

19. Havers T, Masur L, Isenmann E, Geisler S, Zinner C, Sperlich B, Düking P. “Reproducibility and quality of hypertrophy-related training plans generated by GPT-4 and Google Gemini as evaluated by coaching experts.” Biology of Sport, 2025;42(2):289-329. PMID: 40182716. https://pubmed.ncbi.nlm.nih.gov/40182716/ ↩ ↩² ↩³

20. Havers T, Jelonnek C, Masur L, Isenmann E, Sperlich B, Geisler S, Düking P. “A professional assessment of training plans for muscle hypertrophy and maximal strength developed by generative artificial intelligence.” Biology of Sport, 2025;42(4):353-366. PMID: 41048240. https://pubmed.ncbi.nlm.nih.gov/41048240/ ↩ ↩² ↩³ ↩⁴ ↩⁵

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