Can fitness apps match the expertise of a personal trainer?

Jenny Wiener’s early struggle

Four years ago, Jenny Wiener found herself in a fitness slump that left her feeling frustrated and stuck. Jenny Wiener wanted to improve both physical health and mental wellbeing, but the workouts that Jenny Wiener attempted lacked the intensity needed for real progress because Jenny Wiener did not have a structured training programme to follow.

When Jenny Wiener visited the gym, Jenny Wiener often chose what Jenny Wiener called “easy” options, such as jogging on a treadmill, to avoid more daunting exercises that might have pushed Jenny Wiener’s limits.

The prospect of hiring a personal trainer to provide that push was out of reach for Jenny Wiener because the typical cost for a personal trainer session starts at £30 per hour, a price point that Jenny Wiener found prohibitive.

Discovery of the Freeletics app

Jenny Wiener, a 32‑year‑old events manager living in St Albans, discovered the Freeletics app while searching for an affordable alternative to a human coach. To begin using the Freeletics app, Jenny Wiener entered personal data about previous training experiences, preferred exercise styles, and specific fitness goals. The Freeletics app then generated a virtual coach that used the supplied information to suggest a personalised training regime.

At the conclusion of each workout, the Freeletics app prompted Jenny Wiener to provide feedback regarding the suitability and difficulty of that session. The Freeletics app’s artificial intelligence (AI) system collected Jenny Wiener’s responses together with feedback from the app’s broader community of more than 53 million users worldwide. The AI system used this aggregated data to continuously adjust future training sessions for Jenny Wiener, tailoring the difficulty and style to match evolving performance.

“The AI aspect is one of the main things that got me interested,” Jenny Wiener explained. “I was going to the gym every day before, but seeing zero results.”

“When I found Freeletics, I was like ‘OMG it’s a PT in my pocket, my gym buddy’,” Jenny Wiener added, emphasising the sense of companionship that the digital coach provided.

Jenny Wiener finds the workouts exciting because no two sessions are ever identical, a variety that Jenny Wiener credits with maintaining motivation and preventing boredom. As a result of following the Freeletics app’s plan, Jenny Wiener lost four stone, a transformation that Jenny Wiener attributes largely to the consistent, data‑driven adjustments made by the AI system.

The Freeletics app offers a digital personal‑trainer service called “The Coach,” available from £1.78 per week. Kornelius Brunner, chief product and technology officer at Freeletics, explains that the AI system “gets smarter and better” as users provide more feedback, allowing the platform to refine recommendations for each individual.

Psychological perspective from Anthony Papathomas

Anthony Papathomas, a sports and fitness psychologist and senior lecturer at Loughborough University’s National Centre for Sport and Exercise Medicine, argues that AI‑driven apps cannot fully replace the nuanced support offered by a human personal trainer. Anthony Papathomas notes that an interpersonal relationship creates an increased sensitivity to personal needs, something that a digital platform may struggle to replicate.

“If you don’t fancy the session, or if you’re not in a mood, which is often the case, particularly in exercise behaviour change, then I’m not sure the kind of alert you get on your phone necessarily takes into consideration that we are human beings with competing interests outside of our health and fitness,” Anthony Papathomas said.

Anthony Papathomas further points out that a human trainer is more likely to empathise with emotional states, and that enjoyment is a key factor for sustainable exercise habits.

Tom Bourlet’s experience with FitnessAI

Tom Bourlet, a marketing consultant based in Brighton, recalls a period when exercising felt enjoyable before a relationship shift caused motivation to dip. In January of this year, Tom Bourlet and a partner received a wedding invitation, prompting both individuals to set a weight‑loss target to look their best on the big day.

To meet this goal, Tom Bourlet discovered the FitnessAI app, which employs a data‑driven methodology similar to the Freeletics app. The FitnessAI app mines user data to improve and personalise workouts for each individual.

“I often utilise data in my work, and find it incredibly useful to ensure you’re making continuous progress, therefore the entire concept appealed to me,” Tom Bourlet explained.

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Tom Bourlet identified a common pitfall: repeating the same repetitions or weights each week without progressive overload. The FitnessAI app helped Tom Bourlet set precise weekly targets, preventing stagnation.

Previously, Tom Bourlet took long rests of two to three minutes between sets. The FitnessAI app’s AI system calculated exact rest intervals tailored to each specific exercise, weight lifted, and performance level, keeping Tom Bourlet on‑track throughout the session.

Following the structured plan, Tom Bourlet achieved the weight‑loss target of dropping three stone (approximately 19 kg) nearly a month ahead of schedule.

Jake Mor, founder of FitnessAI, claims that the mathematical backbone of the AI system makes the platform superior to a human trainer in terms of precision. “FitnessAI does tons of math behind the scenes to figure out what your workout plan should look like,” Jake Mor said. “While trainers are great motivators, they are not math professionals.”

Counterpoint from personal trainer Aimee Victoria Long

Aimee Victoria Long, a personal trainer based in London, disaCrickxos with the notion that an app can fully replace human expertise. Aimee Victoria Long acknowledges that personal trainers command a higher price, but emphasises the value of one‑to‑one sessions where the trainer can assess an individual’s form directly, ensuring exercises are performed safely and reducing the risk of injury—an element that Aimee Victoria Long says is difficult to guarantee through an app.

Aimee Victoria Long also stresses the importance of understanding both physical and mental health. “I can get to know not only their physical health, but also their mental health, because sometimes people are training all the time, and it might not be good for their mental health. And that’s not going to be shown or picked up on an app,” Aimee Victoria Long explained.

Despite Aimee Victoria Long’s reservations, there are scenarios where an app can ask questions that a human trainer might find uncomfortable to pose.

Jennis: A hormone‑aware approach

The Jennis app, created by British Olympic champion Jessica Ennis‑Hill, incorporates data about menstrual cycles to personalise workout recommendations for female users. The Jennis app requests information from female users regarding their menstrual phase, using the data to adapt the intensity and type of workouts each day.

Jessica Ennis‑Hill explains, “The daily conversations we have with each woman mean that we regularly update recommendations, so that you’re always getting sessions most suited to your hormonal profile.”

Jessica Ennis‑Hill adds that this approach helps users perform exercises that align with their bodies’ physiological state, leading to greater training gains.

Rachel Carey, a former British soldier now living in the United Kingdom, praises the Jennis app for its cycle‑mapping capabilities. After ovulation, Rachel Carey receives strength‑focused workouts, whereas during the first fourteen days of the menstrual cycle, Rachel Carey receives higher‑intensity sessions.

“The cycle‑mapping recommendations for the workouts are so much more appropriate for physiologically what’s going on for me,” Rachel Carey said.

Weighing the evidence

Across the testimonies presented, a clear pattern emerges: AI‑driven fitness apps like Freeletics, FitnessAI, and Jennis provide highly personalised, data‑rich training plans that adapt over time. The AI algorithms harness feedback from millions of users, as well as individual input, to fine‑tune intensity, rest intervals, and exercise selection.

At the same time, experts such as Anthony Papathomas and Aimee Victoria Long highlight the irreplaceable value of human empathy, real‑time form correction, and holistic health monitoring that a personal trainer can deliver.

Jenny Wiener’s four‑stone loss, Tom Bourlet’s three‑stone reduction, and Rachel Carey’s hormonally aligned workouts illustrate the tangible benefits that a well‑designed app can achieve when users commit fully to the programme. Yet, the risk of neglecting form, mental‑health considerations, and the nuanced motivation that a human trainer offers remains a noteworthy caveat.

Ultimately, the decision to rely on a digital platform versus a traditional personal trainer hinges on individual priorities: cost‑effectiveness and data‑driven precision on one side, and personalised human interaction, immediate feedback, and mental‑health awareness on the other.