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Is a personal trainer worth it?

By Stelvo Team · · 6 min read

Short answer: for results per week, yes — the only randomised trial run inside a commercial gym found members who trained under a trainer's programme gained 1.3 kg of lean mass in 12 weeks while self-directed members gained none, and improved chest-press strength 42% versus 19%. Whether that is worth the price depends on what the trainer changes: in the research, the gains come from progressive loading, real intensity and showing up — which is also why 22.6% of US gym members use one, and why an app or a partner can capture part of the effect.

What percentage of gym members use a personal trainer?

Nearly one in four. In 2024, 22.6% of US fitness facility members worked with a personal trainer and 32.3% took part in small-group training; 7.3 million women used personal training, up 15.9% in a year, and the average client did 21 sessions a year, down from 28 in 2019 (Health & Fitness Association, 2025). The supply side is large and growing: the US had 388,400 fitness trainer and instructor jobs in 2025, projected to grow 7% by 2035 (Bureau of Labor Statistics).

Do people with a personal trainer get better results?

Yes, in both controlled comparisons. Men aged 30–44 who were members of one Southern California club were randomised to 12 weeks of training three days a week either with a trainer administering a periodised programme or on their own. The trainer group gained 1.3 kg of lean body mass (DXA) versus no change, improved chest-press strength 42% versus 19%, peak leg power 6% versus 0.6% and VO2max 7% versus a 0.3% decline; leg-press strength rose 38% versus 25% (Storer et al., Journal of Strength and Conditioning Research, 2014).

An earlier trial isolated the mechanism: 20 moderately trained men followed identical 12-week periodised programmes, one group directly supervised by a trainer and one not. The supervised group raised its training loads faster — significantly heavier sets from week seven on for the squat and week three for the bench press — and finished with significantly greater one-rep maxima in both lifts (Mazzetti et al., Medicine & Science in Sports & Exercise, 2000). Same plan; the trainer's job was making sure the weight went up.

Outcome (12 weeks) With trainer Self-directed Source
Lean body mass +1.3 kg No change Storer et al., 2014
Chest-press strength +42% +19% Storer et al., 2014
Leg-press strength +38% +25% Storer et al., 2014
Peak leg power +6% +0.6% Storer et al., 2014
VO2max +7% −0.3% Storer et al., 2014
Training load progression Faster, heavier Slower Mazzetti et al., 2000

What exactly are you paying for?

Three things the trials point at, in order of importance:

  1. Progressive load. Untrained lifters under-load themselves. The supervised group in Mazzetti's study used significantly heavier sets in most weeks of the programme; that difference, not a secret exercise, produced the strength gap.
  2. Intensity that is real. The strongest twice-a-week results in the literature — 2.9% more spine bone density in eight months — came from supervised sessions at five sets of five above 85% of one-rep max (Watson et al., Journal of Bone and Mineral Research, 2018).
  3. Showing up. New gym members needed at least four sessions a week for six weeks to form a habit (Kaushal & Rhodes, Journal of Behavioral Medicine, 2015), and 63% of new members in the largest attrition study had quit before the third month (Sperandei et al., Journal of Science and Medicine in Sport, 2016). A booked session is the oldest accountability device there is.

When is a personal trainer not worth it?

  • If you already progress your lifts. The supervised advantage in both trials came from load and intensity; a lifter who tracks and adds weight is already doing the trainer's core job.
  • If the sessions replace, rather than build, your own habit. 21 sessions a year — the 2024 average — is one every two and a half weeks, well under the frequency that forms a habit.
  • If the budget only stretches to a few sessions. Front-load them: technique and a progression plan in the first six weeks capture most of the value.

Are there cheaper ways to get the same effect?

Partly. Self-monitoring — logging loads and reps — was the single technique that most separated effective activity programmes from ineffective ones across 122 evaluations, and pairing it with planning raised the effect from 0.26 to 0.42 (Michie et al., Health Psychology, 2009). A training partner whose result depends on yours doubled how long people kept working (21.9 versus 10.6 minutes) (Irwin et al., Annals of Behavioral Medicine, 2012). Neither replaces a coach's eye on your form; both replicate the "make the weight go up and show up" half of the effect.

How Stelvo handles this

Stelvo does the load-progression job automatically: it suggests working weights from your previous sessions, logs every set, and lets you ask the coach mid-workout to swap an exercise or check whether to push for another rep. It remembers your injuries, schedule and goals between sessions the way a trainer would — for the price of an app rather than 21 sessions a year.

FAQ

How many personal training sessions do you need?

The trials that showed the gap ran 12 weeks at three sessions a week; the average US client does 21 sessions a year. If money is limited, concentrate sessions in the first six to twelve weeks when technique and progression are being set.

Is a personal trainer worth it for beginners?

Beginners are where the measured gap is largest, because under-loading and quitting early are beginner problems: the trainer group in Storer's trial gained lean mass and strength that the self-directed group did not.

Is a personal trainer worth it for weight loss?

The trials measured lean mass and strength rather than weight; the trainer group gained muscle, which is the part of "weight loss" most people actually want.

Sources

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