The benefits of a personal trainer that hold up in practice are five, and all of them can be measured: you train more consistently, your loads rise on a written plan instead of by feel, your effort is calibrated (untrained lifters in one study underestimated their reps in reserve by four to five), your technique is built before it’s loaded, and your baseline tests are repeated. At VAULT Training, Brandschenkestrasse 150, 8002 Zürich (Enge), the first eight sessions are built around those five. What a trainer can’t do is eat, walk or sleep for you, and that’s what decides body composition.
Our old version of this post listed ten benefits. After fifteen years and more than 1,000 clients through the same method, I’d cut it to these five.
The benefits of a personal trainer, in the order they matter
1. You keep showing up
When I rank the variables of a program, adherence comes first, then progressive overload, then volume, then proximity to failure. Someone who sits nine hours a day, comes twice a week and follows a slightly boring program for a year beats anyone who does a textbook program for five weeks and stops. I’ve seen both often enough to stop arguing about it.
That’s why the most valuable thing a VAULT coach does happens in the last minute of the session: the next one is booked before you leave. Some people find that pushy. I do it anyway, because the client who “will email later” is the one I lose.
An 8-week randomised trial in 36 trained lifters found that supervised training produced larger gains in muscle thickness and squat strength than the same program done alone, with better adherence (Coleman et al., 2023). A meta-analysis of 12 studies found a moderate effect of supervision on strength and almost none on body composition (Fisher et al., 2022).
2. Progressive overload that’s written down
Walk through any commercial gym and you’ll see people who have trained for three years and lift what they lifted in year one. They change exercises every week, so there’s nothing to compare, and nothing to compare means nothing to progress. Of all the advice handed out on gym floors, “keep it varied” is the one I like least.
At VAULT a block is 8 to 12 weeks with the same exercises. I prefer that even though it’s less entertaining than a new workout every visit, because it’s the only way a number can go up. The default is double progression: a rep range of 8 to 12, one more rep per session, and when every set hits 12 we add 2.5 to 5 kg on upper-body lifts or 5 to 10 kg on lower-body lifts and go back to 8.
It has to be on paper because you train with VAULT, not with one person, and you’ll see more than one coach over a year. Whoever walks in on Thursday needs to know you did 3×11 at 60 kg on Monday and that your right knee complained at the bottom of the split squat. “Good session” in the notes helps nobody, and I’ve read a lot of them.
3. Your “two reps left” is probably four
We prescribe effort in reps in reserve (RIR): the clean reps you could still do when the set ends, mostly RIR 1 to 3. People misjudge it, and beginners misjudge it most; I ask the question after every set and I’ve learned to add two. In a study of 141 lifters, the least experienced underestimated how many reps they had left by about 4 to 5; the most experienced by 1 to 2 (Steele et al., 2017). A meta-analysis of 12 studies and 414 participants put the average error nearer one rep and found no clear effect of experience, but the direction held: people underpredict, and they get more accurate close to failure and in sets of 12 reps or fewer (Halperin et al., 2022).
That matches what I see on the floor.
So I don’t calculate your starting weight. We find it together, in the first session: you begin conservative, I ask after every set, “How many more could you have done?”, and the weight moves up or down until the answer is “one or two.” No 1RM test, and never on day one with an exercise you haven’t learned yet. Once in a while we take you to real failure on a machine so you learn what a 2 feels like; until then I assume your 2 is a 4.
4. Bracing and the hip hinge, in the first eight sessions
Two things gate every loaded movement: a rigid trunk (bracing) and bending from the hips with a neutral spine (the hip hinge). Both are taught in your first eight sessions, before I care much about how much you lift.
The hinge is hard for people who sit all day: short hip flexors, glutes that don’t fire, and a habit of bending from the lower back instead. So we build it in steps. Tilt the pelvis forward and back. Hinge on the knees with a band. A dowel along the spine with three points of contact (head, upper back, sacrum). Reach back to touch a wall. Only then a kettlebell. Bracing has its own ladder, from diaphragmatic breathing on the floor to dead bugs, planks and Pallof presses.
None of this is “mobility work”. It’s what lets us load a deadlift later without guessing.
5. A test that isn’t repeated is paperwork
Your first one or two sessions include baseline tests: standing posture, air squats in 30 seconds, grip strength left and right on a dynamometer, maximum push-ups, a 15-calorie row and bike, and your hours of sleep. Yes, sleep is a test; on day one I’d rather know your hours than your squat.
I repeat them at the end of the block. A scale tells you that you’re 2.5 kg lighter; it can’t tell you whether that was fat, muscle or water, which is the question you actually had.
What a personal trainer can’t do for you
A coach controls about three hours of your week. The other 165 are yours, and that’s where the meta-analysis above bites: supervision moves strength, and on its own it barely moves body composition. That’s decided by what you eat, how much you walk (we prescribe 10,000 to 12,000 steps a day, starting from wherever you are) and how much you sleep. We set targets, hand you a monthly consistency sheet with five daily tasks and ask about it every session. I can’t do it for you.
We also don’t diagnose or treat anything. If your knee hurts, a VAULT coach changes the exercise and the range, and sends you to a doctor or physio when that’s the right call. Training supports back and joint health; it isn’t medical care, and I’d rather lose a session to a physio referral than guess.
The same line applies to food. Our old post promised “nutritional guidance” from your trainer; I’d word that differently now. What a coach here gives is sports-nutrition education: roughly how much protein per kilo, why the steps matter, why the scale lies. Individual plans are a separate service, nutrition coaching with Roberta Burla (MAS ETH Nutrition and Health), and anything touching a medical condition goes to a doctor first.
When you don’t need one
If you already keep a training log, add weight or reps most weeks, train three times a week without pain and repeat a few tests every quarter, you’re doing what I would make you do. A single session to check your hinge and your loads may be worth more than a pack.
If two of those four aren’t true, that’s where I’d put the money.
Frequently asked questions
Is a personal trainer worth it?
It’s worth it when what’s missing is consistency, a written progression or technique, because those are what supervision changes. It isn’t a substitute for eating, walking and sleeping well, which decide body composition. At VAULT the first two sessions are an assessment, so within a week you know which of those two cases you are.
Is a personal trainer once a week enough?
Once a week is enough if it’s the frequency you’ll sustain, but at one session a week your weekly volume per muscle group sits near maintenance, so progress is slower. Our 16×3×12 method (16 quality sets, three sessions a week, twelve weeks) stretches to 18 weeks at two sessions a week and 36 weeks at one. A second, self-directed session from your written plan changes that.
What does a personal trainer actually do in a session?
At VAULT a session is 60 minutes: a warm-up specific to what you’ll lift, about five minutes of power work, 40 to 45 minutes of strength in paired exercises with a third slot for your weak point or core, and an optional two to three minutes of conditioning. Every set is logged with load, reps and RIR, with a note for the next coach. The last minute books your next session.
How much does a personal trainer cost in Zürich?
At VAULT a 60-minute 1-to-1 session costs CHF 130 to 195 depending on whether you buy a pack or a monthly plan, and monthly plans start at CHF 611 for once a week; every plan includes the assessment and body composition measurements. The full breakdown is on our pricing page and in our post on what personal trainer costs.
Come and find your starting weight
Book a free trial session and we’ll teach you the hinge, calibrate your starting weights together with you, and you’ll leave with numbers of your own to beat: book a free trial.