Where does an app get your starting weight on a new lift?

The short answer

Judged on one thing: what the app does on an exercise it has never seen you train.

• No app can know your first working weight. It has never watched you lift that movement. Anything it shows you came from a formula or from averages of other people.
• SayLift, $4.17 a month (billed $49.99 a year): refuses to guess. The lift is marked BASELINE, the reason reads "New one for me, log a first session and I'll calibrate your weights", and from your second session the normal targets start.
• Fitbod, $79.99 a year: will put a suggested load in front of you, because it generated the session. Useful if you want a number to react to and happy to treat it as a draft.
• Alpha Progression, $79.99 a year: built around planned progression once a lift has a weight and a scheme attached, which makes it strong after the first session rather than at it.
• Hevy ($23.99/yr) and Strong ($29.99/yr): show your last session beside the input field. On a brand new exercise that space is empty, which is honest and leaves the decision with you.
• The practical method, whichever app you use: go clearly lighter than you think, land in the middle of your rep range, and stop about two reps short of failure. One session of that is all an app needs.

What each app puts in an empty weight field

Why no app can honestly fill that field

An app has three possible sources for a weight: your logged history, whatever you typed during setup, and averages taken from other people. On a lift you have never done, the first one is empty. So every number you see on a brand new exercise came from the other two.

Estimating from a lift you already know is the respectable version of this. If your squat top set is 100 kg, a formula can point at a leg press number. To get there it has to assume your limb lengths, your range of motion, how that particular machine's lever arm is built, how fast you were moving, and how close to failure you normally train. Each assumption carries error, and the errors stack. If you do want to work from a known lift, the one-rep max calculator does the arithmetic honestly and labels the result an estimate, which is the right way to use it.

Averages are weaker again. A row that says "intermediate, 80 kg, male" is the middle of a group of people who are not you, training in gyms you have not seen, on equipment that is not yours. It will be roughly right for the population and wrong for you by an amount nobody can predict.

So the better question is what an app should do while it genuinely does not know. A confident number is the worst answer available, because you will believe it. Too heavy and your first session on an unfamiliar movement becomes a grinding set with technique you have not learned yet. Too light and you waste the session, which costs less but still costs something.

The alternative is to say so and ask. That takes one session out of your training block and buys targets that are built from your own lifting rather than from a stranger's. SayLift takes that trade deliberately, and it is the reason this page exists.

How SayLift calibrates, exactly

SayLift's coach returns one action per exercise, per session, computed on the phone from your own logged sets. Six actions exist, and calibrate is the one that fires when there is no usable history for that movement. It advises no weight at all. The reason line reads "New one for me, log a first session and I'll calibrate your weights", and the lift appears on the Today page under BASELINE.

There is a second case that catches people out. You have logged the exercise before, but never with a number against it, which happens easily if you spoke the session and did not say the weight. The lift still has no load to work from, so it calibrates, and the reason changes to "You've done this before but never logged a weight, give me one session with numbers." Nothing is broken. The coach is telling you which part of the record is missing.

It is per exercise, not per session. Bolt one new machine onto an established routine and exactly one lift goes into calibration while the rest keep their normal targets. If every lift in the session is calibrating, which is what a fresh install looks like, the session headline reads "Log your weights to set baselines" instead.

The built-in starter programs are the cleanest proof that this is a design choice rather than a gap. Push / Pull / Legs and Full Body ship with every exercise at 3 sets of 8 to 12 and no weights at all. The app could have filled those fields with plausible numbers. It leaves them empty and calibrates each load from what you actually log, because on day one it has no basis for anything else.

From your second session the ordinary rules take over for that lift. Hit the top of the rep range and it adds 2.5 kg on upper body or 5 kg on lower body (5 lb and 10 lb if you train in pounds). Land mid-range and it holds the weight and asks for one more rep than your lowest working set managed. Fall below the floor of the range and it cuts 7.5 percent and rebuilds. The full set of rules is on workout apps that decide your next working weight.

Bodyweight movements never ask for a weight. Plank, push-up, pull-up, and anything logged as a duration get a hold and track reps or time instead. So the plank at the end of the starter Legs day is not sitting there waiting for a number you were never going to give it.

No history is different from old history. If you trained the lift before and simply stopped, the coach has something to work from, so it restarts you at 10 percent under your last logged weight rather than asking for a baseline. That case is covered on workout apps for getting back to the gym. Calibrate is only for lifts the app has never seen a number for.

The honest limits. Everything above is arithmetic on your own logged sets, not coaching. The coach cannot see your technique on a movement you are learning, which is exactly the situation a new exercise puts you in, so the first session is yours to judge. SayLift is iPhone only (iOS 17+), has no Apple Health sync, does not group supersets, and has no App Store ratings yet because it is new.

How to pick that first weight yourself

One session is all the coach needs, and you only have to get it roughly right. Aim to finish with sets you could describe, not a personal record.

1. 1Start clearly lighter than your instinct says. On a machine you have never used, the empty carriage or the lightest plate that feels like resistance is a fine first set.
2. 2Do a few easy reps and read them. If 8 reps felt like walking, add a plate and go again. Ramp-up sets are warm-ups, and SayLift leaves warm-ups out of its target calculation, so they cannot pull your baseline down. More on that in do warm-up sets count.
3. 3Pick a weight you can take to the middle of your rep range. For a 6 to 12 range that means about 9 reps, not 12 and not 5. The middle leaves the coach room to move you either way.
4. 4Stop about two reps short of failure on a movement you are still learning. You want the pattern, not the maximum, and failure on an unfamiliar lift is where technique falls apart.
5. 5Log the weight and the reps you actually completed, not the ones you planned. The whole value of this session is that the number is real.
6. 6Leave the next session to the coach. It now has a top working weight and a rep count, which is all the rules need.

How to set it up in SayLift

1. 1Install SayLift on iPhone and start the 3-day trial.
2. 2Either build your routine on the Profile tab, paste or dictate a plan you already have, or pick a Training Style in Settings and follow the built-in starter program. The starter programs carry no weights by design.
3. 3Open the Today page. Any exercise with no logged weight sits under BASELINE with its reason line, and if everything is new the headline reads "Log your weights to set baselines".
4. 4Train that exercise using the method above, then log it. Speak the session if you prefer, and say the weight out loud, because a voice log with no number keeps the lift in calibration.
5. 5Check the review screen before you save. Nothing is stored until you confirm it, and this is where a missing weight is easiest to spot.
6. 6Open the Today page before your next session on that lift. The BASELINE marker is gone and a target weight is in its place, with one line explaining it.
7. 7Add a new machine later and only that lift goes back into calibration. Log it once and it joins the rest.

Who SayLift is for

SayLift suits an iPhone lifter who brings their own routine and wants the weights decided from their own logged sets. That applies at any level. A new exercise is a new exercise whether it is your first month in the gym or your tenth year, and a moved gym or a swapped machine puts an experienced lifter in the same empty field as a beginner.

It is the right pick if you would rather be asked for one honest session than handed a number the app cannot stand behind. It is the wrong pick if you want an app to write your first session for you, loads included, with nothing from you first. Fitbod is built for that and will do it well.

If you are new to lifting altogether, the program itself matters more than the tracker, and which weightlifting app to use as a beginner covers choosing one. If the notation on your plan is the unclear part, start with what 3x8 means.

Try SayLift on iPhone. It is $4.17 a month (billed $49.99 a year), $7.99 a month or $3.99 a week after a 3-day trial, and the same subscription covers voice logging, the coach, and 873 exercise guides that work with no signal.