The program says “dumbbell row, 10 repetitions.” The rack runs from 2 kg to 40 kg. Nothing on the page tells you which pair belongs in your hands.
Your first working weight is something to establish with a controlled trial, then refine. A body-weight chart or another person's dumbbells cannot make that decision for every exercise. Start light enough to learn the movement, work toward the planned repetitions, and record what happened.
The aim of the first session is to leave with a repeatable starting point. You do not need to discover the heaviest weight you can possibly move.
Decide what the set is supposed to do
Choose the exercise and rep target before choosing the weight. Ten controlled repetitions of a row are a different task from three heavy repetitions of a squat or a long set of lateral raises.
For a general introduction, Mayo Clinic's technique guidance suggests beginning with a weight you can lift comfortably for 12 to 15 repetitions. That is a practical starting approach, not a requirement that every program use that range.
If you are following a suitable beginner program, use its target. If an exercise is unfamiliar, get help with its setup and movement before adding a challenging load. Our beginner gym guide covers the broader first-session decisions.
Use a light trial set
Here is a conservative way to find an initial working weight. Treat it as a method for learning, not a test of your limit.
- Set up the exercise. Adjust the seat, bench, cable, or stance. Know how to start and finish the movement safely.
- Rehearse with light resistance. Use an easier version or the lightest practical load while learning. A standard bar can already be too heavy for some movements and beginners.
- Perform the planned repetitions under control. Keep the intended range of motion and avoid adding momentum to finish the set.
- Assess the final repetitions. Could you have done several more with the same technique, or were you already changing the movement to continue?
- Rest before another attempt. If the set was clearly easy, try a small increase. If technique broke down or you missed the target, reduce the load.
You do not have to keep adding until you fail. After a small number of trials, choose a manageable weight and use the next session to refine it. Endless test sets make fatigue part of the decision and can obscure what you could do when fresh.
Use technique as part of the answer
A repetition count alone leaves out the movement. If the final repetitions require swinging the torso, shortening the range, or losing the position you were taught, the weight may be too demanding for the task.
The comparison should be between similar repetitions. Ten controlled rows today and ten heaves next week are different performances, even if the second dumbbell is heavier.
This is why asking a qualified trainer to check a new exercise can be more useful than asking for a number in kilograms. The person watching can evaluate the setup and execution that a generic weight table cannot see.
Stop an exercise that causes pain, as Mayo Clinic advises, and get appropriate guidance if it persists. Do not use pain as a sign that you have finally found an effective weight.
Leave some room before failure
You may hear “reps in reserve,” often shortened to RIR. It means your estimate of how many more repetitions you could complete with acceptable technique. Our RIR and RPE guide explains the distinction in more detail.
For a first session, leaving several good repetitions available is a reasonable way to avoid turning every unfamiliar exercise into a maximum-effort attempt. Your estimate will be imperfect while you learn. Record it as an estimate rather than a precise measurement.
The ACSM's 2026 resistance-training guidance emphasizes tailoring training to the person and goal. Its review did not find that reaching momentary muscle failure consistently improved outcomes for the average healthy adult. You can establish a useful starting load without proving that another repetition is impossible.
An example of finding a working weight
Suppose your plan calls for a machine row for 10 repetitions. The following numbers are illustrative, not suggested starting weights:
| Trial | What happened | Decision |
|---|---|---|
| 15 kg for 10 reps | Smooth, clearly easy | Rest, then try the next small increase |
| 20 kg for 10 reps | Controlled, some effort, several reps probably available | Use this as the initial working weight |
| A later set at 20 kg | Technique starts changing at rep 8 | Stop the set; review rest, fatigue, and whether to reduce the next set |
The later set does not erase the first one. It tells you that the whole session matters, including rest and how much work came before. Do not force ten repetitions at any cost merely because the first set reached ten.
Write down the machine and seat setting as well as the displayed weight. When you return, those details let you repeat the same task more reliably.
Each exercise needs its own starting point
Finding a manageable row weight does not tell you your lateral-raise, squat, or press weight. Establish each separately.
The same caution applies to equipment. A dumbbell label commonly describes one dumbbell; record whether your log uses the weight per hand or the combined pair. For a barbell, include the bar and plates when recording total weight. Check the actual bar rather than assuming every bar weighs the same.
Machine-stack numbers are most useful for comparison on the same machine. Different designs, pulley arrangements, and settings can make two displayed loads feel different. Moving gyms is a reason to recalibrate, not a reason to reproduce a number at any cost.
With body-weight exercises, adjust the version rather than searching for a dumbbell. An incline push-up can be a starting point when floor push-ups are too demanding. The NHS strength guidance includes body-weight and other resistance options and advises gradual progression.
What to do at the next session
Return to the same setup and compare like with like. If the initial weight was controlled and the target remained manageable, repeat it while you learn. There is no rule requiring a heavier weight every time you enter the gym.
When you can meet your program's progression criteria with the intended technique, add the smallest practical increase and reassess. If the next available dumbbell is a large jump, you may need more repetitions within your program's range, different equipment, or advice on a smaller progression. Do not change several variables and then assume the load alone explains the result.
Our progressive-overload guide covers what happens after you have a baseline. Starting-weight selection is the first step; long-term progression is a repeated decision.
Record enough to repeat the set
Keep the log brief: exercise, equipment or setup, load convention, repetitions, and a note about technique or estimated effort. “20 kg, 10 reps, seat 3, controlled” is a more useful baseline than “good workout.”
WinGym Exercises can help you review exercise instructions and log the weights and repetitions you used. The record makes your next session less dependent on memory. It does not replace feedback on technique or an individual rehabilitation plan.
Choose a weight you can control today, then let repeated sessions tell you when to change it. A modest, well-recorded first working weight gives you something solid to build on.
