> ## Content Index > Fetch the complete content index at: https://theseguysknow.io/llms.txt > Use this file to discover other available public pages before exploring further. # When to Add More Weight or Reps at the Gym - URL: https://theseguysknow.io/more-weight-or-more-reps/ - Published: 2026-10-07T07:13:08.000Z - Updated: 2026-10-07T07:13:08.000Z - Description: Should 16 kg (35.3 lb) curls become 20 kg (44.1 lb) next week? We explain how to add reps, when to try a heavier dumbbell and what to do when your gym's weight jumps are too large. - Author: Kendrick Hale - Tags: Things to Learn, Health & Fitness You curl 16 kg (35.3 lb) twice a week, and someone tells you to keep increasing the weight. That still leaves the useful question unanswered: should you pick up 18 kg (39.7 lb), jump to 20 kg (44.1 lb), or stay at 16 kg (35.3 lb) and do another rep? ## Quick Answer For muscle-building curls, we would start with three working sets of 8–12 reps, keeping the same weight while you build towards 12 in every set. If your results are 10, nine and eight reps, a useful target next time is 10, nine and nine, giving you one extra rep across the exercise. Once you can repeat 12 in all three sets over two sessions, with controlled movement and a couple of good reps still possible, try a small weight increase. At 16 kg (35.3 lb), that could mean 17 kg (37.5 lb) if your equipment allows it, or testing 18 kg (39.7 lb) if that is the next available dumbbell. Going straight to 20 kg (44.1 lb) is a 25% increase, so training twice a week certainly doesn't make that your automatic target for the following week. All dumbbell weights below mean the weight in each hand, and 10 / 9 / 8 means ten reps in the first set, nine in the second and eight in the third, for each arm. | Your last curl workout | What to do next time | | ------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------- | | 16 kg (35.3 lb) for 10 / 9 / 8 reps | Keep 16 kg (35.3 lb) and aim for 10 / 9 / 9 | | 16 kg (35.3 lb) for 12 / 12 / 12, achieved once | Repeat 16 kg (35.3 lb) to check you can do it again with the same technique | | 16 kg (35.3 lb) for 12 / 12 / 12 over two sessions, with a couple of reps left | Try 17 kg (37.5 lb) if available; otherwise test 18 kg (39.7 lb) and check whether you can stay within 8–12 reps | | The heavier weight gives you fewer than eight good reps | Return to 16 kg (35.3 lb), or use equipment that allows a smaller increase | ## How Many Reps Should You Add? Aim for one extra rep across your working sets at the next workout. You don't have to add one to every set, and you don't have to force an extra rep when the only way to finish it is to swing the weight or shorten the movement. If you curled 16 kg (35.3 lb) for 10 / 9 / 8, you completed 27 reps per arm across three sets. Getting 10 / 9 / 9 next time gives you 28, while 10 / 10 / 9 gives you 29; either is useful progress when the movement and effort stay similar. If you're stronger than that target suggests, you can add more than one rep, provided you keep the sets controlled and challenging. Suppose you train curls on Monday and Thursday. Here is how the method could look, with the later rows showing milestones you might reach after several more sessions. | Curl session | Dumbbell weight, per hand | Reps in the three working sets | | ------------------------------ | --------------------------------------------- | ------------------------------------------ | | Monday | 16 kg (35.3 lb) | 10 / 9 / 8 | | Thursday | 16 kg (35.3 lb) | 10 / 10 / 8 | | Following Monday | 16 kg (35.3 lb) | 11 / 10 / 8 | | A later session | 16 kg (35.3 lb) | 12 / 12 / 12 | | Following curl session | 16 kg (35.3 lb) | 12 / 12 / 12 again | | First session with more weight | 17 kg (37.5 lb), or a test of 18 kg (39.7 lb) | Aim to remain within 8–12 reps in each set | This is an example of how to make the decision, not a promise about how quickly your reps will increase. Training twice a week gives you two opportunities to check your performance; you could spend several weeks at 16 kg (35.3 lb) while the reps improve. Count your warm-up separately, and start with roughly two minutes of rest between working sets so you're giving yourself a reasonable chance to repeat the exercise. Take longer if you need it, and keep the rest similar from session to session when comparing results. If you alternate arms, ten reps means ten on the left and ten on the right, not five each. ## How Much Weight Should You Add? For your 16 kg (35.3 lb) curls, adding 1 kg (2.2 lb) per dumbbell is a useful first option when your equipment allows it. Adding 2 kg (4.4 lb) is a bigger step that you may need to build towards, while adding 4 kg (8.8 lb) would be a substantial jump for that exercise. | Change, per dumbbell | Weight added | Percentage increase | | --------------------------------- | ------------- | ------------------- | | 16 kg (35.3 lb) → 17 kg (37.5 lb) | 1 kg (2.2 lb) | 6.3% | | 16 kg (35.3 lb) → 18 kg (39.7 lb) | 2 kg (4.4 lb) | 12.5% | | 16 kg (35.3 lb) → 20 kg (44.1 lb) | 4 kg (8.8 lb) | 25% | The American College of Sports Medicine's 2009 guidance suggested [weight increases of roughly 2–10%](https://pubmed.ncbi.nlm.nih.gov/19204579/?ref=theseguysknow.io) after someone could exceed their rep target by one or two reps over two consecutive sessions. At 16 kg (35.3 lb), a 10% increase is only 1.6 kg (3.5 lb), which explains why the next dumbbell can feel much heavier than the advice makes it sound. Some metric racks go up in [2 kg (4.4 lb) steps, as Hammer Strength's urethane sets do](https://shop-uk.lifefitness.com/products/hammer-strength-4-sided-urethane-dumbbells?ref=theseguysknow.io), giving you 16 kg (35.3 lb), 18 kg (39.7 lb) and 20 kg (44.1 lb). Once you have reached the rep target twice, try the 18 kg (39.7 lb) pair after warming up and see whether you can perform at least eight controlled reps in each working set. A drop from 12 to nine reps is expected; needing to rock backwards to get the dumbbell up means that weight is too much for the curl we're describing. If 18 kg (39.7 lb) is too heavy, return to 16 kg (35.3 lb) and extend your target to 8–15 reps, building towards 15 in each set before trying the increase again. That gives you a clear next step while you work towards the rack's larger jump, although it doesn't guarantee that 18 kg (39.7 lb) will be manageable on a particular date. Equipment with smaller increments is another option, especially if the rack skips straight from 30 to 20 kg (44.1 lb). The same percentage looks different on a heavier barbell exercise. Once you're ready to increase, 50 kg (110.2 lb) to 52.5 kg (115.7 lb) is 5%, and 100 kg (220.5 lb) to 105 kg (231.5 lb) is also 5%; those are examples of modest changes that you can assess against your exercise's rep target. They aren't amounts you must add every week, and a smaller available increase is fine. ## What the Gym Weight Labels Mean Check whether the label says KG for kilograms or LB/LBS for pounds before you record the number. A dumbbell marked 16 KG weighs 16 kg (35.3 lb), whereas one marked 16 LB weighs about 7.3 kg (16 lb), so the same printed number can mean very different weights. A dumbbell's label normally gives the weight of that individual dumbbell. Moving from two 16 kg (35.3 lb) dumbbells to two 18 kg (39.7 lb) dumbbells adds 2 kg (4.4 lb) to each hand, or 4 kg (8.8 lb) across the pair, but your record should still read 18 kg (39.7 lb) per hand. With a barbell, record the bar plus all the plates as one total. Adding a [1.25 kg (2.8 lb) plate](https://www.roguefitness.com/rogue-calibrated-kg-steel-plates?ref=theseguysknow.io) to each side adds 2.5 kg (5.5 lb) altogether, while a 2.5 kg (5.5 lb) plate on each side adds 5 kg (11.0 lb); check the bar's own weight, particularly with curl bars, because it is part of what you're lifting. On a machine, check its unit label and available increments instead of assuming the next pin position adds 2 kg (4.4 lb). Keep a separate record for each machine and for your dumbbell curls, so changing equipment doesn't get mistaken for an increase in strength. ## Why Adding Reps Can Build Muscle For building muscle, the sets need to be challenging enough for the weight you're using. If you finish ten curls knowing another two or three controlled reps were possible, that is a useful starting level of effort; if you could easily have done another fifteen, stopping at ten leaves a lot of room to make the set more demanding. The [2026 ACSM position stand discusses leaving two or three reps available](https://pmc.ncbi.nlm.nih.gov/articles/PMC12965823/?ref=theseguysknow.io) as one way to reach sufficient effort, while explaining that you don't have to reach failure and that an exact best stopping point has not been established. That is why our example asks you to keep a couple of reps available instead of turning every set into an attempt you can't finish. An [eight-week trial involving 43 trained participants](https://pubmed.ncbi.nlm.nih.gov/36199287/?ref=theseguysknow.io), coauthored by Mike Israetel and Brad Schoenfeld, compared progressing through more weight with progressing through more repetitions. Both approaches worked over the study period, with broadly similar results across the measurements. The trial involved lower-body exercises, so it supports rep progression as an option without establishing the ideal biceps routine. [Arnold's Pump Club makes a useful point about lighter weights](https://arnoldspumpclub.com/blogs/newsletter/myth-of-the-week?ref=theseguysknow.io): they can build muscle, but endlessly repeating an easy weight isn't enough. That fits the decision here, because staying at 16 kg (35.3 lb) can make sense while your challenging sets improve, and it stops making sense as a growth strategy if you settle for the same effortless ten reps indefinitely. A hundred reps also doesn't automatically beat ten because the multiplication is bigger. Using 10 kg (22.0 lb) for 100 reps gives a larger load-times-reps total than using 50 kg (110.2 lb) for ten, yet that multiplication doesn't measure muscle growth. A review found [similar growth across different loads, with heavier loading better for maximal strength](https://pmc.ncbi.nlm.nih.gov/articles/PMC8126497/?ref=theseguysknow.io), but its included studies used sets taken to failure. Those results give you no reason to assume an easy set becomes better simply by lasting longer. ## What If You Can't Add Any Reps? If the extra rep isn't there, keep the same weight and try again at the next session. Check whether you rested enough and performed the same movement before treating one disappointing workout as a reason to change everything. If several sessions pass without improvement, review the exercise and your recovery. You're comparing like with like only if the rest, movement and place in the workout are similar, and adding more weight won't fix a curl you already struggle to control. Sharp or joint pain is a reason to stop and address the problem; soreness also isn't a requirement for progress, as we explain in our [gym myths article](https://theseguysknow.io/common-gym-myths/). If performance is falling across several exercises and you feel worn out, look at your training workload, sleep and food before piling on more sets. Our [beginner muscle-building guide](https://theseguysknow.io/how-to-gain-muscle-for-beginners/) covers how those parts fit together. ## Final Verdict If you're curling 16 kg (35.3 lb) twice a week, start by aiming for one extra good rep across your sets at the next session. Once you can repeat the top of your range across all three sets, try the smallest available increase and judge it by how well you can still curl the weight. For this example, 17 kg (37.5 lb) is the smaller step, 18 kg (39.7 lb) is a larger jump to test, and 20 kg (44.1 lb) should certainly not become next week's target just because a week has passed. If the next dumbbell is too heavy, keep 16 kg (35.3 lb) and build towards a higher rep target instead of forcing the movement. --- ## FAQ ### Should I Add 4 kg (8.8 lb) After One Week? That shouldn't be your default, because it adds a quarter to the weight in each hand. Use your rep performance to decide when to increase, and try a smaller step when your equipment allows it. ### Do I Have to Add One Rep to Every Set? You can aim for one extra rep across the whole exercise, so 10 / 9 / 8 becomes 10 / 9 / 9\. Add more if you can keep the same movement and level of effort, but don't force the target through worse technique. ### What If the Next Dumbbell Is 20 kg (44.1 lb)? Keep progressing with the 16 kg (35.3 lb) pair within a higher rep range, such as 8–15, or use curl equipment with smaller increments. Reaching 15 reps doesn't guarantee you're ready for a 25% weight increase, so test cautiously and return to the lighter option if you can't control it. --- #### Sources ****Training research and guidance** - [ACSM: Progression models in resistance training, 2009](https://pubmed.ncbi.nlm.nih.gov/19204579/?ref=theseguysknow.io) - [ACSM: Resistance-training position stand, 2026](https://pmc.ncbi.nlm.nih.gov/articles/PMC12965823/?ref=theseguysknow.io) - [Plotkin et al.: Load progression versus repetition progression, 2022](https://pubmed.ncbi.nlm.nih.gov/36199287/?ref=theseguysknow.io) - [Lopez et al.: Resistance-training loads, muscle growth and strength, 2021](https://pmc.ncbi.nlm.nih.gov/articles/PMC8126497/?ref=theseguysknow.io) - [Arnold's Pump Club: Heavier weights and higher repetitions](https://arnoldspumpclub.com/blogs/newsletter/myth-of-the-week?ref=theseguysknow.io) ****Equipment specifications** - [Hammer Strength: Urethane dumbbell sets in 2 kg (4.4 lb) increments](https://shop-uk.lifefitness.com/products/hammer-strength-4-sided-urethane-dumbbells?ref=theseguysknow.io) - [Rogue: Metric plates, including 1.25 kg (2.8 lb) and 2.5 kg (5.5 lb)](https://www.roguefitness.com/rogue-calibrated-kg-steel-plates?ref=theseguysknow.io) ****Related TGK articles** - [Common Gym Myths](https://theseguysknow.io/common-gym-myths/) - [How to Gain Muscle for Beginners: Training, Food and Rest](https://theseguysknow.io/how-to-gain-muscle-for-beginners/)