Progressive overload is the core principle of all resistance training: muscle grows and gets stronger only if, over time, it is given more than it is used to. The principle is simple, but few people know what it means in numbers: how much the weight should go up in eight weeks, how hard sets are really done and in which exercises progress shows. In this article we answer with SisuLift's anonymised data: 111,572 logged working sets, 6,362 completed gym sessions and 566 lifters.
What progressive overload means
Overload means the training stimulus exceeds what the body has adapted to. Progressive means the stimulus is increased gradually as the body adapts. Without it the body does what it is already used to, and has no reason to change. Overload can be increased with four levers:
- Load: same exercise, same reps, more kilos. The clearest and easiest to measure.
- Reps: same load, more reps per set. In the study by Plotkin and colleagues (2022, PeerJ) eight weeks of rep progression built as much muscle as load progression.
- Sets: same exercise, more working sets per week. Schoenfeld's meta-analysis (2017) showed a dose-response relationship: more weekly sets, more growth, at least up to about 10-20 sets per muscle group.
- Quality: longer range of motion, more controlled lowering phase, shorter rest. Harder to measure, but real.
In practice the model that works best is double progression: keep the load the same until you hit the top of the rep range in every set (for example three sets with a target of 8-10 reps), then raise the load and start from the bottom of the range. It is also the model SisuLift's weekly progression uses, more on that below.
The dataset: 111,572 sets
All figures are based on sets logged in SisuLift with a load above 0 kg and 1-50 reps, marked as completed and belonging to a gym session that was finished and saved. Warm-up sets, cardio, unfinished sessions, watch-imported activities and history imported from other apps were left out. Individual users are never examined, and every figure is based on at least 20 different users.
The most popular exercises in Finland
The ten most logged exercises cover about a quarter of all sets. The list says two things: the leg press is the most performed exercise in Finland, not the squat, and dumbbells are more common than the barbell for pressing.
The ten most logged exercises by working sets (2 September 2026)
| # | Exercise | Sets | Lifters |
|---|---|---|---|
| 1 | Leg press | 3,599 | 286 |
| 2 | Seated dumbbell press | 3,315 | 313 |
| 3 | Barbell bent-over row | 3,221 | 252 |
| 4 | Barbell bench press | 3,221 | 210 |
| 5 | Leg extension | 3,066 | 271 |
| 6 | Seated leg curl | 2,946 | 248 |
| 7 | Dumbbell bench press | 2,901 | 263 |
| 8 | Low incline dumbbell press | 2,636 | 211 |
| 9 | Chest press machine | 2,394 | 176 |
| 10 | Seated cable row | 2,179 | 173 |
By number of lifters, the seated dumbbell press is number one (313 lifters), by sets the leg press. The Romanian deadlift is only 11th (2,148 sets) and the barbell back squat 12th (2,118 sets): deadlifts and squats are popular topics of conversation, but in the gym the Finnish lifter does leg presses, leg extensions and leg curls. Part of this is explained by SisuLift's program generation, which picks exercises based on the gym's equipment and the user's experience, but exercises are also swapped freely. Technique and animation for every exercise is in the exercise library.
How fast weights go up: 8-week change by exercise
For every lifter and exercise we calculated an estimated one-rep max (e1RM, Epley formula from load and reps, only sets of 1-12 reps) from the best set of the first training week and compared it with the best set of weeks 8-9. Only those with entries at both points are included, i.e. those who kept going for eight weeks. That makes the figures selected: dropouts are not visible, so the true average rate is somewhat lower.
Median change in estimated 1RM from the first week to weeks 8-9
| Exercise | Median change, 8 weeks | Share who improved | Lifters |
|---|---|---|---|
| Leg press | +9.5% | 79% | 33 |
| Leg extension | +8.8% | 63% | 30 |
| Barbell back squat | +6.6% | 82% | 22 |
| Romanian deadlift | +6.1% | 71% | 24 |
| Barbell bent-over row | +5.3% | 71% | 28 |
| Barbell bench press | +4.2% | 71% | 34 |
| Seated leg curl | +2.4% | 56% | 27 |
| Seated dumbbell press | 0% | 49% | 35 |
| Low incline dumbbell press | 0% | 48% | 25 |
- Legs progress fastest: leg press and back squat go up 7-10 percent in eight weeks. Barbell bench press goes up about 4 percent, which on a 70 kg e1RM is 3 kilos. That is a realistic rate, not a bad one.
- For dumbbell exercises the median change is zero. The reason is the equipment step: when dumbbells go up in 2 kg increments and the working weight is 15 kg, the next step is a 13 percent jump. In these exercises progression happens through reps, and Plotkin's finding (rep progression works) is exactly for this.
- The spread is wide: on the bench press the best quarter gained more than 12 percent and the weakest quarter went down. Eight weeks is a short time, and one bad day in week 8 shows in the number.
What this means for you: if your bench goes up 2.5 kg a month, you are at the dataset's median. If your leg press has not moved in eight weeks, something is missing: usually reps are not taken to the top of the range before the load is raised, or nutrition is not enough. A workout log is the only way to know which.
How hard people train: the RPE distribution
91 percent of working sets have a logged RPE, or rating of perceived exertion, on a 1-10 scale where 10 is complete failure and 8 means about two reps in reserve (Helms et al. 2016). The distribution looks like this:
Distribution of logged RPE values (101,601 sets with RPE)
| RPE | Share of sets | What it means |
|---|---|---|
| 6 or below | 3% | At least 4 reps in reserve, light |
| 7 | 12% | 3 reps in reserve, the floor for a working set |
| 8 | 53% | 2 reps in reserve, the level the research recommends |
| 9 | 25% | 1 rep in reserve, hard |
| 10 | 6% | Nothing left, failure |
85 percent of sets are done at RPE 8 or harder and 31 percent at RPE 9-10. That is harder than the research recommends for muscle growth: 1-3 reps in reserve produces nearly the same growth as failure, with less fatigue. RPE 8 is by far the most common value, though, and it is worth remembering it is the lifter's own estimate: beginners typically underestimate reps in reserve, feeling a set as RPE 9 when it was a 7. Whether Finnish lifters train hard enough does not look like a problem. Whether 6 percent of sets should be taken to failure is something to think about if recovery is struggling.
What a typical session looks like
- Working sets per session: median 17, interquartile range 15-20.
- Duration: median 60 minutes, interquartile range 48-74.
- Pace: about one working set every three and a half minutes including rest.
- Per week: median 2 sessions, 44 percent of weeks have 3 or more. More in How often should you go to the gym.
17 sets in an hour is an efficient session. Per muscle group it means three sessions a week give every large muscle group 10-15 sets, the lower half of the research's dose-response range. That is enough for most people to progress, and it is exactly the amount that fits into an hour.
How SisuLift's weekly progression applies this
Every week SisuLift calculates a suggestion for each exercise based on the logged sets. The suggestion is shown with its reasoning, and the user accepts or skips it. The principles are the same as above, and the rules live in the app's code, not in marketing copy:
- Double progression: when every set reaches the top of the rep range, the suggestion is a load increase. The increase follows the exercise's equipment step (barbell, dumbbell, machine or the user's own setting), not a percentage.
- Rep progression: if the load cannot go up because of the equipment step, or reps fell short of target, the suggestion is more reps within the range. This is why dumbbell exercises do not get stuck.
- Adding a set: when an exercise has stalled in both load and reps, the next lever is an extra working set.
- Stall detection: if the same load and reps repeat week after week, the suggestion changes instead of repeating itself.
- Deload from data, not from the calendar: a deload week is suggested when average RPE rises above 8.5 and has risen compared with the previous two weeks while recovery data is not green, when session completion drops below 80 percent, or when the recovery score drops by more than 15 percent. An age-dependent calendar cap comes in only as a safety limit.
- Mesocycles: an accumulation phase is followed by an intensification phase where reps drop and loads rise, and then a deload. This way overload is not an endless linear climb that inevitably stalls.
All of this can be done by hand in a notebook, and many people do. The app invents nothing new, it just removes the remembering and calculating between sets. The logged data is what matters, and logging is unlimited on the free tier.
How to apply progressive overload yourself
- Pick a rep range per exercise, for example 6-10 for big lifts and 10-15 for isolation exercises.
- Keep the load the same until every set hits the top of the range at RPE 7-9.
- Raise the load by the smallest possible step (2.5 kg on a barbell, 1-2 kg on dumbbells, use micro plates) and start from the bottom of the range.
- Log every set. Without a log you do not know whether you are at the top of the range.
- If nothing goes up in three weeks, check sleep, calories and protein (1.6-2.2 g/kg, read how much protein per day) before changing the program.
- Every 5th to 8th week, or when RPE runs away, take a deload week: same exercises, half the sets.
You can calculate your estimated one-rep max with the 1RM calculator or with the Epley formula: load × (1 + reps / 30). 80 kg × 8 reps is about 101 kg.
Sources
- Plotkin D et al. (2022). Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations. PeerJ 10:e14142.
- Schoenfeld BJ, Ogborn D & Krieger JW (2017). Dose-response relationship between weekly resistance training volume and increases in muscle mass: a systematic review and meta-analysis. Journal of Sports Sciences 35:1073-1082.
- Helms ER et al. (2016). Application of the repetitions in reserve-based rating of perceived exertion scale for resistance training. Strength and Conditioning Journal 38(4):42-49.
- Grgic J et al. (2018). Effect of resistance training frequency on gains in muscular strength: a systematic review and meta-analysis. Sports Medicine 48:1207-1220.
→ Read also: Workout log guide | Exercise library