How to track strength training progress: the numbers that matter
Logging your sessions is only useful if you know what to get out of them. Here are the numbers that actually measure progress, and above all how to read them.
Arestis in brief
Arestis is a workout log app available on iPhone and Android. It calculates your training volume, estimated 1RM and personal records from your sessions, and shows how they change over time as charts.
Join the beta →Why measure, not just feel
How you feel tells one story, the numbers tell another. A session that feels easy might be your best of the month, and an exhausting one might just be a bad night's sleep. Over several months, data helps complete what you feel during your sessions.
The catch is that "I'm progressing" means nothing until you decide what you're measuring. Lifting heavier, doing more reps, handling more volume or recovering faster are four different kinds of progress, and they don't move at the same pace.
The numbers that matter
Weight
The most obvious one: how much you lift. It's the easiest number to read, but also the most misleading on its own. Going from 60 kg × 8 to 65 kg × 5 isn't necessarily progress, while going from 60 kg × 8 to 60 kg × 10 is, even though the weight didn't change.
Volume
Volume combines reps and weight. It's the most honest number for judging a whole session.
In practice, 4 sets of 8 reps at 60 kg add up to 1,920 kg of volume. If the next week you do 4 × 9 at 60 kg, your volume rises to 2,160 kg: you've progressed by 12.5%, while your top weight hasn't moved at all.
Tonnage
Tonnage is volume added up over a period: a week, a month, a training block. It's used to judge your overall workload rather than a single session.
It's a measure of quantity, not quality. Rising tonnage means you're handling more work. It doesn't tell you whether you've gotten stronger.
Estimated 1RM
Your 1RM is the maximum weight you could lift for a single rep. Testing it for real is tiring and risky, so it's estimated from a normal set. The most widely used formula is Epley's:
A set of 8 reps at 60 kg gives an estimated 1RM of 76 kg. The point isn't the number itself, which remains an approximation, but how it changes: the estimated 1RM lets you compare how your strength evolves while accounting for both the weight and the number of reps.
An estimate is still an estimate. It's reliable up to 8 or 10 reps, much less beyond that. On a set of 20 reps, the formula overestimates by a wide margin.
Frequency
How many sessions per week, and how often you train each muscle group. It's the most overlooked number, even though it often explains a plateau: three weeks at one session instead of four, and progress stops for no apparent reason.
Bodyweight and measurements
They provide context. Getting stronger while ten kilos heavier doesn't read the same as getting stronger at a stable weight. Measurements change too slowly to check every week, but they say a lot over six months.
How to read your progress
| You see | Likely meaning |
|---|---|
| Same weight, more reps | Real progress. It's the normal pattern between two weight jumps. |
| Volume up, 1RM stable | You're handling more work without getting stronger. Useful for building muscle, not enough if strength is the goal. |
| 1RM up, volume stable | You're getting stronger. Typical of training with short, heavy sets. |
| Everything flat for 3 weeks | Normal. Progress is never linear. |
| Everything flat for 3 months | Something needs to change: program, recovery, nutrition or frequency. |
| Sudden drop in one session | Look at the context before concluding. Sleep, shorter rests, a busy week. |
Common pitfalls
- Comparing sessions that aren't comparable. Two minutes of rest instead of four completely changes a performance. Without logging rest time, you're comparing different things.
- Counting warm-up sets in your volume. Your tonnage gets artificially inflated and you think you're progressing when you just warmed up longer.
- Checking your charts every day. Nothing moves in a single session. Noise drowns out the signal, and you end up worrying for nothing.
- Tracking only one number. Weight alone hides progress in reps. Volume alone hides strength gains.
How often to look
Once a month is enough to judge a trend. Before each session, however, it's worth checking what you did last time on that specific exercise: that's what tells you what to aim for today.
The two serve different purposes. One guides today's session, the other tells you whether your program works.
Tracking your progress with Arestis
All these calculations are tedious by hand, which is exactly why people stop doing them. Arestis handles them from what you log during the session:
- Volume and tonnage calculated automatically, warm-ups excluded
- Estimated 1RM using the Epley formula, with its chart per exercise
- Personal records detected and highlighted at the end of the session
- Comparison with your previous session on the same exercise, as a percentage
- Muscle group breakdown, to spot what you neglect
- Bodyweight and measurements tracked in the same place, with their charts
To know what to write down during the session, the workout log guide covers the useful details. And if you're comparing apps, the workout app comparison shows which ones restrict access to statistics.