Volume, intensity and RIR: reading a strength plan
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Four numbers that describe different things
3×5 means three sets of five repetitions, not the load or effort. 80% of 1RM is a proportion of the one-repetition maximum, not the number of repetitions remaining. RIR estimates how many more repetitions could still be completed. Reading a plan requires keeping these details separate. [1][2]
Volume: what is being counted?
| Measure | Illustrative example | Limit |
|---|---|---|
| Total repetitions | 3×5 = 15 repetitions | Does not distinguish load and effort |
| Weekly sets | 3 sets Monday + 3 Thursday = 6 | Exercise and counting criteria still matter |
| Volume-load | 3×5×60 kg = 900 kg | Not mechanical work or equivalent dose across exercises |
The examples count working sets only; any warm-up is excluded. The kilogram total does not account for displacement, body or machine mechanics, so it cannot establish that 900 kg of squats equals 900 kg of leg press. Check how a source defines volume before comparing programs.
Load intensity versus effort intensity
Percentage of 1RM describes relative load. Proximity to failure describes remaining margin within a set. The RIR review distinguishes these meanings of intensity: the same load and repetitions can involve different efforts between people or days. [2]
Example: with a measured 100 kg maximum, 80 kg is 80%. That calculation does not establish that exactly five, eight or ten repetitions are possible that day. A precise percentage does not remove performance variability.
RIR and RPE: estimates, not sensors
RIR 2 means estimating two further repetitions before task failure. The 2024 review includes 31 studies and 855 participants, mostly adult men. Scales appear useful in particular contexts; predictions tend to be more accurate near failure, with limits involving experience and exercise selection. This is not an exact measurement or a reason to take every set to failure to check the estimate. [2]
On RIR-based RPE scales, RPE 9 can describe one repetition remaining. Not all RPE scales use the same meaning: session RPE, breathing effort and a single set’s RPE cannot be exchanged without explanation. An 8 or 9 alone does not determine a universal load.
What the ACSM 2026 synthesis shows
The synthesis of 137 reviews and over 30,000 participants separates strength, hypertrophy and power. Heavier loads emerge as useful for strength; volume matters for hypertrophy; power also involves training mode and concentric velocity. These are not the same prescription under different labels. Much evidence concerns healthy adults and less-trained people, not exclusively experienced endurance athletes. [1]
Failure training and periodisation did not show a consistent advantage across all outcomes in the synthesis. This does not establish that they are always useless: it prevents treating them as universal requirements. Read a specific program’s choices within its own rules rather than adding them from an isolated sentence.
An understandable diary entry
“Squat, 3×5, 60 kg, estimated RIR 2 on the final set, rests recorded” separates quantity, load and effort. It is a logging example, not a recommended session. Without rest information, time between sets is unknown; without an RIR criterion, the reported effort is unclear.
The exercise catalogue helps identify names and equipment. The programs explain different structures and progressions. These definitions help read them, not merge them into a new program.
Sources and limits
- ACSM, Resistance Training Prescription for Muscle Function, Hypertrophy, and Physical Performance, 2026. Overview of reviews with varied populations and goals.
- RIR scales in resistance training: scoping review, 2024. 31 studies; estimation and generalisation limits.
Sources checked on 29 October 2026.