Term and system context

Short version Rep ranges describe which repetition window you train a set in. A common heuristic:

• 1–5 reps: focus on maximal strength (high load, high CNS stress).
• 6–12 reps: classic hypertrophy zone (good mix of tension, volume, technique).
• 13–30 reps: higher rep counts, more metabolic stress, technically demanding under fatigue.

Current evidence suggests: hypertrophy is possible in a broad spectrum of about 5–30 repetitions, as long as you:

• train close enough to failure (typically RIR 0–3),
• accumulate enough volume in the corridor between MEV and MAV,
• and your system of metabolism, TDEE, sleep and stress is on board.

For hardgainers, rep ranges are a control lever for stimulus quality: you can place exercises in zones where you feel tension well, can hold technique and where the SFR is solid – instead of blindly believing “8–12 reps = hypertrophy”.

Measurement and implementation

In practice, you tie rep ranges to load (in % of your 1RM – One-Rep Max) and RIR. For hardgainers it works well to use a few clearly defined rep ranges per exercise that you track consistently.

• Typical mapping: 3–5 reps ≈ 80–90% 1RM, 6–10 ≈ 65–80%, 10–15 ≈ 55–70%, 15–30 ≈ 30–55%. These are orientation values, not rigid laws.
• Exercise-specific steering: heavy compound lifts (squats, deadlifts, bench press) often in the 3–8 rep range; machines and isolation work (leg extensions, lateral raises, curls) often in the 8–15 or 12–20 range.
• RIR as safety net: The effective effort matters more than the raw rep count. `RIR 1–2` in a 6–10 set and `RIR 1–2` in a 12–15 set can deliver a very similar hypertrophy stimulus.

Steering in a gaining phase (guardrails)

• Main zone for hardgainers: Do a lot of work in a mid-range of about 5–15 reps – a strong balance of tension, volume, technique and SFR.
• Combine heavier and lighter zones: Plan 1–2 exercises per muscle group with lower reps (for example 5–8) and 1–2 exercises with higher reps (for example 10–15 or 12–20).
• Use extremes sparingly: ultra-heavy singles/doubles and very high rep work (>25) can have their place, but should be time-limited and clearly justified – not your default.
• System, not dogma: Always judge rep ranges in the context of weekly volume, training frequency, RIR and recovery – see also Myth #2: More training = more muscle.

Practice – 14-day orientation

• Day 0: For each main lift, set a clear rep range (for example squats 5–8, rows 8–12, lateral raises 12–20). Define target RIR (usually 1–3), volume band per muscle group and training frequency.
• Daily: Log loads, reps, RIR, perceived technique quality and pump. Optionally add a short fatigue note (“fresh”, “ok”, “wrecked”). Once per week, track bodyweight and relevant measurements.
• Day 14:
  • If load and reps are climbing and you feel solid but not destroyed: keep your rep ranges, adjust volume only cautiously.
  • If sets in the target zone regularly fail (for example you are consistently far below the lower bound): check technique, load selection and RIR execution – do not reflexively throw in more volume or exotic rep schemes.
  • If you are constantly sore but see little progress, that is a textbook case for Myth #8: You need soreness to grow! – audit volume, SFR and rep ranges critically.

Common misconceptions

• “Only 8–12 reps build muscle.” Hypertrophy is possible in a broad spectrum of about 5–30 reps as long as load, RIR and volume are on point. The “8–12 range” is practical – but not a magic boundary.
• “High reps are just pump fluff.” Strategically used higher rep ranges (for example 12–20) on machines or isolation work can be extremely productive at a good SFR, with stable technique and RIR 1–3 – see also Myth #9: No pump, no muscle growth.
• “I have to take every set to failure.” For most hardgainers, the majority of sets at RIR 1–3 in an appropriate rep range is more productive than constant failure training with sloppy technique and unnecessary fatigue – especially when combined with RIR and SFR.

Further resources

Note: Content provides general orientation only; individual adjustments can be useful or required.