Core training principles

Progressive overload, double progression, effort, weekly volume, frequency, rep ranges, rest, tempo, exercise order, deloads and the warm-up.

Muscle grows when you train it hard enough, often enough and progressively harder over time, then recover. These ten rules apply at every level.

1. Progressive overload. Aim to beat last time: +1–2 reps, or about +2.5 kg on upper-body lifts / +5 kg on lower-body lifts once you hit the top of your rep range. Without progression over time, growth stalls.
2. Double progression (the simplest system). Pick a range, e.g. 3 × 8–12. Stay at the same weight until you get 12 on all sets, then add weight and drop back to 8. FitAtlas works out these targets for you after every workout.
3. Effort: reps in reserve (RIR). RIR is how many more clean reps you could have done. Most working sets should end 1–3 reps short of failure. Beginners stay at 2–3 RIR; advanced lifters can take isolation lifts to 0–1 RIR.
4. Volume. Count hard sets per muscle per week: beginner 6–10, intermediate 10–16, advanced 14–22 (more only for a lagging muscle, short-term). Research links 10+ weekly sets with more growth than fewer than 5.
5. Frequency. Train each muscle about twice a week. When weekly sets are equal, studies show similar growth from 1 or 2+ sessions, but splitting 16 sets into two sessions of 8 keeps every set high quality, so 2× is the practical choice.
6. Rep ranges. Anything from about 5 to 30 reps builds similar muscle when sets are taken close to failure. Use 4–8 for heavy compounds (strength), 8–15 for most hypertrophy work, and 12–25 for small muscles (calves, delts, abs, forearms).
7. Rest between sets. Compounds 2–3 minutes (up to 4 on heavy squats and deadlifts); isolation 60–90 seconds. Very short rests cut the reps you can do.
8. Tempo and control. Lower the weight in 2–3 seconds, pause briefly in the stretch and lift with intent. Use a full range of motion; research suggests training at long muscle lengths may give extra growth.
9. Exercise order. Biggest, most technical lift first while fresh; isolation last. Prioritise a weak muscle by training it first.
10. Deloads. Every 4–8 weeks (or when joints ache, sleep drops and strength stalls), take one easier week at about half your usual sets and 3–4 RIR.

Warm-up for every session (8–10 minutes)

3–5 minutes of light cardio → dynamic mobility for the joints you'll use → ramp-up sets on the first lift (e.g. bar × 10, 50% × 6, 70% × 4, 85% × 2) → start your working sets.

Evidence behind this chapter

• Schoenfeld, Ogborn & Krieger (2017), dose–response of weekly sets and hypertrophy, Journal of Sports Sciences
• Schoenfeld, Grgic & Krieger (2019), training frequency and hypertrophy meta-analysis, Journal of Sports Sciences
• Schoenfeld et al. (2017), low- vs high-load training meta-analysis, Journal of Strength and Conditioning Research
• Schoenfeld et al. (2016), 1- vs 3-minute rest intervals, Journal of Strength and Conditioning Research
• Helms et al. (2016), RPE/RIR in resistance training, Strength and Conditioning Journal

Fact-checked and updated 2026-10-26. General education, not medical advice.