Hypertrophy Evidence Notes
All topics

Progression, Deloads, and Expected Gains

Add reps first, then add weight once you hit the top of the range. Deload when you're worn down.

232Last reviewed Verdicts

Bottom line

  • Progress with double progression. For example, pick a range of 8–12 reps. When every set reaches 12 reps at the target RIR, add 2.5–5% to the weight and start again at 8 reps
  • Deload once every 4–8 weeks, or when fatigue builds up. Cut volume by 30–50% and keep the weight reasonably heavy
  • At 3–4 years of training, month-to-month changes are small. Look at 3–6 month windows: weight at the same reps, circumferences, and photos

Progressive overload

Adding reps and adding weight produce similar hypertrophy.

In an RCT of 43 trained lifters, the rep-progression and load-progression groups had nearly the same results. Only in the rectus femoris did the rep-progression group have a slight edge (Plotkin 2022).

Progressively increasing load nearly doubled hypertrophy compared with keeping it fixed.

Triceps growth was +21.4% vs +11.3% (Kassiano 2026). The subjects were untrained women.

Adjusting load by RPE or RIR (autoregulation) works as well as or better than setting it by %1RM.

  • RPE-based loading matched %1RM, with a possible slight edge for strength (Helms 2018)
  • Autoregulated and fixed programs produced similar strength gains (Hickmott 2022)

Deloads

A deload is “a period of intentionally reduced training demand, to shed fatigue, promote recovery, and prepare for the next block.”

Definition from an expert Delphi consensus (Bell 2023). There is also a survey of practitioners (Rogerson 2024).

A full week off did not change hypertrophy and slightly reduced lower-body strength.

An RCT with a week of complete rest in week 5 of 9 (Coleman 2024, n=39). It tested complete rest, not a lighter-training deload. A deload does not add muscle, so use it as a release valve when fatigue builds up.

Expected gains for trained lifters

Trained lifters grow slowly. Muscle thickness changes by a few percent over 8–12 weeks.

  • RCTs in trained lifters mostly show single-digit percentage changes in muscle thickness over 8–12 weeks (Schoenfeld 2019a, Enes 2024)
  • Over 21 weeks, strength athletes’ muscle cross-sectional area barely changed (−1.8%), while untrained men gained +5.6% over the same period (Ahtiainen 2003). An old, small study
  • Relative hypertrophy is similar in men and women (Refalo 2025b)

The “0.25–0.5kg of lean mass per month in years 3–4” figure is a coaching rule of thumb with no peer-reviewed support.

References

  1. Plotkin D et al. 2022. Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations. PeerJ. PMID 36199287
  2. Kassiano W et al. 2026. Progressive Overload Affects the Magnitude of Muscle Hypertrophy. Med Sci Sports Exerc. PMID 41718594
  3. Helms ER et al. 2018. RPE vs. Percentage 1RM Loading in Periodized Programs Matched for Sets and Repetitions. Front Physiol. PMID 29628895
  4. Hickmott LM et al. 2022. The Effect of Load and Volume Autoregulation on Muscular Strength and Hypertrophy. Sports Med Open. PMID 35038063
  5. Bell L et al. 2023. Integrating Deloading into Strength and Physique Sports Training Programmes: An International Delphi Consensus Approach. Sports Med Open. PMID 37730925
  6. Rogerson D et al. 2024. Deloading Practices in Strength and Physique Sports. Sports Med Open. PMID 38499934
  7. Coleman M et al. 2024. Gaining more from doing less? The effects of a one-week deload period during supervised resistance training on muscular adaptations. PeerJ. PMID 38274324
  8. Schoenfeld BJ et al. 2019a. Resistance Training Volume Enhances Muscle Hypertrophy but Not Strength in Trained Men. Med Sci Sports Exerc. PMID 30153194
  9. Enes A et al. 2024. Effects of Different Weekly Set Progressions on Muscular Adaptations in Trained Males. Med Sci Sports Exerc. PMID 37796222
  10. Ahtiainen JP et al. 2003. Muscle hypertrophy, hormonal adaptations and strength development during strength training in strength-trained and untrained men. Eur J Appl Physiol. PMID 12734759
  11. Refalo MC et al. 2025b. Sex differences in absolute and relative changes in muscle size following resistance training. PeerJ. PMID 40028215