The fitness industry thrives on complexity. New programs, new supplements, new “secrets” every week.

But the research on muscle building is actually pretty clear. Here’s what we know works — and what’s just noise.

The Three Things That Actually Matter

1. Progressive Overload

What it means: Gradually increasing the demands on your muscles over time.

Why it matters: Your body adapts to stress. If the stress doesn’t increase, adaptation stops.

How to do it:

  • Add weight to the bar (most straightforward)
  • Add reps with the same weight
  • Add sets
  • Improve technique (more tension on target muscle)

The research: Progressive overload is the single most important variable for hypertrophy. Studies consistently show that without it, muscle growth stalls [1].

2. Sufficient Volume

What it means: Total work done (sets × reps × weight).

The sweet spot: Research suggests 10-20 hard sets per muscle group per week for most people [2].

  • Beginners: 10-12 sets/muscle/week is plenty
  • Intermediate: 12-16 sets/muscle/week
  • Advanced: 16-20+ sets/muscle/week

Hard sets means sets taken close to failure (within 1-3 reps of not being able to complete another rep with good form).

Caveat: More isn’t always better. Recovery matters. If you’re not recovering between sessions, you’re doing too much.

3. Protein

What it means: Adequate dietary protein to support muscle protein synthesis.

The number: 0.7-1g per pound of body weight per day handles it for most people [3].

  • 180 lb person: 130-180g protein/day
  • Distribution matters somewhat: spreading intake across meals is slightly better than one massive dose

The research: Below this threshold, gains suffer. Above it, you’re just making expensive urine.

What Matters Less Than You Think

Exercise Selection

Squats vs. leg press. Barbell vs. dumbbells. Machines vs. free weights.

The truth: They all work if progressive overload and volume are equated. Pick exercises you can do consistently, safely, and through a full range of motion.

Compound movements (squat, deadlift, bench, row, press) are efficient because they train multiple muscles. But they’re not magic.

Rep Ranges

“8-12 for hypertrophy” is a myth. Research shows muscle growth across a wide range of rep ranges [4]:

  • 5-8 reps: builds muscle (and strength)
  • 8-12 reps: builds muscle
  • 12-20 reps: builds muscle (if taken close to failure)
  • 20-30 reps: still builds muscle (though it’s miserable)

What actually matters: Taking sets close to failure. Whether that’s 6 reps or 25 reps, the stimulus is similar.

Practical advice: Use a variety. Heavy work (5-8) for compounds. Moderate (8-12) for most accessories. Higher reps (12-20) for isolation and joint-friendly options.

Training Frequency

Training a muscle 1x/week vs. 2x/week vs. 3x/week — when volume is equated, results are similar [5].

Why frequency might still matter:

  • Spreading volume across more sessions = better recovery
  • More practice with movement patterns
  • Easier to maintain technique when not fatigued

Practical advice: 2x/week per muscle group is a good default. But if you recover well from 1x/week or prefer 3x/week, that’s fine too.

Supplements

What works (a little):

  • Creatine monohydrate — 3-5g/day. Well-researched, small but real benefit.
  • Caffeine — improves performance, indirectly helps gains
  • Protein powder — just food, convenient for hitting protein targets

What’s overhyped:

  • BCAAs (just eat protein)
  • Test boosters (don’t work)
  • Most pre-workouts (just caffeine + marketing)
  • Fat burners (worthless)

Supplements are maybe 1-2% of results. Don’t obsess over them.

The Stuff That Actually Kills Gains

Poor Sleep

Sleep is when you recover and grow. Chronic sleep deprivation tanks testosterone, increases cortisol, and impairs muscle protein synthesis [6].

Minimum: 7 hours. Better: 8+.

Excessive Stress

Chronically elevated cortisol impairs recovery. This includes:

  • Psychological stress
  • Under-eating dramatically
  • Too much training volume
  • Not enough rest days

Inconsistency

The best program you don’t follow beats the worst program you do… wait, no. The program you actually follow beats everything.

Missing workouts, hopping between programs, and majoring in the minors are the biggest gains killers.

A Simple Framework

If you’re not growing:

  1. Are you progressively overloading? Weights going up over months?
  2. Are you doing enough volume? 10-20 hard sets per muscle per week?
  3. Are you eating enough protein? 0.7-1g per lb body weight?
  4. Are you sleeping enough? 7+ hours?
  5. Are you consistent? Actually showing up?

Fix those five things before you blame genetics or buy another supplement.

References

  1. Schoenfeld BJ. “The mechanisms of muscle hypertrophy and their application to resistance training.” J Strength Cond Res. 2010.

  2. Schoenfeld BJ, et al. “Dose-response relationship between weekly resistance training volume and increases in muscle mass.” J Sports Sci. 2017.

  3. Morton RW, et al. “A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength.” Br J Sports Med. 2018.

  4. Schoenfeld BJ, et al. “Effects of Low- vs. High-Load Resistance Training on Muscle Strength and Hypertrophy in Well-Trained Men.” J Strength Cond Res. 2015.

  5. Schoenfeld BJ, et al. “Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy.” Sports Med. 2016.

  6. Dattilo M, et al. “Sleep and muscle recovery: endocrinological and molecular basis for a new and promising hypothesis.” Med Hypotheses. 2011.

Have questions? Find me on Twitter @drmob.