Hypertrophy Evidence Notes
All topics

Sleep, Alcohol, Carbs, and Fat

Sleep at least 7 hours. Heavy drinking after training cuts muscle protein synthesis by 20–40%.

23Last reviewed Verdicts

Verdicts on this page5
  1. BProbably trueAdults need at least 7 hours of sleep.
  2. CMay be trueSleep loss visibly lowers muscle protein synthesis in the short term.
  3. CMay be trueDrinking heavily after training lowers muscle protein synthesis by about 24%, even with protein.
  4. CMay be trueThe minimum carb intake for hypertrophy is unknown. Extra carbs improved lifting performance mainly when training fasted or in long sessions of more than 10 sets per muscle.
  5. BProbably trueCutting fat drastically lowers testosterone.

Bottom line

  • Sleep 7–9 hours every night, on a consistent schedule
  • Avoid heavy drinking after training. The effect of occasional moderate drinking has not been studied
  • Aim for 3–5 g/kg of carbs (210–350g). Don’t let fat drop below 0.5 g/kg (35g)

Sleep

BProbably true

Adults need at least 7 hours of sleep.

Consensus of the American Academy of Sleep Medicine and the Sleep Research Society (Watson 2015).

CMay be true

Sleep loss visibly lowers muscle protein synthesis in the short term.

  • One night of total sleep deprivation: muscle protein synthesis −18%, cortisol +21%, testosterone −24% (Lamon 2021)
  • Five nights of 4-hour sleep lowered myofibrillar protein synthesis from 1.53 to 1.24 %/day. High-intensity interval exercise brought it back (Saner 2020)
  • One short night barely affects strength, but several in a row reduce output on multi-joint lifts (Knowles 2018)

No RCT has restricted sleep for months and measured hypertrophy directly. The evidence so far is mechanistic.

Alcohol

CMay be true

Drinking heavily after training lowers muscle protein synthesis by about 24%, even with protein.

1.5g of alcohol per kg of body weight (about 105g at 70kg, roughly 10 drinks) caused −24%. With carbs instead of protein, it was −37% (Parr 2014). The study had 8 subjects and a single session. There is no data on regular moderate drinking.

Carbs and fat

CMay be true

The minimum carb intake for hypertrophy is unknown. Extra carbs improved lifting performance mainly when training fasted or in long sessions of more than 10 sets per muscle.

Systematic review of 49 studies (Henselmans 2022). 3–5 g/kg is given as a guideline (Iraki 2019).

BProbably true

Cutting fat drastically lowers testosterone.

In a meta-analysis, low-fat diets lowered total testosterone (effect size −0.38, Whittaker 2021). Whether a small change within the normal range affects hypertrophy is unknown, but 0.5 g/kg is a safe floor.

References

  1. Watson NF et al. 2015. Recommended Amount of Sleep for a Healthy Adult. J Clin Sleep Med. PMID 25979105 ↩
  2. Lamon S et al. 2021. The effect of acute sleep deprivation on skeletal muscle protein synthesis and the hormonal environment. Physiol Rep. PMID 33400856 ↩
  3. Saner NJ et al. 2020. The effect of sleep restriction, with or without high-intensity interval exercise, on myofibrillar protein synthesis in healthy young men. J Physiol. PMID 32078168 ↩
  4. Knowles OE et al. 2018. Inadequate sleep and muscle strength: Implications for resistance training. J Sci Med Sport. PMID 29422383 ↩
  5. Parr EB et al. 2014. Alcohol ingestion impairs maximal post-exercise rates of myofibrillar protein synthesis following a single bout of concurrent training. PLoS One. PMID 24533082 ↩
  6. Henselmans M et al. 2022. The Effect of Carbohydrate Intake on Strength and Resistance Training Performance: A Systematic Review. Nutrients. PMID 35215506 ↩
  7. Iraki J et al. 2019. Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review. Sports (Basel). PMID 31247944 ↩
  8. Whittaker J, Wu K. 2021. Low-fat diets and testosterone in men: Systematic review and meta-analysis of intervention studies. J Steroid Biochem Mol Biol. PMID 33741447 ↩