How we rate
“Strong” = several concordant meta-analyses or systematic reviews. “Moderate” = one synthesis, or several controlled trials. “Limited” = early trials only. The rating is about the quality of the studies, not about how useful the supplement is.
Milk
Consumed after the training session, milk led to greater lean mass gains than a sugary drink in beginners, and it rehydrates better than water. Bones and heart: cohorts find no link.
Benefits
- Lean mass: in 56 young male beginners, skimmed milk right after the training session then one hour later, during 12 weeks of weight training, increased muscle fibers and lean mass more than a soy or sugary drink.
- In women: in 20 young women, the same thing led to a gain of 1.9 kg of lean mass against 1.1 kg with a sugary drink of the same calories, and a loss of 1.6 kg of fat against 0.3.
- After 60 years: in a meta-analysis of 10 trials and 574 participants, milk proteins added to weight training lead to 0.74 kg more lean mass gained.
- Rehydration: after losing 1.8% of their body weight in sweat, 11 athletes drinking skimmed milk urinated 611 mL over 5 hours compared to 1,184 mL with water, and remained better hydrated than with a sports drink.
- Recovery: 500 mL of milk after exercise that damages muscle limited strength loss and soreness over 72 hours, more markedly in women than in men.
- Bones in adolescence: in 28 boys aged 13 to 17, 3 glasses of milk per day during 12 weeks of weight training doubled the bone density gain compared to a juice (0.028 versus 0.014 g/cm²).
Precautions
Lactose: the authors of the rehydration trial exclude people who digest it poorly. Prostate: a meta-analysis of 11 case-control studies associates milk with more prostate cancers (odds ratio 1.68), without proving causation. Limits: after 50 years: in 180 men aged 50 to 79, 400 mL per day of an enriched milk for 18 months added nothing to weight training, neither muscle nor strength. Strength: in young beginners, milk made them gain more muscle than soy or sugar, but no more strength. Fractures: no link between milk and hip fractures in women in cohorts; in 97,811 Danes, drinking more milk throughout life, via genetics, does not change the risk. Heart and longevity: 200 mL per day changes neither mortality, nor coronary heart disease, nor strokes in cohorts; studies are too different to conclude on mortality. Colon: fewer colon cancers in men who drink the most (relative risk 0.74), nothing in women; these are only cohorts.
Recommended dosage
From 400 mL per day (men over 50) to 2 times 500 mL around the training session (young beginners) in the trials.
How to take it
- Timing: in positive trials, milk was consumed right after the training session, and sometimes one hour later or before bedtime.
- Quantity: 2 times 500 mL of skimmed milk in the trials on beginners; 2 times 250 mL of a protein-enriched milk (30 g each) in already trained men.
- Duration: 6 to 12 weeks of weight training in positive trials.
- Whole or skimmed: after the training session, whole milk caused the leg to uptake more of one amino acid (threonine) than skimmed milk, in a small single-session study.
- After exercise in the heat: milk rehydrates better than water, unless you digest lactose poorly.
- Without weight training, little effect: in adults over 50, milk alone did not result in lean mass gains.
Did you know?
After losing 1.8% of their body weight in sweat, athletes who drank skimmed milk urinated about twice as little over 5 hours than with water or a sports drink: 611 mL versus 1,184 and 1,205 mL.
What the studies say
This meta-analysis examined the effects of milk protein supplementation combined with resistance training in older adults. The results indicate that this combination is effective in increasing lean mass, although it had no significant effect on fat mass or total body weight. Lean mass gains were more pronounced in studies with a larger number of participants or those suffering from age-related health problems.
Hidayat K, Chen GC, Wang Y, Zhang Z, Dai X, Szeto IMY, Qin LQ. — The journal of nutrition, health & aging (2018) — View the source study
Pairs well with
For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more