Heavy drinking after hard exercise blunts several short-term markers of recovery, with smaller or no effects at lower doses
Interpretation
Small lab studies, almost all in men, agree in direction at high doses: 1.5 g/kg cut myofibrillar protein synthesis by 24% even with protein in 8 men (Parr 2014); 1 g/kg increased strength loss after extreme eccentric exercise in 10 men (Barnes 2010), while 0.5 g/kg did not (Barnes 2011); 1.5 g/kg replacing carbohydrate reduced glycogen storage in trained cyclists, mainly indirectly (Burke 2003). In 8 women, 0.88 g/kg had no significant effect (McLeay 2017). A large observational study of 4,098 adults showed dose-dependent falls in HRV-derived sleep recovery (Pietilä 2018). No studies of triathletes, masters athletes or long-term adaptation.
Practical implication
Keep heavy drinking away from key sessions, races and the most muscle-damaging sessions; eat a proper recovery meal first; expect lower overnight recovery as dose rises. Extrapolated from short-term lab studies in young, mostly male, non-triathletes; an occasional night out has not been shown to reduce long-term fitness.
Sources
7 sources, independently verified.
After a concurrent session (leg extensions, 30 min steady cycling, 10 x 30 s intervals), 1.5 g/kg alcohol (about 12 standard drinks) reduced myofibrillar protein synthesis by 24% when taken with 25 g whey protein and by 37% with carbohydrate, versus protein alone; anabolic signalling also lower. Single session, single heavy dose, 8 men; no long-term adaptation data.
After 300 maximal eccentric quadriceps contractions, 1 g/kg alcohol increased 36 h losses in peak isometric, concentric and eccentric torque to 40.9%, 42.8% and 44.8%, versus 28.7%, 31.9% and 25.9% with orange juice; the non-exercised leg was unaffected. Extreme damage protocol, men only.
Same eccentric protocol; 0.5 g/kg alcohol versus a matched non-alcoholic drink produced no difference in strength loss at any time point. Men only, small sample.
After 300 maximal eccentric quadriceps actions, 0.88 g/kg alcohol versus an iso-caloric placebo had no main effect on strength recovery; near-significant treatment x time interaction for isometric strength (p = 0.077); creatine kinase unchanged. Small sample, so absence of effect is not proven.
After glycogen-depleting cycling, 1.5 g/kg alcohol replacing carbohydrate lowered glycogen storage at 8 h (24.4 vs 44.6 mmol/kg wet weight) and 24 h (68 vs 82); alcohol added on top of the recovery diet showed a non-significant trend at 8 h and no difference at 24 h. The main effect is indirect, via displaced carbohydrate.
HRV-derived physiological recovery in the first 3 hours of sleep fell by 9.3, 24.0 and 39.2 percentage units at low, moderate and high alcohol intake versus alcohol-free nights; effects similar in men and women and in active and sedentary people. Observational, self-reported intake, employees not athletes.
UK guidance: safest not to drink more than 14 units a week on a regular basis, spread over 3 or more days with several drink-free days; limit the total on any single occasion, drink slowly, with food and alternate with water.