Effects of Drinking Milk Following Exercise
Associate Professor, Department of Kinesiology-Exercise Metabolism Research Group; Associate Member, Faculty of Health Sciences, McMaster University
Skeletal muscle is important for regulation of blood glucose as well as blood lipids as it is the largest site for glucose disposal and lipid oxidation. Thus, resistance exercise (to gain, or prevent loss of even a small amount of muscle) may have important health benefits.
The study
In an acute study, we found that drinking milk promoted greater gains in muscle protein than drinking the equivalent amount of a soy beverage.1 We then examined, in a longer-term study, whether what young healthy men drank after their resistance exercise routine affected how much muscle they gained and fat they lost. We compared skim milk to a soy drink with equivalent protein and energy and to a carbohydrate solution (maltodextrin) typical of sports drinks.2 Fifty-six healthy young men lifted weights five days/week for 12 weeks and were randomly assigned to one of three groups: fat-free milk (n=18), fat-free soy beverage (n=19) or carbohydrate solution (n=19). The drinks were consumed immediately and one hour after exercise. Muscle mass, muscle fibre size, strength, and fat mass were assessed pre- and post-training.
The results
Muscle mass gains from baseline were 6.2% (3.9 kg) in the milk drinkers, 4.4% (2.8 kg) in the soy drinkers, and 3.7% (2.4 kg) in the carbohydrate drinkers (p<0.05 milk vs. soy and carbohydrate). There was also a tendency for milk drinkers to gain more strength especially in the leg muscle groups (p=0.08). Gains in muscle fibre size mirrored those seen in muscle mass.2
Milk drinkers also showed a significantly greater reduction in their fat mass, which declined by 5.5% (0.8 kg) from baseline (p<0.01) compared to both the carbohydrate group, who reduced their fat mass by 3.4% (0.5 kg), and the soy drinkers who lost only 1.5% of their baseline fat mass (0.2 kg).2
Milk has also been shown to be an effective rehydration aid, better than sports drinks, following exercise.3 Thus, for athletes or anyone interested in maximizing the gains from their workout, milk is a good post-exercise choice.
Highlights
- Milk following resistance exercise promotes greater gains in muscle and losses in body fat than soy or sport drinks.
- Milk is an effective post-exercise rehydration aid.
- Consumption of milk after exercise promotes greater gains in muscle protein which is important in repairing damage caused by the exercise itself.
References
- Wilkinson SB et al. Consumption of fluid skim milk promotes greater muscle protein accretion following resistance exercise than an isonitrogenous and isoenergetic soy protein beverage. Am J Clin Nutr 2006; 85:1031-1040.
- Hartman JW et al. Consumption of fat-free fluid milk after resistance exercise promotes greater lean mass accretion than does consumption of soy or carbohydrate in young, novice, male weightlifters. Am J Clin Nutr 2007;86:373-381.
- Shirreffs SW, Watson P and Maughan RJ. Milk as an effective post-exercise rehydration drink. Br J Nutr 2007;98:173-180.
Keywords: health studies
