The role of milk as a post-exercise drink

Milk and other dairy products are part of many nutritional guidelines worldwide. Over the past decade research has consistently shown the potential role of milk for sports performance (1). This latest review by James et al., (2018) focuses on the role of milk as a drink after exercise (2).
  • Nutrition is one of the factors that is involved in post-exercise recovery.
  • Specific nutrition requirements depends on the athlete, the intensity of training and individual goals.
  • The review concludes that milk is a cheap and readily available food source that has unique properties that may support post-exercise recovery.

Cow’s milk is widely available in a variety of formats, from fully skimmed (max. 0.5 g/100 ml) to whole milk (at least 3.5 g/100 ml). Moreover, cow’s milk is a natural source of high quality proteins (3.6–3.7 g/100 ml), carbohydrates (4.7–5.0 g/100 ml), water and micronutrients including sodium and calcium. The researchers James et al., (2018) provide a scientific overview of the role of milk as a post-exercise drink. This article summaries their main outcomes.

Muscle protein turnover

Cow’s milk as a post-exercise drink: implications for performance and healthFor athletes optimising muscle mass and function is important for health, day to day activities and sporting performance. Resistance training along with 20 g of high quality dietary protein provides the anabolic stimulus for muscle protein synthesis (MPS) in young adults (2). Skimmed milk naturally provides a readily digestible source of protein (3.6–3.7 g/100 ml), rich in essential amino acids, in particular leucine. Studies have shown it to be more effective at stimulating MPS post-training than an equivalent amount of protein in a soy drink (3, 4).

Milk naturally provides around 3.6 g of protein per 100 ml. These proteins contribute to maximising MPS, and optimise remodelling of skeletal muscle and chronic training adaptations. Milk also provides carbohydrate, water and micronutrients including sodium.

Glycogen resynthesis

Milk naturally provides 4.7–5.0 g of carbohydrate per 100 mL and studies have shown that use of flavoured milks providing additional carbohydrate results in similar muscle glycogen resynthesis to an energy-matched carbohydrate drink. Additionally galactose, one of the monosaccharides present in lactose is a preferential substrate used by the liver.

Rehydration

Milk is considered to be isotonic (osmolality of 280–290 mosmol/kg) (5), and contains sodium, carbohydrate and protein, which all have been shown to independently enhance rehydration (6). According to the researchers, evidence suggests that the milk proteins and carbohydrate concentration work in synergy with the sodium to enhance rehydration.

Muscle soreness

Research show that milk or flavoured milk (500 ml) consumed post-exercise has some benefits in attenuating muscle soreness during subsequent training sessions when compared to a carbohydrate-electrolyte drink or water (7). Whilst the mechanism is currently unclear, the researchers mention that this may improve training quality (2).

Weight management

Maintaining an appropriate body mass and composition is for many athletes essential for optimal sports performance. Recent evidence suggests that consuming 600 ml of skimmed milk post exercise reduced subsequent energy intake when compared with an energy-matched carbohydrate drink (8). Women consuming skimmed milk (2 x 500 ml) post exercise for 12 weeks increased muscle mass and lost more body fat (–1.6 kg vs –0.3 kg) than those consuming the carbohydrate drinks (9). Milk proteins and/or the somewhat thick and creamy texture of milk may suppress appetite and favourably alter energy balance (2).

Unique properties of milk

According to the researchers James et al. (2018) milk ingestion post-exercise offers favourable benefits. Moreover, milk is a cost effective, readily available drink.

References

  1. Roy, B. D. (2008). Milk: the new sports drink? A Review. Journal of the international society of sports nutrition5(1), 15.
  2. James, L. J., Stevenson, E. J., Rumbold, P. L., & Hulston, C. J. (2019). Cow’s milk as a post-exercise recovery drink: implications for performance and health. European journal of sport science19(1), 40-48.
  3. Wilkinson, S. B., Tarnopolsky, M. A., MacDonald, M. J., MacDonald, J. R., Armstrong, D., & Phillips, S. M. (2007). Consumption of fluid skim milk promotes greater muscle protein accretion after resistance exercise than does consumption of an isonitrogenous and isoenergetic soy-protein beverage. The American journal of clinical nutrition85(4), 1031-1040.
  4. Hartman, J. W., Tang, J. E., Wilkinson, S. B., Tarnopolsky, M. A., Lawrence, R. L., Fullerton, A. V., & Phillips, S. M. (2007). 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. The American journal of clinical nutrition86(2), 373-381.
  5. Watson, P., Love, T. D., Maughan, R. J., & Shirreffs, S. M. (2008). A comparison of the effects of milk and a carbohydrate-electrolyte drink on the restoration of fluid balance and exercise capacity in a hot, humid environment. European journal of applied physiology104(4), 633-642.
  6. Evans, G. H., James, L. J., Shirreffs, S. M., & Maughan, R. J. (2017). Optimizing the restoration and maintenance of fluid balance after exercise-induced dehydration. Journal of Applied Physiology, 122, 945-951.
  7. Cockburn, E., Robson-Ansley, P., Hayes, P. R., & Stevenson, E. (2012). Effect of volume of milk consumed on the attenuation of exercise-induced muscle damage. European journal of applied physiology112(9), 3187-3194.
  8. Rumbold, P., Shaw, E., James, L., & Stevenson, E. (2015). Milk consumption following exercise reduces subsequent energy intake in female recreational exercisers. Nutrients7(1), 293-305.
  9. Josse, A. R., Tang, J. E., Tarnopolsky, M. A., & Phillips, S. M. (2010). Body composition and strength changes in women with milk and resistance exercise. Medicine and Science in Sports and Exercise, 42, 1122-1130.