Milk as a sports supplement? Why not! Milk is a relatively inexpensive source of many nutrients, which include protein, calcium, vitamins and minerals.
Milks from different ruminants (e.g. cows, goats, water buffalo) have similar nutrient profiles. However, for the sake of this article we will be talking about cow’s milk as it’s the most available and commonly consumed.
Nutrients in milk
Milk and other dairy foods contain calcium, protein, B vitamins (including B2 and B12), vitamins A and D, phosphorus, potassium, magnesium, zinc and iodine. The table below shows average content for some nutrients of different types of plain cow’s milk (data from 1). A glass of milk has 8 – 9.25g of protein, 12 – 15.25g of carbohydrate (lactose if not lactose-free) and 260 – 310mg of calcium.
A nutrient comparison between dairy and non-dairy milks can be found in the article Is dairy good for you?.
Milk as a sports supplement
The proteins in milk (whey and casein) can enhance muscle protein synthesis post-exercise (2, 3, 4, 5). Remember that milk protein has a very high Digestible Indispensable Amino Acid Score, which measures protein quality due to its digestibility and amino acid profile. The amino acids present in milk are a mix of slow and fast digesting, which favours muscle growth (5). This is how the famous GOMAD (gallon of milk a day) bodybuilding protocol was born.
Milk and dairy foods are rich in calcium, which is important for bone health when combined with exercise. Thus, milk can help increase bone density in children and delay its loss in adults (2).
Milk has similar osmolality (i.e. concentration of electrolytes per kg of fluid) and carbohydrate content than sports drinks, making it a suitable as a rehydration beverage (3). In addition, the protein contained in milk enhances its rehydration properties (2).
Due to its protein content, milk taken post-exercise may help with muscle recovery, lowering the loss of muscle function. However, studies have found inconsistent results, potentially due to the modality of exercise or the study protocol. This is true for resistance and endurance sports and for both male and female athletes (3, 4). I suspect individual genetics and gut health status play a big role in the heterogeneity of results.
A small study with team sports players found that A2 milk (i.e. milk lacking the A1-beta casein in regular milk, which may cause digestive distress) offers similar recovery benefits than regular milk (5).
What about flavoured milk?
In Australia, flavoured milk is considered a core food (e.g. not discretionary or “junk”) due to its calcium content. However, the Dietary Guidelines do recommend choosing plain milk instead (6).
The charts below show a comparison of energy, protein, fat and carbohydrate content between plain and flavoured milks (data from 1).
Should you drink milk as a sports supplement?
Milk is a nutrient-dense food with health benefits for the general population and may offer additional benefits to athletes. However, many people won’t or can’t have regular milk. If this is you, see the table below for alternatives.
|If this sounds like you||Then|
|You are allergic to milk (this is different to being lactose intolerant)||Stay away from milk and try other protein +/- supplements instead|
|You are (or think you are) lactose intolerant||Try lactose-free milk or A2 milk|
|You have IBS (irritable bowel syndrome), IBD (inflammatory bowel disease) or other digestive condition||Try lactose-free milk or A2 milk|
|You have another health condition that requires dietary adjustments||Speak to your dietitian|
|You need to lose weight||Even though milk won’t make you gain weight per se, liquid calories are generally not a good idea when trying to lose weight|
|You are vegan||Try other protein +/- supplements instead|
- Food Standards Australia New Zealand (2014). AUSNUT 2011–13 – Australian Food Composition Database. Canberra: FSANZ. Available at www.foodstandards.gov.au
- Burke, Louise. Clinical Sports Nutrition, 5th Edition. McGraw-Hill Australia, 09/2015. VitalBook file.
- Rankin P, Landy A, Stevenson E, Cockburn E. Milk: An Effective Recovery Drink for Female Athletes. Nutrients. 2018;10(2).
- Alcantara JMA, Sanchez-Delgado G, Martinez-Tellez B, Labayen I, Ruiz JR. Impact of cow’s milk intake on exercise performance and recovery of muscle function: a systematic review. J Int Soc Sports Nutr. 2019;16(1):22.
- Kirk B, Mitchell J, Jackson M, Amirabdollahian F, Alizadehkhaiyat O, Clifford T. A2 Milk Enhances Dynamic Muscle Function Following Repeated Sprint Exercise, a Possible Ergogenic Aid for A1-Protein Intolerant Athletes? Nutrients. 2017;9(2).
- National Health and Medical Research Council. Australian Dietary Guidelines. Canberra: National Health and Medical Research Council; 2013.