Sports Recovery: Why Milk is an Ideal Choice

Optimal nutrition is well recognized as a fundamental focus for athletes’ peak performance. Replacing nutrients and fluid helps to replenish energy stores, promote muscle repair, and rehydrate the body after workouts.1 Milk is an ideal sports recovery beverage because of its unique nutrient package, which includes: carbohydrates, complete protein, electrolytes, and water.1-3

Research shows that both plain and chocolate milk can have benefits compared to other sports drinks.2-5

Homme et femme faisant du jogging à l'extérieur

Key nutrition goals after exercise

There are several key nutrition goals after exercise.1-3 These include:

  • Rehydration with fluid and electrolytes;
  • Replenishing muscle glycogen stores after endurance activities such as: running, swimming and cycling;
  • Repairing muscle tissue damage and optimizing body composition following resistance training such as weightlifting. 

Fluid and nutrient replacement can also help reduce muscle fatigue and soreness after intense workouts. This in turn can help athletes keep up with and maximize their training regimens. 

How milk fulfils sports recovery goals

Research shows that milk’s unique nutrient package makes it an ideal choice as a sports recovery beverage for rehydration, refuelling, and muscle repair.2,3 The specific nutritional requirements will depend on the type of exercise undertaken and the individual goals of the exerciser.2

  • Milk contains energy in the form of carbohydrate (i.e., lactose) to help replenish muscle glycogen stores.
  • Unlike traditional sports drinks, milk is also an excellent source of complete protein with a high concentration of branched-chain amino acids (such as leucine) to support muscle protein synthesis. The 3:1 ratio of casein to whey proteins in milk is ideal because it facilitates slower digestion and absorption leading to sustained elevations in circulating amino acids, the building blocks for muscle repair. 
  • The combination of milk’s high water content along with electrolytes such as calcium, potassium, and sodium, helps to replace the fluids and electrolytes lost through sweating during exercise.
  • Milk also contains other essential vitamins and minerals, many of which are missing in the diet of most Canadians.

In practice

Milk is an ideal sports recovery beverage. The choice of plain milk or chocolate milk will depend on the individual’s exercise and sports recovery goals.

  • Drinking plain milk as a source of complete protein, particularly after exercise, is good for building and repairing muscles. It is also an effective source of hydration.
  • Chocolate milk may only be more advantageous compared to plain milk under specific conditions when additional carbohydrate is needed. For example, chocolate milk is a good option as a recovery beverage after a demanding exercise session that is followed by another demanding exercise session within an 8-hour period. Sessions need to be demanding enough and of sufficient duration to substantially deplete carbohydrate stores. Some examples include: 

- Higher-level athletes who do different or similar types of training sessions throughout the day.

- Training for a triathlon with training sessions in the morning followed by more training sessions in the afternoon.

- Tournament situations with more than one event per day, such as for swimming, soccer, or hockey.

Milk makes sense for rehydration

Studies have found both plain and chocolate milk are effective for restoring fluid balance after exercise. 2,3,6,7 For example, in one randomized controlled trial, healthy young adults remained in net positive fluid balance throughout the recovery period after drinking plain milk; but returned to net negative fluid balance one hour after drinking a sports drink and water.6 Urine output was less after drinking milk compared to the sports drink and water. A review focused on chocolate milk also suggests that it is superior to sports drinks due to lower urine output during recovery.7 

Milk helps build lean muscle mass 

Studies have also shown that drinking plain milk regularly after resistance training can help promote optimal body composition, increasing lean muscle mass and reducing fat mass. For example, men who drank plain milk after weightlifting benefited from greater gains in lean mass (including muscle) and greater reductions in fat mass, over a period of 12 weeks as compared to a soy beverage or a traditional carbohydrate-rich sports drink.8 Women who drank plain milk after heavy whole-body resistance training also benefited from greater muscle mass accretion, strength gains and fat mass loss, over a period of 12 weeks, compared to a carbohydrate-rich drink.9

Milk and Sports Recovery

View the evidence

The overall scientific evidence indicates that both plain milk and chocolate milk may play a beneficial role in the context of sports nutrition. Milk has a number of characteristics, including protein, carbohydrate, water and electrolytes, that make it an effective sports recovery beverage after endurance and resistance exercise. Chocolate milk can help supply additional carbohydrate when that is needed, such as between bouts of high-intensity exercise. Milk is also a cost-effective option compared to other commercially available sports recovery drinks.

Highlights

  • Milk’s overall “nutrient package,” which includes protein, carbohydrate, water, and electrolytes such as sodium and potassium, makes it an ideal choice for rehydration as well as muscle protein synthesis after exercise.
  • Drinking milk after exercise may benefit performance and recovery of muscle function and reduce muscle soreness and tiredness. 
  • Plain milk is superior to soy beverage after resistance training for increasing muscle mass.
  • Chocolate milk may only be more advantageous compared to plain milk when additional carbohydrate is needed (e.g., between bouts of high-intensity exercise). 

General nutrition guidelines 

The Position Paper from the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance provides the following guidelines, with regards to recovery for active adults and competitive athletes:1

1.    Restoring glycogen with carbohydrate is a key recovery goal after exercise. Refuelling is particularly important between carbohydrate-dependent exercise sessions when performance in a second session is a priority.

  • Carbohydrate intake early in the recovery period (~ 1 to 1.2 g/kg/h during the first 4 to 6 hours) can help maximize the effective refuelling time. 

2.    High-quality dietary proteins are effective for skeletal muscle protein synthesis, repair, and maintenance. 

  • Milk-based protein consumed after resistance exercise is effective for increasing muscle strength and leads to favourable changes in body composition. 
  • Dairy proteins appear to be superior to other proteins, largely due to their leucine content and bioavailability of branched-chain amino acids in fluid dairy (i.e., milk). 

3.    Adequate fluid intake is important before, during and after exercise for optimal performance as well as overall health. Both hypohydration and dehydration can increase the perception of effort during exercise and impair performance.

The evidence 

Systematic reviews of resistance and endurance exercise

A 2019 systematic review of 11 randomized controlled trials by Alcantara et al. summarized findings on the effects of plain milk on exercise performance and recovery of muscle function after resistance or high-intensity exercise.2 Studies with flavoured, sweetened, and chocolate milk were excluded. Overall, studies showed either neutral or beneficial effects for several measures. 

  • A number of studies found that milk had beneficial effects on a variety of measures of performance and recovery of muscle function such as reduced losses in peak torque, rate of force development, sprint series and markers of muscle damage.
  • Drinking milk 2 hours before endurance exercise improved performance in a 20km time trial. 
  • Milk reduced muscle soreness and tiredness in some studies.

The authors note that the differences among studies may partially be explained by either an insufficient amount of cow’s milk (i.e., not enough protein and/or leucine) or timing of ingestion. 

A 2018 systematic review and meta-analysis by Amiri et al. examined the efficacy of chocolate milk compared to water or other sports drinks on markers of post-exercise recovery in trained participants or athletes.3 A total of 12 randomized controlled trials were included in this systematic review, and 11 of these were included in the meta-analysis. The authors concluded that chocolate milk provides “similar or superior results when compared to placebo or other recovery drinks.” Subgroup analysis revealed that: 

  • Chocolate milk increased time to exhaustion when compared to placebo beverages and other sports recovery beverages containing carbohydrate, protein, and fat;
  • Chocolate milk reduced ratings of perceived exertion in high-quality studies;
  • Chocolate milk reduced blood lactate levels. This is favourable since lactate may accumulate in the blood when muscle glycogen is depleted, increasing fatigue.

Randomized controlled trials on resistance exercise

In a randomized controlled trial of 20 healthy young women (mean age of 23 years), Josse et al. compared plain fat-free milk to an isoenergetic carbohydrate drink with respect to gains in lean mass and reductions in fat mass following resistance exercise.4 The authors found that consuming milk versus a carbohydrate drink early during the period after heavy, whole-body resistance exercise resulted in greater gains in muscle mass and strength, decreased fat mass, and a possible reduction in bone turnover in women after 12 weeks. They concluded that their findings, which are similar to those in men, indicate that milk is an effective sports recovery drink to support favourable body composition changes in women undertaking resistance training.      

•    There was a greater net gain in lean mass with milk compared to a carbohydrate drink.
•    Fat mass decreased with training in the milk group only.
•    Isotonic strength increased more with milk compared to the carbohydrate drink for some exercises.

Wilkinson et al. examined the effects of consuming soy beverage or plain milk on net muscle protein balance following resistance exercise in 8 healthy young men (mean age 21.6 years).5 In a randomized, crossover design, subjects consumed plain milk or a soy beverage after a single bout of resistance exercise. This study concluded that when consumed after resistance exercised, milk-based proteins promote muscle protein accretion to a greater extent than soy-based protein.

  • Ingestion of both soy beverage and milk resulted in a positive net protein balance.
  • Analysis of area under the net balance curve indicated an overall greater net balance after milk ingestion compared to soy beverage.
  • The fractional synthesis rate in muscle was also greater after milk consumption than after soy beverage consumption.

Similarly, in a randomized controlled study, Hartman et al. aimed to determine the long-term consequences of drinking plain milk or isocaloric soy or carbohydrate drinks on training-induced lean mass accretion.6 Fifty-six healthy young men (18 to 30 years) who trained 5 days/week for 12 weeks were randomly assigned to consume one of three drinks immediately after and again 1 h after resistance exercise. Participants were assigned to one of three groups, including plain fat-free milk (milk group), a fat-free soy beverage (soy group) and a carbohydrate (maltodextrin containing) drink (control group):

  • Type II muscle fibre area increased in all groups with training, but with greater increases in the milk group than in both the soy and control groups;
  • Type I muscle fibre area increased after training only in the milk and soy groups, with the increase in the milk group being greater than that in the control group;
  • DXA-measured fat-free and bone-free mass increased in all groups, with a greater increase in the milk group than in both the soy and carbohydrate drink groups.

Elliot et al. examined the protein metabolic response to whole milk, plain fat-free milk (isocaloric to whole milk) and plain fat-free milk.7 This study included 24 healthy young volunteers who had not participated in regular resistance training for at least 5 years prior to the intervention. In this study, all three milk groups resulted in:

  • An increase of net muscle protein synthesis after resistance exercise;
  • An improvement in protein metabolism with a single portion of milk after resistance exercise. 

Evidence on hydration

A randomized controlled trial by Shirreffs et al. assessed the effectiveness of plain low-fat milk (alone and with an added 20 mmol/L of salt) for restoring fluid balance after exercise compared to a sports drink and water.8 Eleven healthy volunteers (5 males, 6 females: mean age 24 years) took part in this study.

  • Urine output was less after the milk drinks compared to the sports drink and water.
  • Subjects remained in net positive fluid balance throughout the recovery period after drinking the milk drinks but returned to net negative fluid balance 1 h after drinking the sports drink and water.

Several review papers also describe the beneficial role of milk, including chocolate milk, for rehydration.9,10,11 

Potential mechanisms

A 2019 review by James et al. explains how milk’s unique “nutrient package” makes it especially well suited as a recovery drink after exercise.9 Milk’s high-quality protein provides essential amino acids including leucine to support muscle protein synthesis. It also contains energy in the form of carbohydrates as well as many essential vitamins and minerals, including electrolytes such as sodium, important for rehydration. This review also notes that milk is an economical choice compared to other sports beverages.

An earlier review by Roy et al. also describes the key characteristics that make milk an ideal choice as a recovery beverage.10

  • Milk contains carbohydrates (i.e., lactose in amounts similar to those of many commercially available sports drinks).
  • Milk contains casein and whey proteins in a ratio of 3:1, which provides for slower digestion and absorption resulting in sustained elevations of blood amino acid concentrations.
  • Whey proteins also contain a large proportion of branched-chain amino acids, which play an integral role in muscle metabolism and protein synthesis. 
  • Milk also has a high concentration of electrolytes such as calcium, sodium and potassium, which can replace those naturally lost through sweating during exercise.

Conclusions

The overall body of scientific evidence supports the use of plain milk and chocolate milk, as a recovery beverage after resistance and/or endurance exercise. Research suggests that milk may be even more effective than commercially available sports drinks as a rehydration beverage. Milk’s unique nutrient package, including carbohydrate, protein, electrolytes, and water, makes it an ideal choice for rehydration, refuelling and muscle repair and building after workouts. Since the protein in milk helps to promote muscle protein synthesis, milk may also help to improve performance and reduce muscle functional losses, soreness, and tiredness.
 

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