11 August 2009

Use milk to build muscles

This may come as a surprise to strength-training athletes: you can increase your muscle mass by drinking more milk.


This may come as a surprise to strength-training athletes: you can increase your muscle mass by drinking more milk.

But if you take the following facts into consideration, the above statement makes sense:

  • Athletes can achieve optimal lean body-mass gain by combining appropriate resistance or strength- training (using weights) and a balanced diet.
  • The diet should supply a balanced amount of energy and macronutrients (proteins, carbohydrates and fats) to ensure optimal muscle growth.
  • The combined intake of amino acids (the building blocks of protein) and carbohydrates stimulates net protein synthesis and subsequent muscle growth.
  • Following resistance exercise, the intake of milk (which is a combination of protein and carbohydrates in a natural whole-food matrix) stimulates muscle protein synthesis and provides an alternative to synthetic sports supplements or soy protein.

Strategies to achieve muscle and weight gain
In certain sports disciplines, such as rugby, short-distance running and boxing, a combination of low body-fat levels and increased muscle mass is required if the athlete wants to achieve bursts of energy and rapid recovery.

Athletes can use two main strategies to achieve weight gain:

  • increasing fat mass; or
  • increasing lean mass (this is by far the more preferred weight-gain strategy).

The role of milk
Recent research focused on the muscle amino-acid balance of strength-training athletes and the ingestion of a whole food source (milk) following resistance exercise.

When considering milk as a whole food, four recently published studies have established the positive impact of milk on muscle gain:

  • The consumption of 2% milk, or a milk-based, carbohydrate-protein beverage, immediately following muscle-damaging resistance training helped to preserve more muscle compared to a sports drink or water (Cockburn et al, 2008).
  • Drinking milk ensured the uptake of important amino acids, which are required for net muscle protein synthesis. This suggests that it would be suitable to use milk in the recovery phase, following resistance exercise, and that milk can be used as an alternative to protein sports supplements (Elliot et al, 2006).
  • The consumption of skimmed (fat-free) milk promotes more muscle protein accumulation after resistance exercise than soy-based proteins. The consumption of either milk or soy protein with resistance training promotes muscle-mass maintenance and gains. Thus, the regular consumption of milk proteins after resistance exercise is likely to support the build-up of lean muscle mass (Wilkonson et al, 2007).
  • The regular consumption of fat-free milk after resistance exercise promotes greater lean mass build-up than consumption of soy or carbohydrates in young, novice, male weightlifters during the early stages of resistance training (Hartman et al, 2007).

Nutrition for strength-training athletes
As mentioned above, strength-training athletes require a combination of appropriate strength (resistance) training and a balanced diet to achieve optimal lean body-mass gain.

Resistance training provides the necessary stimulus for muscle growth, while a diet supplying a balanced amount of energy, carbohydrates, protein and fat will supply the athlete with enough energy and nutrients to encourage optimal muscle growth. Table 1 shows an example of the nutritional requirements of a strength-training athlete according to sports nutrition literature.

Table 1: Nutritional requirements of a strength-training athlete (Milk SA, 2009)

Nutrient Recommended daily requirement
Energy Maintain energy intake (kJ) plus 20%*
Carbohydrate 60% of total energy needs

- Normal energy requirements: 1.4 to 1.8g/kg body weight
- Increased energy requirements: 1.8 to 2.0g/kg body weight

Fat 15 to 30% of total energy needs

* Maintenance energy can be calculated for an individual based on his/her weight, length, age and activity level.

Timing is important
The composition and timing of a post-exercise meal is important. Strength-training athletes should start refuelling with carbohydrates and protein soon after training to optimise glycogen recovery and muscle gain.

This should be followed by eating regular small meals to further promote glycogen storage and muscle growth. Carbohydrate intake of 1 gram per kilogram of (current) bodyweight during the first two hours after training is recommended.

An example of the nutritional contribution of 300ml servings of selected dairy products consumed in the first two hours after exercise is shown in Table 2.

Table 2: Post-exercise nutrition – selected dairy beverage examples (/300ml portion)




Fat Carbohydrates (CHO)
  kJ g g g Estimated CHO contribution in recovery period – 70kg athlete*
Full cream milk






Low-fat milk






Low-fat drinking yoghurt






Low-fat flavoured milk






* Example: 70kg athlete aiming to consume 1g carbohydrates per kilogram (current) bodyweight in the first 2 hours after strength-training.
(Nutrient composition provided by Milk SA, 2009)

Dairy beverages can make a significant contribution to the macro-nutrient requirements and the recovery of a strength-training athlete if they're included in the post-exercise meal. Particularly positive results are obtained with drinking yoghurt and flavoured milk.

So, for those athletes who are busy bulking up and want to increase their lean muscles mass, keep in mind that drinking milk after resistance training will promote muscle mass maintenance and gains by promoting an increase in lean mass build-up.

It may be a novel idea that it's not always necessary to splash out on expensive sports supplements, which may contain all kinds of unnecessary and potentially harmful additives, but that drinking milk will satisfy your protein needs and build your muscles. Give it a try – you'll be pleasantly surprised!

(Dr Ingrid van Heerden, DietDoc, August 2009)

Any questions? Ask DietDoc

(Cockburn E et al. 2008. Acute milk-based protein-CHO supplementation attenuates exercise-induced muscle damage. Appl. Physiol. Nutr. Me. (33/4): 775-783; Elliot, TA et al. 2006. Milk ingestion stimulates net muscle protein synthesis following resistance exercise. Med. Sci. Sports Exerc. (38/4): 667-674; Hartman, JW et al. 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. Am. J. Clin. Nutr. (86/2): 373-381; Milk SA 2009. Milk enhances muscle gain for strength-training athletes; Wilkonson SB, et al. 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. Am. J. Clin. Nutr. (85/4): 1031-1040)


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