// Nutrition for muscle mass gains

Many exercisers – predominantly young men trying to ‘get big’ – seek nutritional assistance from the various potions and pills on the market. Protein powders? Creatine supplements? A drink made with moon dust? Nutritionist Dr Rebecca Charlotte Reynolds asks whether these actually work, and looks at ‘normal’ foods and drinks that aid muscle mass gains.

When discussing ‘muscle mass gains’, it’s helpful first of all to define exactly what we mean by the term. We’re talking about skeletal muscle, like the biceps, and we’re talking about increasing the size of the muscle cells, not the number. This process of hypertrophy correlates with an increase in muscle strength. In addition to the aesthetic reasons of many younger male exercisers, muscle hypertrophy is also practiced by athletes, such as sprinters, who need to increase their power output, and by people who want to improve their mobility and quality of life after illness or during ageing.

The resistance/nutrition combo

As health and fitness professionals we know that the single most effective way to increase muscle size is through resistance training. By progressively increasing the work load on a muscle to exceed its pre‐existing capacity for work, the muscle increases its size and therefore its ability to do work. A ‘noticeable’ increase in muscle size takes a minimum of about a month, with an increase in body weight of between two to four kilograms per month being achievable – but only if enough energy and protein are provided in the diet (carbohydrate also helps, but isn’t essential, as we shall see).

So, what constitutes adequate energy and protein? When someone increases the amount of resistance exercise they do, their dietary energy requirements go up because their muscles are using more energy to create the forces to lift weights, as well as to repair and grow. An extra 2,000 to 4,000kJ/day (475 to 950 calories) in food and drink is usually enough, although each client’s requirements will vary depending on the amount of fat stores that can be used to provide the energy, as well as the level of training. If a client isn’t training hard enough to match their increased energy intake, the extra energy will be converted to fat, not muscle. And, providing this extra energy only in the form of dietary fat and carbohydrate will not allow muscles to increase in size – protein is vital, partly because muscles are mostly protein! It’s clear, then, that the body needs both resistance exercise and increased protein and energy to increase muscle mass.

Food Protein content

Cup (250mL) of 0.1 per cent fat milk

9g

Large lean rump steak weighing about 150g

50g (approx)

20 almonds

5g

1 cup (200g) canned and drained chickpeas

13g

100g tofu

12g

1 large egg

6g

100g canned tuna

22g

2 slices of multigrain Burgen bread

13g

Protein-rich ‘normal’ foods

Fortunately, most balanced, omnivorous diets (i.e. when both plants and animals are consumed) provide sufficient protein for muscle mass gains. Dietary protein – like all protein – is made up of amino acid building blocks. Foods that provide higher amounts of protein include: dairy, meat, fish, eggs, bread, certain breakfast cereals, pasta, legumes, rice, tofu, and nuts/seeds. If someone eats enough protein-rich foods – particularly dairy – then there is no need for potions and pills. It is estimated that 1g of protein per kg of bodyweight per day is what is required for a sedentary person. Up to 2g of protein per kg of bodyweight per day is what is required for athletes. So, a dedicated gym‐goer might need 1.5g per kg of bodyweight per day. For an 80kg person, this equates to 120g of protein per day. The chart below shows how this might be achieved;

It is evident that animal foods generally provide higher amounts of protein. To find out how much protein a food contains visit www.calorieking.com.au

Nutrition timing

The timing of resistance training nutrition can also affect increase in muscle size. There is evidence that eating a moderate protein, high carbohydrate snack within two hours both before and after a resistance training session, can aid muscle mass gains (within one hour is preferable). Snacks which fulfil these criteria include: fruit with yoghurt; a bowl of low GI cereal with milk; a grainy bread sandwich with lean ham (preferably free‐range) and salad; homemade smoothies with banana, yoghurt, honey and skimmed milk powder. Note the use here of the word ‘snack’ – eating larger meals near training can cause nausea and cramping.

There’s still a place for supplements

Although it’s clear that those seeking hypertrophy can consume sufficient protein from ‘normal’ foods, protein supplements can help if someone isn’t eating enough total protein or the right type of protein. For example, there is evidence that dairy protein, which is called whey, may be the most effective protein at promoting muscle mass gains, so low fat milk protein shakes/powders/bars may be useful. It should be noted, however, that there is insufficient evidence that amino acid supplements provide any benefits.

Supporting growth with 'ready energy'

Now, we mustn’t forget about carbohydrates. While carbs are not vital for increasing muscle mass, they can make the process feel easier by increasing the intensity and duration of resistance exercise. They do this by providing ‘ready energy’ to muscle cells in the form of glucose – and also result in the production of insulin, a potent growth‐promoting hormone (including promoting the growth of fat tissue!). Low glycemic index (GI) carbohydrates provide energy for longer, so are even more effective at giving the muscle cells some ‘oomph’!

Non-protein supplements

So, what about non-protein supplements, including: creatine, caffeine, HMB, colostrum, nitric oxide, chromium, and hormones like ‘andro’? Supplement marketers are very skilled at using strategies that play on emotions and promote ‘quick fixes’ – just like those who sell weight loss diets! And, like most weight loss diets, most non‐protein supplements are a waste of money. There is only weak evidence for any benefits resulting from HMB and colostrum supplementation, and even weaker evidence for nitric oxide and chromium supplementation.

Two compounds, though, have some evidence supporting their use in promoting muscle mass: creatine and caffeine. Taking creatine supplements (especially in the form of creatine monohydrate) can increase muscle performance, exercise capacity and mass/strength gains. However, the strongest evidence is for improved recovery between repeated bouts of high intensity exercise and performance of high intensity exercise, so unless someone is engaging in hard resistance/power training, these supplements may have limited use. The evidence for direct stimulation of muscle mass is limited, and any initial weight increase (usually of about 1kg) with creatine supplementation is due to fluid retention (creatine is stored in the muscle with water). There is some inconclusive evidence about the adverse effects of creatine supplementation and more long‐term research is needed.

Further reading

For further information visit these web pages:

Caffeine is found in varying amounts in tea, coffee, chocolate, cola drinks, some energy drinks and tablets, and may enhance performance during power exercise of between one and five minutes if consumed before or during exercise. There is inadequate evidence about caffeine benefiting exercise of 10 to 20 seconds in duration (e.g., weightlifting reps), although caffeine here may alter perceptions of fatigue. The dose at which more caffeine doesn’t result in any further benefits is 3mg/kg and there are several side effects that may occur, including anxiety and dehydration. This amount is equivalent to 210mg for a 70kg person – that’s three cups of coffee, two espresso shots or four cans of cola!

Finally, various hormones have been implicated in enhanced exercise performance, e.g., growth hormone and androgens like testosterone and its precursors DHEA‐S (dehydroepiandrostenedione) and androstenedione (‘Andro’). None are recommended for supplementation here, especially for professional athletes.

Understand the limitations

There are limits with using nutrition to increase muscle mass. A client’s genetics will partly determine how effective a training and nutrition program will be, and their intensity of training will affect how easy it is for them to take in enough kJ and protein. Although fitness professionals can offer a degree of guidance when it comes to a client’s nutrient intake, it should be remembered that their area of expertise lies with physical activity, and that specific dietary advice falls under the realm of other professionals, including dietitians and sports dietitans.

COMING SOON: Look out for an upcoming CEC course developed by Rebecca for the Network Nutrition Coach series.

Dr Rebecca Charlotte Reynolds, PhD
Rebecca finished her PhD investigating the effect of the glycemic index on hormones, appetite and acne vulgaris at Sydney University in 2009. She has since worked in community-based obesity prevention at The World Health Organization’s Collaborating Centre on Obesity Prevention, in nutrition education for fitness professionals at Australian Fitness Network, and for public health nutrition students at Deakin University. For more information email rebecca@nutritionundressed.com.au or visit www.nutritionundressed.com.au