'); } };
Recovery Tip

Did you know that your core muscles, which are the deepest layer of your tummy muscles, should work at all times to brace and protect your back? These muscles switch off due to pain and it takes 50,000 repetitions before they work automatically again to protect your back!

Get In Touch

76 Commercial Road (Function Well Gym) Newstead Q 4006

Phone: 0423 687 440

« What happens when you crack your knuckles? | Main | Pilates »
Wednesday
Oct282015

Nutrition for Building Muscle

Many people want to grow their muscles to look and feel good, and have heard that protein is a key to that, but all the advice about when to take protein supplements, where to get the protein from, how much and how effective it is can be very confusing. Do you have questions about protein supplementation for your exercise program? Read on!

 

Image retrieved from http://www.essence.com/sites/default/files/images/2014/06/23/strong-muscles_400x295_23.jpg on 28/10/2015

A recent article from the journal ‘Frontiers in Physiology’ has discussed the current research surrounding protein supplementation and resistance exercise (RE) in regards to muscle hypertrophy (making muscles bigger).  You can find the original article here:  http://journal.frontiersin.org/article/10.3389/fphys.2015.00245/full[1]

***

Firstly, a little about protein. Protein is constantly turning over in the body. There is always muscle protein synthesis (MPS) and muscle protein breakdown (MPB), but it’s the rates at which these occur that are important. If your MPS is higher than your MPB you’ll have overall growth, and inversely if the breakdown is higher than synthesis you’ll have muscle shrinkage.

When humans rest, the net muscle protein turnover is in the red – we tend to decrease our muscle mass when we’re laying around doing nothing. That’s why it’s so important to remain active!

Research also shows that supplemental protein increases muscle protein synthesis (MPS) to bring the net rate of protein turnover into a positive overall state. Resistance training also brings about a positive turnover state (more so than protein), and that when the two are combined the effect is greatest.

 

DOSAGE How much protein should I take?

Combining the results of many studies, researchers have shown that the optimal amount of protein seems to equal about 0.4g of protein for every kg of lean muscle mass or body weight, per meal. This is a moderate to high dose.

0.4g/kg/meal

However, researchers have also found that the amount of protein you ingest doesn’t seem to matter after approximately 20g per meal. They hypothesise that muscles get ‘full’ and seem to reject what it doesn’t need. Any extra protein that isn’t used for muscle repair/growth is ‘burned’ like calories, turned into urea and excreted in urine.

Other studies show that high to very high doses of protein can both stimulate protein synthesis (MPS) and suppress protein breakdown (MPB). However, the effect of this suppression for breakdown in skeletal muscle is very small and it is likely that the overall drop in MPB is due to suppression in non-muscle tissues. To avoid this, the authors recommend that you stick to a moderate to high (~20g) dose to avoid messing with the other body systems.

 

TIMING When do I take my protein?

Resistance exercise (RE) alone has been shown to increase muscle protein synthesis (MPS) in the first 24 hours after exercises. This is called the ‘anabolic window’, and you may have heard that term before. This is the same in first-time gym goers and veteran exercisers. It doesn’t seem to change.

We know that RE sensitizes muscles to protein. Muscles get better at using protein to build themselves up with practice (training). But should we stimulate this with protein before, during or after RE?

Researchers have shown that the effects of taking protein differ for these different time periods. If protein is taken before or during exercise, the muscles get ‘full’ quicker because the protein stores haven’t been used up as much rather than if the exercise was complete, ‘emptying’ the muscle. Therefore, protein uptake for an increase in MPS seems to be greatest post-RE.

A meta-analysis (a study looking at lots of studies combined) seems to show that protein is most effective if it’s taken immediately after exercise, rather than a few hours later, if you’re looking for big muscles. However, the effect was small when compared to the amount of protein taken (the amount is more important than when you take it).  The authors of that study suggested that in the period immediately post-exercise, the three Rs (3Rs) are most important: Rehydrate (fluids), Refuel (carbohydrates) and Repair (protein).

But what about taking all my protein at once, rather than lots of little bits through the day? A few studies have shown that a large dose is better, and others have shown medium-sized doses (“intermediate”) or smaller doses over a longer period (“pulsed”) are superior. However, the authors of this review suggest an intermediate approach to keep muscles topped up with protein, to maximise the “muscle fullness” effect without going over and metabolising protein into urea.

 

Image retrieved from http://gymgeek.com/wp-content/uploads/2014/09/drinking-protein-shake.jpg on the 28/10/2015

 

Sleep

What about during the night? Sleeping for eight hours induces a state of relative fasting. It’s why we’re so hungry for breakfast in the mornings! We’ve spent all night regenerating and repairing, and our bodies are looking for some more ingredients for those processes.

A recent study showed that young men who took drank a protein shake just before bed had better muscle protein synthesis during the night, than a group who didn’t get a shake. However, the limitation to this study is that the men who didn’t get a night-time dose of protein didn’t get that dose at all; the men who were getting the before-bed dose were getting more protein than the control group, so it’s difficult to say for sure whether it was the extra protein or the time it was taken that made MPS higher.

A second limitation with this study is that the amount of protein was given didn’t even come close to the amount recommended for muscle hypertrophy (growth), so it’s difficult to say if the effect would have been better if that was the case. In addition, another meta-analysis showed that the effect of protein on hypertrophy was pretty small (lots of protein only means a little more muscle bulk) so it’s pretty impressive that the before-bed protein dose showed such great results.

 

TYPE Where do I get my protein from?

There are three main sources of protein supplements: soy (from soya beans), casein (from milk) and whey (a by-product of making cheese from milk).  Soy proteins are often used as a replacement for animal proteins in vegans, because it’s 100% plant-based and there is no chance of there being lactose in it for those who are intolerant. However whey and casein seem to be most popular in those without dietary restrictions.

There are benefits and downfalls to each type of protein. They all serve a purpose. We’ve tried to summarise the findings in this table[2] [3][4].

 

Soy

Whey

Casein

Source

Soya beans

By-product of turning milk into cheese, concentrated and dried out

Milk

Timing

Slow acting –
2-3 hours

Very fast  –
20 mins

Slow acting –
3-4 hours

Peak

Very low

High

Low

Pros

Great for vegans and lactose intolerant

Increases muscle protein synthesis

Decreases muscle protein breakdown

Cons

More readily ‘burned’ like calories, instead of being used as food for muscles  

Contains lactose

Contains lactose

Advice

Consume in moderation

Consume immediately after RE

Consume within the anabolic window (3 hours)

 

Each type of protein has it’s own benefits and pitfalls. It seems a combination of the two or more is best for growing big muscles. Don't forget that lean red meat, poultry and fish are exellent dietary sources of protein as well! 

 

CARBOHYDRATES AFTER EXERCISE Should I mix my protein with carbs?

The idea behind adding carbohydrates to protein intake post-RE is to boost insulin production. Insulin is the hormone released by the pancreas, which regulates the uptake of glucose (energy) from the blood into the cells of the body. Glucose is needed in skeletal muscle and fat stores to break down what they’re holding for energy.

Studies show that ingesting carbohydrates stimulates more insulin to be released, than with just ingesting protein. In addition, insulin and protein together stimulate MPS and slightly decrease MPB. However, the MPS increase isn’t as strong if this is post RE.

We know from previous research that ingesting carbs after a workout helps to attenuate muscle breakdown, because we’re giving the body a preferential source of energy. But carbs don’t boost MPS like protein does. So adding carbs to protein intake after exercise doesn’t increase synthesis, but it can help to negate the effects of muscle breakdown (as long as protein intake is adequate) meaning the overall turnover rate of muscle could potentially be more positive. Not much insulin is needed to reach optimal levels of MPS, and this can be achieved with adequate protein intake. At this point in time, carbs post RE are recommended for replenishing glycogen (energy) stores, but the authors of this paper have concluded that there are not enough strong experimental studies to definitively say that carbohydrates significantly impact the overall rate of turnover for muscle.

 

Image retrieved from http://www.muscleandfitness.com/sites/muscleandfitness.com/files/chicken_2_0.jpg on 28/10/2015

TRAINING STATUS Does protein get more/less effective if I’m a gym regular?

When compared to untrained participants, trained individuals had lower peaks of MPS and MPB, resulting in less overall muscle turnover. A study in 2008 had participants only train one leg, using the other leg as the rested ‘control group’. After 8 weeks of training one leg, a short burst of exercise produced a longer MPS response in the untrained leg. This suggested that training negated the length of time that protein synthesis was stimulated for, rather than the peak of the stimulation. Other similar study protocols have produced similar results, suggesting that the training effect shows efficiency of the protein synthesis rather than a second dampening force coming into play. However, the authors refer to Damas et al, 2015[5] for their comprehensive review of the effects of training on MPS post-RE.

Summarized: there is quite a lot of evidence to show that protein improves MPS after RE, but there isn’t so much showing how that changes for individuals who are trained. There is a little bit of evidence to suggest that intensely training athletes might benefit from high doses of protein for their immune system function or to gain weight for weigh-classed sports (e.g. boxing, martial arts, etc.).

As mentioned before, the response of stimulating protein synthesis seems to reach a maximum at about ~0.25g/kg (usually about 20g total) in both trained and untrained individuals. Whether this holds true for whole body RE, remains to be seen. The authors of this paper refer two comprehensive reviews on this topic[6]. They suggest that athletes who perform a majority of their exercise as RE may benefit from higher protein doses, in the range of 1.3-1.8g/kg/day. They caution though that a good training regime is often a mixed one and so they refer back to the ‘3R’ rule discussed earlier.

 

RESISTANCE EXERCISE How should I train?

Previous research has already established that resistance exercise has the greatest impacts on MPS and overall muscle turnover. However, the way in which RE training is carried out can impact the size of that effect.

In a study of trained men who received whey protein post RE, those who lifted weight for longer (12 seconds per rep) had better MPS than those who lifted the same weight for shorter times (2 seconds per rep). Muscle electromyography (measuring the amount of electrical activity in a muscle) showed that those who were in the long-lift group had more muscle activity and it is assumed higher levels of fatigue. The theory is that with increase time under tension, more motor units were recruited and therefore higher amounts of protein synthesis were needed post RE.

The authors of this study recommend that weights should be lifted until contractile failure is reached – not just fatigued (the inability to produce maximal force), to produce muscle growth.

Let’s say you have 100 motor units in a muscle. To lift a weight with that muscle, you might need 10 motor units worth of strength. If you hold that weight for a long time or do a lot of repetitions, those 10 units are going to run out of energy and fail. However, the muscle overall won’t fail, because another 10 units will be recruited to power the holding of the weight.

When heavier weights are lifted, more units are required. When they’re held for long periods, they fatigue more easily. Therefore, the authors of this article have suggested using increased time under tension and high loads (70% of one repetition maximum weight) to produce enough contractile failure to promote muscle growth.

However – the authors also note that low-load and high-load RE has similar effects on MPS. If this is the case, is high-load RE really that much better than low-load? More research is needed to find a definitive answer.

There are many meta-analyses (similar to reviews, this study type collates the data from many different smaller studies to analyse the overall effect) are in agreement when it comes to RE. They suggest that the effects of exercise volume (load (kg) x sets x reps) and the frequency (number of sessions in a week) are the most important variables for building muscle. There are many other factors that can influence building muscle, but the authors of this article believe that these co-variables can be controlled for and positively influenced by working to contractile failure.

 

Image retrieved from http://www.diyhealth.com/wp-content/uploads/2012/07/resistance_exercise_image_title_hcumj.jpg on the 28/10/2015

CONCLUSION

Protein consumption is an integral part of a balanced diet. It allows many essential processes to occur in the body for healing and general wellbeing, including the maintenance of muscular health. Protein can come from various sources, and should be consumed as according to the weight of lean muscle mass in your body, shortly after exercising. For a well-rounded approach, this post-exercise nutrition should be combined with plenty of fluids and some carbohydrates to restore the energy depleted by the exercise undertaken.


[1] Morton, McGlory & Phillips. 2015. Nutritional interventions to augment resistance-training induced  skeletal muscle hypertrophy. Frontiers in Physiology. http://dx.doi.org/10.3389/fphys.2015.00245

[2] Eric Satterwhite, 11 September 2015. Should I take casein or why protein? Bodybuilding.com http://www.bodybuilding.com/fun/satternorton.htm

[3] Locke Hughes, 30 May 2013. Get the scoop on protein powders. Shape Magazine.  http://www.shape.com/blogs/fit-foodies/get-scoop-protein-powders

[4] Bos et al, May 2003. Postprandial kinetics of dietary amino acids are the main determinant of their metabolism after Soy or Milk protein ingestion in humans. The Journal of Nutrition. 133 (5), 1308-1315.  Retrieved from http://jn.nutrition.org/content/133/5/1308.long

[5] Damas, F., Phillips, S., Vechin, F. C., and Ugrinowitsch, C. (2015). A review of resistance training-induced changes in skeletal muscle protein synthesis and their contribution to hypertrophy. Sports. Med. 45, 801–807. doi: 10.1007/s40279-015-0320-0

[6] Phillips, S. M., and van Loon, L. J. C. (2011). Dietary protein for athletes: from requirements to optimum adaptation. J. Sports Sci. 29, S29–S38. doi: 10.1080/02640414.2011.619204
and
Phillips, S. M., and Winett, R. A. (2010). Uncomplicated resistance training and health-related outcomes: evidence for a public health mandate. Curr. Sports Med. Rep. 9, 208–213. doi: 10.1249/JSR.0b013e3181e7da73