There is no denying that protein is an extremely important substance when it comes to exercise. Skeletal muscles compile approximately 40% of the bodyweight of the average person, and hold about 60% of the bodies protein stores. Given these figures it is no wonder that people in the sports community, and more importantly sports industry, have become obsessed with protein and its necessity for muscle growth and development. Every other page in a fitness magazine bears an advertisement for some form of protein shake and the first thing that greets you when you enter the gym is often a fridge full of several different protein drinks. There is certainly no shortage of pressure or encouragement to indulge in protein supplementation, but is it actually beneficial to recovery and muscle development?
This is a very important and frequently asked question, but sadly the answers given are often uneducated, biased or just plain lies. Most supplement companies will advertise claims that their product will enhance muscle growth, make you bigger and stronger, and is necessary if you want to achieve your goals. The problem is that the statements they make are fairly unregulated. In fact they can pretty much tell you what they want without any repercussions. Rarely will you be able to find any good quality (if any) studies behind these claims, and without evidence they are worthless. Luckily for us there have been scientific studies into the need for protein in relation to exercise, and we will discuss some of the results here.
So why do we need protein?
As I have mentioned previously, the body is unable to store protein to use later. The protein we have is contained in structures such as muscles and tissues such as ligaments and tendons (as well as making up part of every cell in the body). However these structures, once formed, are anything but static. The body is constantly breaking down the proteins in the body and rebuilding them in a process known as turnover. On average we stay the same weight and composition, and all the tissue broken down is replaced by the same amount. Although the average male may be breaking down 280 g of protein per day, he is also forming another 280 g in its place. This process does not happen simultaneously however and sometimes we may be forming more than we break down. This requires us to have extra protein coming in (through food), in order to fill this temporary deficit. On average we require about 40-60 g per day (average sedentary person) for this. In fact the US recommended protein intake for the average individual is about 0.8 g/kg/day.
But what about the exercising individual?
Exercise puts a stress on the body, and can result in breakdown of muscle tissue and formation of more to deal with the increased load. Naturally one would assume that this extra demand will require more protein, and as such the more we can ingest, the bigger and stronger our muscles will become. This is reflected by the American College of Sports Medicine guidelines for athletes which recommends 1.2-1.7 g/kg/day of protein. As you can see this is significantly higher than for the average population. Studies have shown that resistance exercise does result in stimulation of muscle protein synthesis (MPS), and has little effect on breakdown (MPB). One can conclude from this that resistance exercise will result in more muscle being made than is being broken down, resulting in net gain in muscle tissue. This would require external protein to account for this new muscle mass.
But as I mentioned earlier, we already have 60g of protein coming in via the general recommendations. So would this be enough? As we become more accustomed to exercise, we actually become more efficient in our usage of protein. We in effect become better at recycling it and for this reason our protein needs do not necessarily increase as much as you would think given the extra training. However at this point it is important to mention that resistance exercise is not the only important stimulus to MPS. Just ingesting protein (more specifically certain amino acids) itself causes an increase in MPS, even when no resistance training is done before. This is one reason why increasing the amount of protein ingested per day may be beneficial.
So it is probably reasonable to recommend that athletes partaking in resistance exercise should have increased protein consumption when compared to the average population, but the question is how much more? Intake amongst those who train varies tremendously, from 1 g/kg to up to 5 g/kg!!! So where in this spectrum should most people be? It has been shown that for most people partaking in training (this study compared running, rowing, cycling, bodybuilding and gymnastics), 1.25 g/kg provided enough protein for them to be in positive nitrogen balance (i.e. positive muscle balance). Once this amount is surpassed there seems to be no advantage in terms of muscle gain.
So what happens to all this extra protein? Well as we discussed, the body cannot store protein. Once the body has the protein it requires, the rest is immediately oxidized (i.e. burnt for fuel). This happens in the liver in and the protein is essentially converted to sugar, whilst the nitrogen part of it is excreted by the kidneys as urea in the urine. So if you are having lots of excess protein, you are in fact using it to provide energy, so it could contribute to bodyweight.
Is there any harm in taking high doses of protein?
Some people may not be bothered about the extra energy or cost and just want to take as much protein as possible anyway. Very large amounts of protein can have adverse effects on bone and kidney health, but generally intakes below 2.8g/kg/day do not result in these effects. The main harm in having so much protein will be to your wallet!
Does timing of protein make a difference?
This is a very important question, and one to which we have an answer. The greatest effect on MPS is seen when protein is consumed within 1 hour of finishing resistance exercise. More specifically the effect is dose dependent, with the maximum effect being seen with about 20 grams of protein. Any more than this has no extra effect on muscle growth. There is not really any strong evidence for protein ingestion directly before or during resistance exercise having any significant effect. The increased MPS as a result of resistance exercise and protein typically lasts about 4-5 hours (can be more in very strenuous exercise) before returning to baseline.
What is the best form of protein to have?
There are so many different forms of protein out there that it can be hard to know what to take. Egg, whey, soy, wheat? Whey protein is probably the best absorbed of the proteins, and has been shown to possibly prolong the increased period of MPS over others such as soy. It is perfectly reasonable however to have the protein in natural forms such as skimmed milk or meat, as the amount of protein ingested seems to be the most important factor overall (make sure you get your 20 grams).
Should I mix my protein with carbohydrate?
The studies into whether this will increase muscle synthesis further have so far yielded equivocal results and as such there is generally no firm recommended need to take carbohydrate with protein. It may however be beneficial for endurance athletes as it will help to replenish the depleted glycogen stores.
So what conclusions have we drawn as to recommendations for protein intake to maximize muscle development?
Most people partaking in a resistance exercise program will receive adequate protein to achieve their maximal potential if they consume between 1.25 – 1.5 grams of protein per kg bodyweight per day. This protein would be best consumed as separate portions throughout the day and a 20-25g bolus should be consumed as soon as possible after completion of the resistance training session. The protein bolus may be best take in the form of whey protein, but as long as the full amount is consumed, it probably isn’t too important what food you get the protein from.
Feel free to go out there and buy protein shakes, but if you can’t readily afford them then don’t worry, as you will likely achieve the same results from skimmed milk and good foods (meat such as lean beef). There is never any need to have more than 25 g of protein in any one serving, and any extra will just be immediately burnt for fuel and will NOT go towards any muscle development. Don’t fall for the products offering 60g per bottle, and if you do then just have 1/3rd after each workout and save your money.
Also be wary of all the ‘amazing’ formulas of protein out there. In general whey protein is all much the same and is fairly cheap to produce. I have spoken to insiders in the industry and was amazed to discover the mark up on these products (sometimes the packaging is more expensive for them to produce than the product). You are best off buying cheaper protein in large bulk sachets as opposed to getting the ridiculously priced tubs off the store shelves.
If you train smart and follow the above advice I can guarantee you will achieve the same results as someone who spends hundreds of dollars on large amounts of protein supplements and spends most the day in colonic distress (you will know what I mean if you have ever spent time around someone taking large amounts of protein powder).
Go ahead and give it a try.