Sport & Exercise Scientist Jack Wilson covered the importance of carbohydrates in his previous blog and his attention now turns to the second macronutrient that's crucial to the performance of athletes: protein. Jack gives us the lowdown on protein sources, supplements and how much we need...

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Why is protein important for athletes?

Dietary protein provides numerous benefits to overall health, body composition and performance. Once ingested, dietary proteins are broken down into amino acids, the building blocks for tissue growth and repair, as well as the synthesis of things like hormones, enzymes, neurotransmitters and antibodies.

In addition, dietary protein provides several other benefits, including...

  • Maximising how full we feel after a meal. Of the three macronutrients (carbohydrates, proteins and fats), proteins are by far the best at making us feel fuller for longer. If you’re always hungry after a particular meal, a lack of protein is a common culprit. Getting a good amount of protein in each meal is therefore beneficial for managing hunger levels and lessening cravings for potentially unhealthy snacks between meals.
  • Helping to maintain muscle mass during a calorie deficit. When trying to lose weight the aim, in most cases, should be to lose as much of this weight from fat mass as possible, whilst minimising losses in muscle mass. We do this by providing our body with anabolic stimuli, namely resistance training and protein ingestion. High protein intakes can be particularly beneficial under these circumstances, but more on that later.
  • Maximising our response to training. Training and protein ingestion independently benefit muscle protein synthesis. When combined, the two can have additive effects which give us maximal bang for our training buck.
  • Increasing ‘dietary-induced thermogenesis’ (DIT). DIT reflects the number of calories our bodies burn in order to process and digest the foods we eat. Different foods have different DIT values based on their macronutrient composition. Again, of the three macronutrients, protein requires the most calories to process. Thus by swapping your cornflakes in the morning for some eggs, you’ll burn more calories that day.
  • Providing energy for endurance exercise. Carbohydrates and fats are the main fuel sources we use during exercise, but during prolonged endurance events proteins provide a small but meaningful contribution to the total fuel supply.

Sources of protein

In keeping with the habit of eating whole foods instead of processed foods whenever possible, at the Porsche Human Performance Centre we encourage our athletes to get the vast majority of their protein from natural sources. These include:

  • Lean meats – e.g. chicken, beef, lamb, pork, turkey, offal, game and exotic meats (e.g. ostrich, crocodile)
  • Fish – e.g. white fish, tuna, salmon, shellfish etc.
  • Eggs
  • Dairy – e.g. milk, cottage cheese, quark, natural/Greek yogurt (look for ≥10 g protein per 100 g serving)
  • Vegetarian sources* – e.g. tofu, tempeh, soy products

We often use other plant-based protein sources like beans, pulses, legumes, nuts, seeds and certain grains (e.g. quinoa) in conjunction with the foods listed above. Their protein contribution can certainly be beneficial and should not be overlooked. However, in our opinion these foods are often best used to ‘top up’ the protein content of a meal due to their inferior protein density, as opposed to being the stand-alone source.

What about protein supplements?

Whilst it sounds like a bit of a cliché, at PHP we always advocate a ‘food first’ approach to your nutrition strategy. That said, we often recommend protein supplements in recognition of the practical advantages they can provide.

Protein powders are often relatively cheap, convenient and transportable; making them ideal to use when short on time or on the move. They’re also a really useful addition to meals that would otherwise lack sufficient protein, for example porridge or smoothies. Thirdly, they can be particularly beneficial for vegans and vegetarians who might otherwise struggle to hit higher daily protein targets.

We usually recommend a standard whey protein supplement (or a vegan blend for vegans, vegetarians or people who react badly to whey). Like all supplements, always choose reputable brands and look for batch testing certificates (like Informed Sport) for quality assurance.

Also, be sure to check that it’s just a protein supplement you're getting and not a protein-carb mix as taking the latter without noticing will likely cause you to inadvertently consume a lot more carbs than you want/need!

How much protein is enough?

The current recommended daily allowance (RDA) for protein is 0.8 g per kg of body mass. So, a 70 kg person should consume 56g protein per day; roughly a grilled chicken breast and a tin of tuna.  However, at this juncture it’s important to distinguish between what is considered necessary for the average person and what is optimal in the context of daily protein intake, especially for active athletes. (This is, of course, also the case when it comes to the RDA for sodium which is why Precision Hydration exists).

Official RDAs for certain nutrients often refer to the amounts needed to avoid deficiencies, i.e. what’s necessary. Research examining the optimal amount of protein, however, suggests higher amounts (several times the RDA) would be more beneficial for our health, body composition and performance.

The exact amount remains a subject of much debate, but at PHP we typically recommend daily intakes of between 2.2-3.0 g/kg. For our 70 kg individual, this equates to 154-210 g protein – yes, a lot more chicken and tuna!

The higher end of that range should be considered by individuals trying to lose weight. Individuals looking to maintain or gain weight should do fine on the middle-lower end of our recommended range.

To start with, we try to get our athletes to simply get some quality protein in every meal. This is usually sufficient to induce some initial benefits since protein intake is often sub-optimal in most peoples' diets. For athletes aiming for particularly high intakes, we tend to add extra protein feeds to their daily routine in the form of additional meals (normally up to 4-5 meals per day) and/or some protein-dense snacks (e.g. Greek yogurt, pre-prepared meats, biltong, tinned fish, hard boiled eggs, a glass of milk etc).

When should you eat protein?

A basic summary of much of the research in this area is that the ideal approach would be to distribute your total daily protein intake evenly throughout the day. This contrasts with the typical modern Western pattern of getting very little protein at breakfast, a larger but still relatively small amount at lunch, then the majority of daily protein at dinner.

There are specific times when protein ingestion can be particularly advantageous. Consuming some quality protein in your pre and post training meals (1-2 hours pre/post) is beneficial as it stops your body from losing muscle mass and maximises subsequent tissue adaptation and recovery.

There's also growing evidence supporting protein feeds just before bedtime as a way of helping you maintain muscle mass when you sleep. In this context, consuming slow digesting proteins like those found in dairy products might be most effective so think foods like Greek yogurt, milk, cottage cheese, quark, milk etc.

When considering the optimal amount of protein needed per meal, research has often pointed towards a threshold amount that we must exceed in order to significantly stimulate muscle protein synthesis. There's then a dose-response relationship (i.e. more is better) until we achieve intakes of ~30 g per meal. Therefore, this is roughly what we would recommend as the minimum target per meal. Including 1-2 palm-sizes portions of protein-dense foods in every meal (likely equating to 30-60 g protein), including breakfast, will cover your bases here.

References for this blog are listed at the base of this page

Myths about protein

There are some common misconceptions around dietary protein...

  1. "High protein diets can be harmful to health". Especially to the kidneys, which play a big role in processing dietary proteins. To date, there's no evidence that high protein diets harm the kidneys of healthy individuals. Problems only seem to arise in individuals with pre-existing kidney problems, so if you fall in to this category then high protein diets aren’t recommended for you.
  2. "Our bodies can only absorb 30g protein in one sitting". In truth, protein absorption efficiency is likely very high (90-95%) and when you think about it from an evolutionary perspective, our ancestors (living in periods of feast and famine) wouldn’t have done too well if they were limited to 30g protein from each kill. Whilst it’s true that consuming more than 30g per meal might not elicit much further benefit to muscle protein synthesis, it can be beneficial for other things like satiety and it's often necessary when aiming for high daily intakes like those in our recommended range for athletes.

The 5 key things to know about protein

  1. Consume the vast majority of your protein from whole-food (mostly animal) sources including meats, fish, eggs, dairy and certain vegetarian foods.
  2. Distribute your total intake evenly throughout the day. Include 1-2 palm-sized portions of these foods in every meal, especially pre- and post-training meals and potentially pre-sleep.
  3. Consider increasing meal frequency and/or protein-dense snacks when aiming for particularly high daily protein intakes.
  4. Consider protein supplements to fortify meals that would otherwise lack protein, or when whole-food sources might be less convenient.
  5. When altering your protein habits, be mindful of how your body responds and react accordingly. Beneficial effects = keep going, negative or no noticeable effects = alter things and reassess.

Further reading

References

  • Antonio, J., Ellerbroek, A., Silver, T., Vargas, L., Tamayo, A., Buehn, R., & Peacock, C. A. (2016). A High Protein Diet Has No Harmful Effects: A One-Year Crossover Study in Resistance-Trained Males. Journal of Nutrition and Metabolism, 2016, 1-5.
  • Deutz, N. E. P., Ten Have, G. A. M., Soeters, P. B., & Moughan, P. J. (1995). Increased intestinal amino-acid retention from the addition of carbohydrates to a meal. Clinical Nutrition, 14(6), 354-364.
  • Deutz, N. E., & Wolfe, R. R. (2013). Is there a maximal anabolic response to protein intake with a meal?. Clinical Nutrition, 32(2), 309-313.
  • Egan, B. (2016). Protein intake for athletes and active adults: Current concepts and controversies. Nutrition Bulletin, 41(3), 202-213.
  • Helms, E. R., Zinn, C., Rowlands, D. S., & Brown, S. R. (2014). A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. International Journal of Sports Nutrition and Exercise Metabolism, 24, 127-138
  • Moore, D. R., Camera, D. M., Areta, J. L., & Hawley, J. A. (2014). Beyond muscle hypertrophy: why dietary protein is important for endurance athletes. Applied Physiology, Nutrition, and Metabolism, 39(9), 987-997.
  • Murphy, C. H., Hector, A. J., & Phillips, S. M. (2015). Considerations for protein intake in managing weight loss in athletes. European Journal of Sport Science, 15(1), 21-28.
  • Phillips, S. M., & Van Loon, L. J. (2011). "Dietary protein for athletes: from requirements to optimum adaptation." Journal of Sports Sciences, 29 (Suppl. 1), S29-S38.