Why is protein important for athletic performance?

In sports where power and strength are important, athletes/individuals need lean muscle mass which occurs through a process called muscle protein synthesis. In short muscle protein synthesis is the remodelling process of skeletal muscle in response to resistance training leading to muscle growth (hypertrophy).

Protein is therefore an important building block for muscle growth and also for nonmuscular structures like tendons and bone. It is thought that adaptations in muscle occur due to a rise in leucine (an amino acid in protein) which triggers off muscle protein synthesis. Resistance training is the main stimulant for muscle protein synthesis, where one bout of resistance training leads to muscle protein synthesis for up to 24 hours.

Types of Protein

There are different types of protein, which commonly come in the form of supplement bars and powders. Many of these products are successful more so through slick marketing than the ingredients involved, with supplement companies usually promoting the more amino acids and secondary compounds the better the product, which is seldomly the case.

The 3 most common types of protein are whey, casein and soy. When these three are compared against each other it is whey protein that is absorbed the fastest and contains the highest leucine content, the most important amino acid for augmenting muscle protein synthesis.

Timing of Protein Ingestion

TThe timing of protein ingestion is extremely important, because if protein ingestion occurs too close together it creates a blunting effect of muscle protein synthesis. As such, protein ingestion needs to occur equally over a 4-5 meals throughout the day with one pre bedtime meal/shake. The pre bedtime intake is important as muscle protein synthesis diminishes throughout the night and a pre bedtime meal can aid to reduce the drop off. As a guide ingesting protein within 2 hours post exercise and every 3-5 hours is a solid approach.

Protein Dosage

Dairy sources of protein appear to be superior to other sources of protein due to the higher leucine content. However, there are reports of increased muscle protein synthesis with lean meat, casein, soy and egg.

For athletic performance, the optimal dosage is .25-.3g per kg. Pre bedtime meals should contain .6g per kg. While the optimal dose for older adults is around 40g per serve. Dosages greater than 40g have not been shown to augment muscle protein synthesis any further, with any excess protein being oxidized (removed).

Lets talk about diets, as every other week there is a news article talking about the “best” diet for weight loss. There is the high protein diet, the low carbohydrate ketogenic diet, there are experts who say dieting doesn’t work, bloggers spruiking the benefits of the intermittent fasting diet, Instagram influencers telling us the key to weight loss is exercise, and of course it wouldn’t be complete without the latest celebrity diet.

Which Diet Is Best?

With all of this information it is hard to know who is right. In 2014 a meta analysis looked at a variety of diets to see how they compared against each other in relation to weight loss. They compared popular diets like the Atkins, Zone, Weight Watchers and Jenny Craig diets in overweight and obese adults. After 12 months, they found no difference between the diets, with all diets resulting in weight loss.

What about the argument that a well balanced diet is the key? A meta analysis in 2014 compared obese and overweight adults with and without diabetes, who were assigned either a balance diet or a low carbohydrate diet. There were no differences in weight loss between the groups, nor any differences in blood pressure, cholesterol, triglycerides, low-density lipoproteins and high-density lipoproteins (bad and good fats).

Is Exercise The Key To Weightloss?

How about exercise then, with the rise of social media there are plenty of “influencers” promoting their own weight loss exercise regimes, could it be they are right? Unfortunately not, the importance of exercise in weight loss is one of the greatest misconceptions. 100% of our energy intake comes from food, yet only 10-30% can be burned through physical activity. Physical activity is extremely important and is associated with a multitude of health benefits, however for weight loss it is only one piece of the puzzle.

Which Diet Is Best For Me?

About now the question becomes, “if there are no differences between diets and exercise doesn’t contribute greatly to weight loss, then what is the best way forward?” The key to losing weight is adherence. Adhering to a nutritional regime that can be stuck to long term. Low carbohydrate diets and low carbohydrate Mediterranean diets are great for weight loss, especially in obese diabetic individuals, however if it can’t be adhered to long term the weight will return. This behaviour pattern of short term weight loss followed by longer term weight gain is consistent with most weight loss diet research.

If your goal is to lose weight long term, forget the latest fads, ignore social media, and stick to the following key principles.

  • Choose a diet you can adhere to long term
  • Aim for a 100 calorie per day energy deficit
  • Stick to low GI plant based carbohydrates
  • Eat minimally processed foods
  • Include wholegrains
  • Lower your fat intake
  • Choose a form of exercise you will adhere to
  • Join a support group
  • Consider weighing yourself daily