Building Blocks
While carbohydrates and fats serve as primary energy sources, protein plays essential roles in an athlete's body. Its main functions include building and maintaining muscle mass and regulating metabolism. Although these functions are vital, the body does not efficiently store protein, requiring smaller amounts compared to other macronutrients.
Proteins consist of amino acids, the building blocks necessary for various bodily functions. Of the twenty amino acids, nine are deemed "essential," meaning they must be obtained from the diet. The remaining eleven are "nonessential," as the body can produce them. However, certain conditions may increase the body's demand for these nonessential amino acids, requiring additional intake from the diet, referred to as "conditionally essential."
Among amino acids, leucine, isoleucine, and valine (known as branched-chain amino acids or BCAAs) are particularly crucial for muscle tissue maintenance and growth.
Essential Amino Acids | Nonessential Amino Acids |
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*conditionally essential |
The Roles of Protein
Protein serves several essential functions in the body, including muscle tissue formation and repair, enzyme production, and metabolic regulation. While protein can provide energy during exercise, it's not as efficient as carbohydrates or fats in this regard. Additionally, proteins and amino acids play roles in hormone regulation, immune function, and maintaining fluid and acid-base balance.
In the diet, protein is broken down into individual amino acids, which are then utilized as building blocks to meet the body's protein requirements. Since excess protein isn't stored, any leftover amino acids are broken down and mostly eliminated from the body, with some being utilized and the rest excreted in urine.
Protein Sources for Athletes
A balanced athlete's diet includes various sources of protein such as lean meat, poultry, fish, eggs, legumes, and soy products. Dairy products like cottage cheese, milk, and Greek yogurt are also rich in protein. Animal-based proteins contain all nine essential amino acids, making them "complete" proteins, while plant-based proteins may lack certain essential amino acids, rendering them "incomplete." However, soy is an exception, being a complete plant-based protein.
For individuals opting for plant-based protein sources, it's crucial to consume a diverse range of foods to obtain all essential amino acids. Combining complementary foods like grains and legumes, such as rice and beans, ensures the intake of all necessary amino acids. Athletes following vegetarian or vegan diets should be mindful of these combinations and include them regularly in their meals.
Protein Intake and Timing
Recent research on protein has extended beyond determining the ideal quantity of protein intake to investigating the optimal timing of protein consumption.
Research increasingly suggests a link between skipping breakfast and obesity, emphasizing the importance of balanced protein intake throughout the day.
The body's limited capacity to store excess dietary protein for later use means that an imbalanced protein intake fails to adequately support muscle growth and repair. Distributing protein evenly throughout the day is thus recommended to optimize muscle rebuilding and curb appetite. Aim for around 20 grams of protein at breakfast for younger individuals and 30-40 grams for older individuals maximizes muscle rebuilding potential after a prolonged fasting period.
This balanced protein distribution concept not only supports muscle health but also influences various health outcomes, including blood sugar control, calorie intake moderation, and satiety. A 12-week study comparing the effects of a high-protein breakfast versus a normal-protein breakfast in habitual breakfast skippers revealed that consuming a high-protein breakfast, containing 35 grams of protein, prevented fat gain and led to voluntary reductions in daily food intake and hunger, ultimately contributing to improved weight management.
Importance of Protein Quality for Athletes
When discussing the importance of a "protein-packed breakfast" or setting protein recommendations, the quality of protein is paramount. Although there isn't a formal definition of "high-quality" protein, various methods can assess dietary protein quality. Generally, proteins that provide all essential amino acids are considered high quality. These include foods like eggs, fish, beef, poultry, dairy products (such as milk, cottage cheese, Greek yogurt, whey protein, among others), and soy. Of particular significance is the amino acid leucine, which plays a crucial role in protein quality.
Leucine: The Key to Protein's Effectiveness
A significant factor linking the mentioned foods is their rich leucine content. But what exactly is leucine, and why is it crucial?
Leucine is one of the essential amino acids, meaning it must be obtained from dietary sources as the body cannot produce it. Among the nine essential amino acids, leucine is one of the branched-chain amino acids.
Leucine plays a pivotal role in muscle protein synthesis, where its concentration in a protein dictates the optimal protein intake per meal. It acts as the "rate-limiting" amino acid, determining the effectiveness of muscle protein synthesis. Studies suggest that proteins with higher leucine content are more efficient in stimulating muscle protein synthesis, with a proposed "leucine threshold" of 2.2 to 3.0 grams per meal. Falling below this threshold may result in the protein being utilized for energy rather than muscle synthesis, underscoring the importance of quality over quantity.
While protein supplements can provide the recommended leucine intake, real foods also offer ample amounts. Cottage cheese, for instance, stands out as a top source, providing 2.9 grams of leucine per cup (about 28 grams of protein). Other food sources rich in leucine are detailed in the table below.
By prioritizing both the timing and quality of your protein intake, you can effectively support your overall health and fitness goals.
Food (Portion) | Leucine (grams) |
Cottage Cheese (1 cup) | 2.9 |
Chicken Breast (3 oz) | 2.4 |
Ground beef (3 oz) | 2.0 |
Wild Salmon (3 oz) | 1.6 |
Whole egg (1) | 1.2 |
Skim milk (1 cup) | 0.8 |
Translating Research Findings - Protein for Athletes
With so much information on the internet about Protein, research and finding, here's what I recommend as a coach and putting it in practical terms:
1. Emphasize consuming high-quality protein sources in the morning as part of a balanced diet, complementing other food groups.
2. Recommend aiming for a portion of protein equivalent to the size of their palm at each meal, providing around 20 to 30 grams of protein, depending on individual hand size.
3. Encourage reducing protein portions in the evening, as excessive intake during this time may exceed the body's needs.
4. Highlight the importance of carbohydrate intake in influencing protein utilization. Adequate carbohydrate consumption ensures that protein is primarily reserved for its essential functions.
5. Post-workout, prioritize consuming 20-30 grams of protein within 30 to 60 minutes to facilitate muscle repair and glycogen replenishment. Maintain this intake pattern throughout the day for sustained muscle support.
6. Opt for easily digestible post-workout snacks like a egg sandwich or cottage cheese with fresh fruit. For those who struggle with post-workout hunger, liquid options such as fruit and yogurt smoothies, protein shakes, or chocolate milk can provide necessary nutrients for muscle recovery, as demonstrated in research findings.
Recovery Snacks: Winning Combinations of Carbs and Protein |
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Let's Summarise:
- Protein is crucial for muscle formation, maintenance, and metabolic regulation.
- Protein comprises essential and nonessential amino acids, which serve as its building blocks.
- Quality protein sources include lean meat, fish, poultry, dairy, eggs, and legumes, among others.
- Daily protein requirements typically range from 1.2 to 1.7 grams per kilogram of body weight (lean body mass)
- Aim to consume 20-30 grams of high-quality protein with each meal to meet your body's needs effectively.