Protein Requirements for the Physically Active
It is widely recognized that athletes involved in intense physical training have increased protein requirements.
The new US government guidelines for preventing adult weight gain emphasize getting at least 60 minutes of moderate to vigorous physical activity on most days of the week. For those who have lost weight and are
working to maintain it, the recommendation increases to 60-90 minutes most days of the week. For most Americans, this represents a substantial increase in physical activity. Because exercise increases protein requirements (to support amplified enzyme activity and accelerated tissue growth and repair), many researchers question whether the current recommendation of 0.8 grams of protein per kg body weight per day for adults is adequate for individuals engaged in regular physical activity.
In general, the protein requirement for physically active individuals is not greatly increased above that of the general population.
However, it is widely recognized that for individuals engaging in strenuous endurance or resistance training, protein requirements are increased. The recommended protein intakes for those engaging in endurance and resistance training are 1.2-1.4 grams per kg and 1.6-1.7 grams per kg body weight per day, respectively.
If total calorie intake is sufficient to maintain energy balance (i.e. if energy consumed is sufficient to maintain body weight), these increased protein needs are usually adequately met by dietary intake alone. Protein and amino acid supplementation is rarely necessary and can even be harmful under certain circumstances.
supplemental amino acids taken in excess can interfere with the absorption of other essential amino acids. In addition, replacing protein- and nutrient-rich foods with protein and amino acid supplements can result in nutrient deficiencies including iron, niacin, and thiamine.
Is egg protein all it’s cracked up to be?
Biological Value of Egg Protein
Eggs have the highest biological value (BV) of any food protein, which means that the amino acids found in eggs are converted into body tissue more efficiently than any other known dietary protein.
Egg protein (along with milk and soy protein) possesses the highest possible Protein Digestibility Corrected Amino Acid Score (PDCAAS), the most commonly used measure of protein quality.
One large egg contains about 6 g of high-quality protein, which makes it an ideally packaged
amino acid component for refueling after exercise.
What’s the skinny on protein?
Benefits of Protein Intake During Weight Loss
Research suggests that diets moderate in animal protein and lower in carbohydrates can help dieters maintain muscle mass during weight loss, thus improving body composition. Individuals increasing physical activity as part of a weight loss program likely have increased protein needs relative to total energy consumption.
By increasing the percentage of energy from protein, additional amino acid substrates are made available for building lean tissue while maintaining a negative energy balance.
Layman et al. demonstrated that overweight women consuming a diet moderate in protein and lower in carbohydrates lost more body fat and tended to conserve more lean mass than women consuming a high-carbohydrate diet.
Because lean body mass is the single most important contributor to resting metabolic rate, loss of adipose tissue
and conservation of muscle mass during periods of weight loss is critically important.
Layman suggested that perhaps >1.5 grams of protein per kg body weight should be the goal intake for individuals who are restricting calories for weight loss.
Animal vs. Plant Protein
Eggs are a good source of high-quality protein for individuals who are increasing their physical activity.
Recent studies have demonstrated that compared to vegetable protein diets, animal protein-based diets result in increased net protein synthesis and greater gains in fat-free mass and skeletal muscle mass with resistance training.
This is of particular importance for individuals striving to build or maintain muscle mass. Research also suggests that diets higher in animal protein and lower in carbohydrates can help dieters maintain muscle mass during weight loss, thus improving body composition.
This is of great importance since lean body mass is the single most important determinant of resting energy expenditure.