Protein for Sports Performance

According to Class Notes (2015) : 'Proteins are molecules that have many enzymatic and structural functions related to the growth, maintenance and repair.' 

Class Notes (2015) states: 'The goal of dietary protein intake is to contribute the amino acids (EAA’s) necessary to assimilate proteins for skeletal structures and hormones, function as cell membrane receptors and maintain fluid balance.'

Given the definition of what a protein is they are an integral part of any diet. Even more so for a sports performer as proteins primary function is to grow maintain and repair muscle.

Required protein intake is measured by nitrogen balance. For example if the amount of protein intake is positive this is called protein synthesis and if the intake is negative (not enough then this is called protein degradation. 

The video above explains the effects of a positive or negative nitrogen balance. During protein synthesis anabolic processes occur causing muscles to repair and build after exercise. However during protein degradation this is where the muscles have been used during exercise but not repaired by the intake of protein. If you went to the gym and did some strength training but didn't intake protein afterwards the muscles would be damaged and catabolic processes would occur. This shows the importance of protein regardless if your work out or not.

'The RDA (Recommended Daily Allowance for protein in normal sedentary individuals is 0.8g/kgBW (1kg=2.2lbs)' (Class Notes 2015)

However all athletes need an increased amount of protein in their diets compared to sedentary individuals no matter what the sport is. Below is what I researched to show their are different RDA's of protein for contrasting sports performers.

Who? How Much?

RDA for sedentary adult 0.8 g/kg BW/day 
Physically active adult 1.0 g/kg BW/day 
Endurance athlete 1.2 - 1.4 g/kg BW/day 
Strength athlete 1.4 - 1.8 g/kg BW/day 
Adolescent athlete 1.0 - 2.0 g/kg BW/day 
Maximum for adult athletes up to 2.0 g/kg BW/day 

Chowdhury Zaman M.B.B.S., M.S., Dr. Ken Lin, Ph.D. Biochemistry, William O’Neill (2007)


'Protein intake equal to 10-20% of total calories will meet the protein requirements of most athletes. The type of sport and total calorie intakes influence protein requirements. For example, cross country skiing and ice hockey both require a high level of energy intake to meet energy expenditures.' Chowdhury Zaman M.B.B.S., M.S., Dr. Ken Lin, Ph.D. Biochemistry, William O’Neill (2007)

Using the reference theory above I have calculated my protein RDA below:

Sports Performer	Example	Recommended Daily Allowance	My RDA Protein
Sedentary Individual	Exercise less than once a week	0.8 x KgBW	63.2g
Endurance Athlete	Marathon Runner Footballer Basketball player	0.8-1.2 x kgBW	94.8g
Strength Trainer	Power lifter	1.2-1.8 x KgBW	142.2g

If athletes consume 15% of their calories as protein are they getting enough to promote an increase in FFM?

On a day where I complete doerate exercise I require around 3100kcal.

15% of 3100 = 465kcal
465kcal / 4kcal = 116g
116 / 79kg = 1.4g per kg/BW

The idea of consuming 15% of your diet as protein works well as it links in well with the RDA numbers produced earlier. On a moderate exercise day I require 116g of Protein whereas in the study above I varied between 94-142g of protein per day depending on exercise. This number fits in with previous evidence and recommendations therefore it could be a quicker way for an athlete to work out how much protein to intake.

Protein Sources:

Complete Proteins (Contain all 9 essential amino acids EAA's)

Examples: Complete Proteins (Meat, Fish and Diary products)

Incomplete Proteins (Contain some of the 9 essential amino acids)

Examples: (Nuts and Grains)

If an athlete is vegetarian or vegan they can supplement meat and fish with synthesized pure amino acids. They can also use protein shakes to ensure they are receiving all 9 essential amino acids.

Refrences:

Class Notes (2015) Athletic Performance and Protein Intake [Online] Available from: http://vle.chesterfield.ac.uk/course/view.php?id=3196

Christine Dobrowolski (2014) 7.4 Protein: Nitrogen Balance [Online] Available from: https://www.youtube.com/watch?v=9NPGU5XSc54 [Accessed 2015]

Chowdhury Zaman M.B.B.S., M.S., Dr. Ken Lin, Ph.D. Biochemistry, William O’Neill (2007) A Review of the Importance of Amino Acids in Sports Performance [Online] Available from: http://vle.chesterfield.ac.uk/pluginfile.php/283028/mod_resource/content/1/Protein%20%28Amino%20Acids%29%20and%20Sports%20Performance.pdf [Accessed 2015]