Protein for Sports
- Kayla
- Oct 7, 2019
- 4 min read
Updated: Nov 10, 2019
Protein
Proteins are complex biomolecules consisting of small units called amino acids. Protein in the diet is a relatively minor source of energy. Out of carbohydrates, fat and protein, it should contribute the least calories to the diet.
In the body amino acids can be metabolised during exercise to provide energy directly to the muscle via glucose produced in the liver (gluconeogenesis). However, the consumption of adequate energy (particularly from carbohydrates) to match energy expenditure is important so that amino acids are reserved for protein synthesis and not used for energy.
Functions
Dietary protein acts as a trigger and a substrate for the synthesis of contractile and metabolic proteins when combined with exercise. Muscle protein synthesis (MPS) occurs for at least 24 hours in response to a single session of exercise, with increased sensitivity to the intake of dietary protein over this period. It is important to note that protein alone does not build muscle, but sufficient protein along with resistance type exercise (e.g. lifting weights) will.
Protein Quality
All plant foods contain at least some of each essential amino acid. In general, legumes such as kidney beans tend to be lower in methionine, and some other plant foods such as grains tend to be lower in lysine. But, as long as you are consuming a variety of foods throughout the day (even if exclusively plant-based) you tend to get an adequate amount of all amino acids.
In the 1970s a popular concept was developed, this stated that we should have "complementing proteins" by combining various plant proteins in the same meal to provide all the essential amino acids at one sitting. This concept is now known and has been known for some time to be wrong. It is unnecessary to consume all essential amino acids together in each sitting. The only time it is essential to consume a high-quality protein with all essential amino acids present is immediately after exercise to support Muscle Protein Synthesis (MPS). A plant-based athlete is going to need a good quality protein powder here. Beans just won’t cut it. Protein powders have all the anti-nutrients removed, as it’s just the isolated protein that remains. Because of this, the protein is readily available for your body to digest and utilise.
Leucine appears to be a primary trigger of MPS and plays an important role in promoting recovery and adaptation from exercise. However, Leucine is a limiting amino acid in a number of plant-based proteins, therefore it is important for vegan athletes to be ensure they are getting their protein from a variety of sources.
Some plant foods that are a good source of leucine include: Oats, soya beans, lentils, kidney beans, peanuts, black beans, sunflower seeds, chickpeas and more.
Requirements
The requirement for protein would be to optimise the rate of replacement of proteins being broken down in the body, but also to optimise the adaptive processes. For example, for those wishing to gain lean mass, positive nitrogen balance is the desired goal.
Protein intake for endurance and strength athletes generally ranges from 1.2 to 2.0 g/kg BW/day. Whereas, a normal healthy non-athletic individual has a protein requirement of approximately 0.8g/kg/day. When getting all your protein from plant-based sources, ideally one would opt for the higher end of the spectrum as protein digestibility is lower in plant food due to the presence of anti-nutrients like phytates. Daily protein intakes should be met with a meal plan providing a range of moderate amounts of high-quality protein across the day. High-quality protein is particularly important following a strenuous exercise session.
MPS is optimised in response to exercise by the consumption of high biological value protein, providing ~10 g essential amino acids in the early recovery phase (0 to 1 hours after exercise). This translates to a recommended protein intake of roughly 0.3g/kg bodyweight, which should also be consumed with 1g carbs/kg bodyweight. For most athletes, consuming an adequate amount of carbohydrates straight after exercise will be the more difficult task. The best way to get this is with a quality protein powder served with a high-carb food like toast and fruit.
IMPORTANT NOTE: For some bizarre reason, there is a misconception that athletes should have a protein intake that makes up more than 20% of the diet. Protein intakes should be based on g/kg of bodyweight, not on the percentage of calories provided. Therefore if you are taking in 2g/kg of bodyweight each day, and this amounts to 150g protein. And if you do a calculation and discover that only 15% of your calories are coming from protein because you have a high calorie diet... that is perfectly okay. Increasing the percentage to 20 or more will be of no benefit to you as you are already eating a sufficient amount of protein, and excess protein cannot be stored in the body, therefore it will just be used as energy.
Sources
High Protein Plant-Foods
Protein/100 g
· Pumpkin seeds* (dried, uncooked) 30.2
· Peanut butter* 25g
· Lentils (red, split, uncooked) 24.6
· Black beans (uncooked) 21.6
· Almonds (raw) 21.2
· Tempeh 20.3
· Tofu (calcium set) 17.3
· Oats (rolled) 16.9
· Quinoa (uncooked) 14.1
· Chickpeas 8.4
*nuts and seeds are also a rich source of fat and calories, so don’t overdo it here.
Sample Calculations for protein requirements:
Male. Weight: 85 kg. Goal: Gain lean body mass. Exercise: Olympic Weightlifting
1.7g/kg x 85 kg = 145g protein per day. 25g of this 145g should be consumed immediately after exercise with 85g of carbohydrates.
Information sourced from:
Thomas, D.T., Erdman, K.A. and Burke, L.M., 2016. American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Medicine and science in sports and exercise, 48(3), pp.543-568.
Campbell, B., Kreider, R.B., Ziegenfuss, T., La Bounty, P., Roberts, M., Burke, D., Landis, J., Lopez, H. and Antonio, J., 2007. International Society of Sports Nutrition position stand: protein and exercise. Journal of the International Society of Sports Nutrition, 4(1), p.8.
My personal Sports Nutrition module notes from University College Cork
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