The Power of Protein
Protein has essential roles in the body and is a nutrient that is found in many animal and plant foods. Dietary protein has two possible fates – it can either be used in growth and repair (e.g. muscle, haemoglobin or antibodies) or burned for energy like carbohydrate and fat. About 15% of body weight is made up of protein, and most of this is found in skeletal muscle, which explains the importance of protein for rugby players. The protein we eat is made up of 20 amino acids (building blocks); the process of digestion breaks down dietary protein into its amino acids, which are then absorbed and reassembled to make various kinds of human protein such as muscle, connective tissue and proteins for the immune system.
Protein activity in the body is in a constant state of change; when dietary protein is insufficient, muscle protein can be broken down to provide amino acids for essential body functions such as immune function. This explains why muscle mass is often lost during times of stress, disease or poor nutrition. On the other hand, when dietary protein is in plentiful supply, muscle mass can be maintained or increased.
Do rugby players need more protein?
In a word, yes. Muscles generate strength and power and strength athletes benefit from maximizing muscle mass. However, it is not as simple as just loading up on protein foods or supplements without considering the diet as a whole. Research has shown that even though protein requirements of rugby players are higher than those of inactive people, there is a limit to the amount of protein that the body can use to increase muscle strength – amounts above about 1.8g/kg body weight will generally be stored as fat. What is more important is the timing of protein intake, that is, when protein is eaten in relation to your training schedules.
Timing of intake straight after hard training is when muscle protein synthesis is increased. Therefore it is important that the right raw materials are available to maximize this. However increasing protein intake at the expense of carbohydrate is a bad strategy for players in heavy training, because without sufficient carbohydrate, the muscle glycogen stores cannot be refuelled and energy available for the next exercise session will suffer. So the ideal recipe is to take both carbohydrate and protein straight after hard sessions, to maximize muscle conditioning and start refuelling. In addition to this plan, players should include protein at all other meal times to ensure a steady supply of amino acids to body cells.
How much do you need?
Multiply your body weight (in kilos) by 1.4. This will give you a guide to how many grams of protein you should aim for while in hard training.
For example:
Your weight = 75kg
Your daily protein goal = 105g
Look at the tables below to add up how you get on with your protein intake.
Ready Reckoner of protein foods
Food portions containing approximately 20g of animal protein
| Animal source | Approx weight gr. | Approx weight oz. | Calories | Handy measure |
| Beef, lamb, pork | 75g | 3oz | 115 | 2 medium slices |
| Turkey, chicken | 75g | 3oz | 105 | 1 small fillet |
| Grilled liver | 100g | 4oz | 190 | 2 tablespoons |
| Grilled fish | 100g | 4oz | 95 | 1 small fillet |
| Grilled fish fingers | 100g | 4oz | 200 | 6 fish fingers |
| Salmon in brine | 100g | 4oz | 165 | 1 small tin |
| Tuna in brine | 100g | 4oz | 100 | 1 small tin |
| Prawns | 100g | 4oz | 105 | 2 tablespoons |
| Eggs | – | – | 240 | 3 medium size |
| Cheddar cheese | 75g | 3oz | 300 | 2 matchbox size pieces |
| Edam cheese | 75g | 3oz | 230 | 2 matchbox size pieces |
| Cottage cheese | 150g | 3oz | 150 | 4 tablespoons |
| Yogurt, low fat | 500g | 20oz | 450 | 4 cartons |
Food portions containing approximately 10g of vegetable protein
| Vegetable source | Approx weight gr. | Approx weight oz. | Calories | Handy measure |
| Nuts eg peanuts, cashews | 50g | 2oz | 295 | 1 medium packet |
| Seeds eg sunflower, sesame | 50g | 2oz | 290 | 4 tablespoons |
| Baked beans | 200g | 8oz | 160 | 4 tablespoons |
| Kidney beans/split peas/lentils | 150g | 6oz | 150 | 5 tablespoons cooked |
| Tofu (soya bean curd) | 125g | 5oz | 90 | packet |
| Soya milk | 350ml | – | 110 | approx 2/3 pint |
| Peanut butter | 50g | 2oz | 310 | 1 tablespoons |
| Bread | 125g | 5oz | 270 | 4 large slices |
| Pasta eg spaghetti | 250g | 9oz | 260 | 8 tablespoons cooked |
| Noodles | 450g | 16oz | 280 | 12 tablespoons cooked |
| Rice | 450g | 16oz | 555 | 12 tablespoons cooked |
| Potatoes | 600g | 21oz | 480 | 8 medium |
| Cornflakes | 125g | 5oz | 450 | 2 large bowls |
| Weetabix | 100g | 4oz | 340 | 5 weetabix |
| Digestive biscuits | 100g | 4oz | 700 | 9 biscuits |
Type of protein
There is much debate on what the best type of protein is. Whey protein and casein are the two major types of protein found in milk and are often the ones used in protein supplements. All animal protein (from milk, eggs, meat, fish and poultry) provides the highest quality rating of food sources. However many plant and cereal foods (bread, cereals, peas, beans, pulses, nuts) also contain significant amounts of protein but need to be combined to produce the same quality as animal sources. A food-based approach to meeting protein requirements should be the focus for all rugby players.
Protein supplements
These are popular with players trying to increase muscle size. Whereas it is accepted that players need more protein than the general public, there is no evidence that supplements offer advantages over dietary sources of protein. The mistake players often make is to take a protein supplement at the expense of carbohydrate straight after training; what is needed at this time is both protein and carbohydrate. This should be taken as ordinary food and fluids.
Are very high protein intakes harmful?
There is not much evidence to show that high protein intakes are harmful, but there are concerns about the effects they can have on hydration and bone health. Very high protein intakes increase water and calcium loss due to the increased excretion of protein waste products through the kidneys. Often high protein intakes result in players not consuming enough carbohydrate foods to support their fuel needs for intensive training.
Source: IRFU
