BSEMS Autumn 2015 Update Blog

Welcome to the Autumn update blog. Lauren James, our resident Dietitian, thought we could all do with some science behind the use of protein supplementation with exercise. Enjoy:

Are you having too much protein?

Exercise can increase the body’s protein requirements through a few mechanisms:

Protein plays a role by acting as building blocks for muscle growth (hypertrophy) following resistance training

Provides amino acids for muscle repair (turnover) following damage caused by exercise

Provides an additional fuel source for exercise where there is inadequate carbohydrate or fatty acids (we want to try to prevent this however!))

For the general public, doing low to moderate intensity exercise such as walking, you require 0.75 to 1.0 gram of protein per kilo of body weight per day. So, for a 60kg female this would be 45 to 60 grams of protein per day. In food terms, this would be a serve of dairy at breakfast, a serving of ham on a sandwich at lunch and a small piece of meat or chicken at dinner.

For a moderate exerciser who might do 40-60 minutes of exercise on at least 3 days per week, with some of this exercise including resistance training, it is recommended that you have 1.2-1.6 grams of protein per kilo of body weight. For an 80kg male, this would be 96 – 128g per day. In food terms, this would be the equivalent of 2 eggs at breakfast, a latte, a snack of a tub of yoghurt and a small handful of nuts, meat or chicken on a sandwich at lunch and a serve of meat, chicken or fish at dinner. It is interesting to note that someone new to resistance training requires more protein than someone who is a long term (longer than 3 months) weight trainer, this is due to the rapid increase in muscle mass when you first start weight training.

For those preferring endurance activity such as running or cycling at least 3 days per week, it is recommended you consume 1.2 to 1.7g per kilo of body weight. This may surprise some people that endurance activity requires about the same amount of protein as a more strength based trainer. The muscle recovery is quite similar from both types of training.

If you prefer team sports, you also require 1.2- 1.7 grams of protein per kilo of you body weight. The highest protein requirement for a sport is football or power sports. Their protein requirements are from 1.4-1.7g/kg/day due to the high intensity training sessions, resistance training and the games themselves with the hard hits.

Adolescents who are growing rapidly may require up to 2.0 grams per kilo.

It is interesting to note that females actually don’t require the same amount of protein for each of the above sports, even if they are doing the same amount of training. It is recommended that females have approximately 15% less protein for their sport/physical activity that their male counterparts. This is due primarily due to lower levels of muscle mass in females.

The table below outlines the food portions to achieve 10g protein:

Type of Protein SourceAmount required to provide 10g protein
Small eggs2
Milk250mL/1 cup
Cheese40g/ 2 slices
Yoghurt200g/1 tub
Beef, lamb or pork35g cooked weight
Chicken40g cooked weight
Fish or seafood50g cooked weight
Wholemeal bread4 slices
Cooked pasta or rice2 cups
Lentils or beans, legumes1 cup
Baked beans1.5 cups
Tofu or soy meat100g
Soy milk300mL
Nuts & seeds50g
Protein powderVaries, approx. 1 tblsp
Protein bar1 small or ½ large

You can see it is very easy to achieve the required amount of protein per day, even if you are a consistent exerciser. So what happens to the additional protein you may eat? Any unused food, whether it is from protein, carbs or fat will be stored in the fat cell for later use as a fuel. So more is not better in this case!

There is a risk of some people not consuming adequate protein, particularly those following a vegetarian or vegan diet. This is likely due to not consuming large enough serves of beans or tofu. This may lead to inadequate recovery, sore muscles and fatigue.

Striking the right balance in your protein intake may be difficult as protein rich foods are often very satiating and you may find eating additional protein helps manage your appetite. This needs to be weighed up against your individual requirements to ensure the additional protein foods you are consuming are not contributing to an increase in storage of fuel in the fat cells.

An Eat Smart Dietitian can formulate a personalized plan with adequate (but not excessive!) protein so that you get the most out of your work, activity and life! A performance nutrition plan is not just for elite athletes, the everyday active person can also benefit from tailored advice that suits your personal circumstances.