Protein: why, when, how and what


What about Protein?

The importance of protein and the question ‘how much protein do I need?’ has been a hotly debated subject for decades. Traditionally scientists have held a view which suggested as long as you meet your RDA for protein adding any extra to your diet would hold no further benefits. However research taken into account since the 1980s shows considerable evidence that the daily protein requirements of an active individual are higher than those that live a more sedentary lifestyle.

Why Do I need Protein?

Proteins are the building blocks of life. They make up part of every structure of tissue and cells in your body, from your muscles and organs to your hair and nails. Protein is needed for the growth, formation and the repair of tissue. This is especially relevant to exercise. When you take part in resistance training for example you make tiny micro tears in the muscle. It is this damage that stimulates and facilitates growth and repair which results in an increase in strength and fitness.

Protein is essential to the production of almost all of the body’s enzymes and some hormones such as adrenaline and insulin. Also, ever useful, protein can also be utilised an as energy source.

Protein as an energy source?

The current recommended protein intake of 0.75g/kg BW/day has been shown to be inadequate for those participating in regular exercise and sport in various studies of both strength and endurance.

More protein is needed to combat the increased breakdown during and immediately after exercise to facilitate repair and growth. Exercise activates an enzyme that oxidises key amino acids in the muscle which are then used as a fuel source. The greater the exercise intensity and duration the more protein will be broken down for fuel.

This is not necessarily a bad thing. To some extent it is unavoidable and testament to your body’s impressive adaptability for sourcing energy from within. However, if your goal is to gain lean muscle mass, or your sport requires lots of muscle and cardiovascular fitness then steps should be taken to reduce this breakdown effect.

Can I minimise protein breakdown?

When your glycogen stores are low protein is broken down in increased quantities. Should you partake in a session that is high intensity and lasting longer than 1 hour protein can make a substantial contribution to energy needs (up to 15%!).

Now, it makes sense of course to start any exercise session with high muscle-glycogen stores so your body is full of usable energy and ready to go. If you do this you will reduce the amount of protein your body contributes to energy during your exercise session. A banana during exercise, or on a long run will also go a long way towards helping.

If you are on a weight/fat loss programme it is important to avoid dramatically reducing your carbohydrate intake. If you do protein will be used as an energy source more regularly for the reasons above. Aim to maintain 60% of your calorie intake from carbs – all calorie cutting needs to be done in proportion with the nutrients you need.

Can protein in your diet help you lose weight?

A study at the University of Illinois suggests that a protein rich diet boosts the weight loss benefits of exercise (Layman et al. 2005). A higher protein intake can offset some of the muscle-wasting effects associated with fat loss and calorie cutting programmes, thus maintaining lean muscle mass and metabolism. This in turn encourages a sustainable long term diet plan. I don’t recommend calorie-cutting FAD diets, as they confuse the body and don’t lend themselves to long term achievable weight loss and change.

Take note that any increase in the protein percentage of your diet needs to be in proportion to your consumption of carbohydrates, fats and minerals! You can’t cut one out to make room for another as they complement each other.

Is the timing of protein intake important?

There is a lot of debate and confusion around the subject of whether it is or isn’t more beneficial to consume protein before, during, or after exercise. Then more specifically whether that should be 1 hour after, or 20 minutes after exercise.

Looking at the facts available, studies have shown that the timing of protein intake does appear to be important. A review of studies (by researchers at McMaster University) concluded that protein should be consumed early in the post-exercise recovery phase. Ideally within the first hour of exercise and combined with carbohydrate in the ratio of 1:4.

Don’t panic if you miss this window though. Studies suggest that muscles are most receptive to amino acid uptake during the first 2 hours post-exercise. Then again everyone is very different and it may extend up to 24 hours post-exercise! Muscle synthesis is taking place at the fastest rate here so it is important to consume protein throughout the day at regular intervals. Eggs and milk for breakfast anyone?!

What sort of Protein is best?

Many studies suggest that high quality milk proteins (e.g. whey) are the best types for post exercise consumption. This will most likely be the basis for the science behind the production of protein supplements. As for the food you eat day to day, good sources of protein come from: lean meat and fish such as chicken breast, cod and mackerel; low fat dairy products and eggs; nuts and seeds such as peanuts and sunflower seeds; pulses such as baked beans, red lentils and chickpeas. Other sources can be Soya and Quorn products.

What about Supplements then?

We will delve into the realms of which supplements are better than others another day. However as food for thought (excuse the pun) it has been found that some sources of protein, such as milk are just as effective as some supplements. It is thought that milk somehow changes the metabolism of proteins in muscle and thus enhances muscle adaptation to exercise.
Can too much Protein be harmful?

As far as is understood the answer is no. You cannot hurt yourself by consuming more protein than your body requires. You may hurt your wallet though! If you are over-using expensive protein supplements then the nitrogen-containing amino group of the protein is converted into urea and passed to the kidneys. This is then excreted as urine. You could quite figuratively be pissing money away!

The remainder is converted into glucose and used for fuel or stored, usually as glycogen. While it is possible it is unlikely that excess protein would be stored as fat.

Protein Pic

Information collected from ‘The Complete Guide to Sports Nutrition’