Nutrition for Health and Performance – Part 2 – Macronutrients – Protein

Macronutrients are nutrients which are required in large concentrations in one’s diet, there are three macronutrients:

· Proteins

· Carbohydrates

· Lipids or Fats

This week we will cover protein.

When one thinks about protein, muscle is the first thing that springs to mind, that is because most of the protein in the human body is in fact in the form of skeletal muscle, bone tissue and organs, however these tissues are majority water with various portions of proteins.

Power and strength athletes are particularly interested in protein, its function and the role it has in the diet.

Proteins like Carbohydrates are made up of carbon, hydrogen and oxygen, however unlike carbohydrates and fats, protein contains nitrogen as well. The proteins within the body are made up 20 amino acids, majority of these amino acids can be synthesized by the body and are termed non-essential amino acids, and these do not need to be included in the diet.

There are however 9 amino acids which cannot be synthesized by the body , hence being referred to as essential amino acids which need to be supplied via ones diet.

The amino acid content within the proteins affects its ability to promote both growth and tissue repair, thus protein quality is highly important.

The high quality proteins include red meat, fish, eggs and poultry, low quality proteins are those which lack in one or more essential amino acid such as grains, beans and vegetables. This is where vegans experience complications, as plant proteins are referred to as low quality proteins, therefore to obtain the required daily protein wide variety of plant foods must be consumed to ensure that all the necessary amino acids are taken in.

In athletes the protein requirement is elevated, both endurance and resistance training athletes, in the endurance athletes, the increased requirement is due to tissue repair requirement and in the resistance athletes also require more protein to fuel tissue repair as well as to ensure a positive nitrogen balance to maximize hypertrophy.

Athlete Requirements:

Research has shown that the daily protein requirements for aerobic athletes is 0.8g/kg of Body weight and can reach up to 1.4g/kg of body weight , activity dependant.

Strength and resistance athletes have a requirement of 1.7 g/kg of body weight.

However because most individuals do not fall into one of these training groups , a general requirement for a broad spectrum of athletes has been developed , 1.50 – 2.0g/kg body weight, will supply the body with adequate amounts, assuming that at least 65% of the protein is of a high biological value, therefore vegans may require in excess of 2.0g/kg body weight.

There have been some concern for negative effect of an intake of protein in excess of 0.8g/kg body weight, but these are unsubstantiated, specifically in the healthy individual as the excess protein is broken down and the nitrogen is expelled as urea in ones urine and the ketoacids are used in one of two paths, as a direct energy source or converted in carbohydrates via glucogenisis.

Reference : Essentials of Strength Training and Conditioning, 3rd Edition. T.R. Beachle & R.W. Earle (2008)

Wade Botha

Bachelor of Sport Science

HONS Exercise Science 2010 UKZN

NUTRITION FOR HEALTH AND PERFORMANCE – Part 1 General Nutrition and the Food Pyramid

Nutrition is one of the most important aspects of general well being and performance in humans, food fuels the human body for exercise and other daily activities, over the next few weeks I will be running a series of posts on nutrition, and particularly nutrition for performance.

Good nutrition is vital to athletes who are looking to improve their performance, diet is not independently responsible for increases in aerobic ability, strength, explosive ability or power, however a good diet allows for individuals to recover faster, perform and train more optimally.

There is much confusion whether or not there is a specific diet to be followed by athletes on a broad spectrum, should it be majority carbohydrates or more of a protein based diet? The truth is that each diet should be individualised to the athlete and his or her goals, there is no one diet for all.

The diet of the average Joe will differ significantly to that of a high performance athlete.

The key factors to be taken into account when putting together a diet for a specific athlete include: age, sex, and genetics, body size, duration, intensity, frequency as well as environmental training conditions.

The Food Guide Pyramid, developed by the U.S Department of agriculture breaks the food groups down in 5 major groups which are required daily for good health.

1. Grains : whole grain cereals, bread, crackers, rice and pasta

2. Vegetables: Fresh, dried , canned or frozen

3. Fruits: Fresh, dried , canned or frozen

4. Dairy: Milk, yogurt, cheese

5. Meat and Beans: Red and white

There is one other group known as Oils, this is not a good food group, although it provides the body with Vitamin E as well as essential fatty acids. This group if combined with the other 5 groups can provide the needed calories for those athletes who require a high caloric daily intake.

Although it is not a “good” food group it is important that it is not completely left out of the diet, but it must be consumed in moderation to avoid complications.

It is important to have a good balance and variety within each of the food groups, i.e. it is more beneficial to mix your fruits up rather than eating just oranges.

Fruit, Vegetables and Grains provide the body with carbohydrates they also serve as a source of dietary fibre, riboflavin, niacin, folate and vitamin C.

Meat, beans as well as eggs are n excellent source of protein as well as zinc, vitamin B as well as iron, while dairy products provide dietary protein and calcium.

No diet would be complete without a good balance of all 5 food groups, below is an example of the amount of each food group that is required to sustain an individual who has a daily caloric intake of 2000 calories:

Grains (whole grain cereals, pasta, bread, rice crackers) = 170.097 grams per day

Vegetables (can be fresh, frozen canned or even dried) = 2.5 Cups per day

Fruits (fresh, frozen, canned or dried, fruit juice in moderation, high sugar content) = 2 Cups per day

Dairy (Milk, cheese and yogurt) = 3 Cups per day

Meat and Beans (meat, poultry or fish and beans, seeds, nuts and peas) = 155.922g per day

Oils (fats from plans and animals e.g. Mayonnaise, salad dressing, sunflower or olive oil and margarine) = 6 tablespoons per day

This is just a guide line as different individuals require different caloric intake, according to their training and activities.

Next week we cover Macro – nutrients.

Reference : Essentials of Strength Training and Conditioning, 3rd Edition, T.R. Beachle & R.W. Earle (2008)

Picture courtesy of www.disabled-world.com

Wade Botha

Sport Scientist HONS Exercise Science 2010 UKZN

2012

Here's to a great year going forward, OWN IT!

Watch this space for a new series of posts on nutrition for health and performance shortly.

Wade