1. Nutrition for Sports Performance Lecture 4: James Brighton

2. Glycaemic Index  Is a ranking of foods from 0-100 based on the rate at which a food raises the blood sugar level. Foods with a low GI factor cause a slow rise in blood glucose level, whereas foods with a high GI factor cause a rapid rise.  Helps us to determine whether CHO is complex or simple.  All figures refer to the food when eaten alone – the GI factor can alter when other foods are consumed at the same time.

3. Glycaemic Index Low High Cereals Fruit Dairy Products Vegetables Biscuits and confectionery

4. Why are Fats Important?  They provide us with energy (although much more slowly than CHO).  Main source of energy when resting.  Keep skin in good condition  Help to keep our bodies warm.  Protect our vital organs  Carries fat soluble vitamins; A, D, E & K and helps with the absorption of these.

5.  Extra fat is stored under the skin as adipose tissue (triglycerides). This is not advantageous for sportspeople!!!  During exercise triglycerides are broken down into glycerol and free fatty acids (Oxygen is needed for aerobic metabolism).  These are then converted into glucose in the liver. At this point they can be used again by the skeletal muscles.

6. What are the 2 types of fats?  Saturated Fats: - More readily found in animal products such as milk, cheese, meats, cream and butter.  Generally found in solid form at room temperature.  Cholesterol content in these foods is quite high and this can cause an unhealthy amount to be present in body. Unsaturated Fats: - Found in Fish and plant products such as corn, nuts and soya beans.  Generally found in liquid form at room temperature.

7. Cholesterol:  Cholesterol occurs naturally in the body (liver) and has an important function in the regulation of cell membranes and hormones.  Additional and sometimes unnecessary levels of cholesterol come from the saturated or animal fats which we consume.  By replacing saturated fats with CHO or unsaturated fatty acids can help to reduce cholesterol.  Lack of exercise can also contribute to levels of CHL.  Can become a cause of heart disease due to the build up of cholesterol in the arterial walls.

8. Good Vs Bad Cholesterol  ‘BAD’ cholesterol (known as low density lipoprotein: LDL) ‘GOOD’ cholesterol (known as high density lipoprotein: HDL)  ‘BAD’ LDL-cholesterol can block up our arteries, whereas ‘GOOD’ HDL-cholesterol carries excess cholesterol away from our arteries and back to the liver, where it is broken down and recycled.  So, in terms of the potential damaging effects of cholesterol, what is important is the proportion of these two types of cholesterol in our blood.

9.  In pairs, discuss how excess fat may affect sporting performance?

10. Can Excess Fat Affect Performance?  Can adversely affect strength, speed & endurance.  Surplus fat is surplus baggage.  Can be costly in terms of energy expenditure.

11. Examples in Sport  Endurance sports – Surplus fat can reduce speed and increase fatigue.  Explosive sports - Non-functional weight. Slows you down & decreases mechanical efficiency. Muscle is useful weight, fat is not.  Weight matched sports – Boxing, judo. Greatest % of muscle and smallest % of fat has advantage.

12.  Can fat be an advantage in some sports?

13. Is Fat an Advantage in Certain Sports?  A heavy body can generate more momentum to throw object or knock over opponents.  This weight shouldn’t be fat though! Muscle mass is more advantageous.  Muscle is stronger and more powerful.

14. The Exception…….. Sumo!!!!!