1. Nutrition for Sports Performance Lecture 4: Mike Tambling

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.  Low Glycaemic Index foods (55 or less)  Medium Glycaemic Index foods (56 to 69)  High Glycaemic Index foods (70 or more)

3. LOW GI FOODS Roasted and salted peanuts14 Low-fat yoghurt with sweetener14 Cherries22 Grapefruit25 Pearl barley25 Red lentils26 Whole milk27 Dried apricots31 Butter beans31 Fettucine pasta32 Skimmed milk32 Low-fat fruit yoghurt33 Wholemeal spaghetti37 Apples38 Pears38 Tomato soup, canned38 Apple juice, unsweetened40 Noodles40 White spaghetti41 All Bran42 Chick peas, canned42 Peaches42 Porridge made with water42 Lentil soup44 Oranges44 Macaroni45 Green grapes46 Orange juice46 Peas48 Baked beans in tomato sauce48 Carrots, boiled49 Milk chocolate49 Kiwi fruit52 Stoneground wholemeal bread53 Crisps54 Special K54 Banana55 Raw oatbran55 Sweetcorn55

4. MEDIUM GI FOODS Muesli, non toasted56 Boiled potatoes56 Sultanas56 Pitta bread57 Basmati Rice58 Honey58 Digestive biscuit59 Cheese and tomato pizza60 Ice cream61 New potatoes62 Coca cola63 Wholemeal bread69 Apricots, canned in syrup64 Raisins64 Shortbread biscuit64 Couscous65 Rye bread65 Pineapple, fresh66 Cantaloupe melon67 Croissant67 Shredded wheat67 Mars bar68 Ryvita69 Crumpet, toasted69 Weetabix69

5. HIGH GI FOODS Mashed potato70 White bread70 Watermelon72 Swede72 Bagel72 Branflakes74 Cheerios74 French fries75 Coco Pops77 Jelly beans80 Rice cakes82 Rice Krispies82 Cornflakes84 Jacket potato85 Puffed wheat89 Baguette95 Parsnips, boiled97 White rice, steamed98

6. 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.

7. 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.

8. 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.

9. 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.

10. 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.

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

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

13. 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.

14. Can fat be an advantage in some sports? Discuss …….. What if you want to put on weight for your sport, would fat be better than nothing??

15. 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.

16. The Exception…….. Sumo!!!!!