EDU2EXP Exercise & Performance Nutrition for Exercise

EDU2EXP Exercise & Performance What is Nutrition? Science involving study of food and liquid requirements of the body for optimal functioning

EDU2EXP Exercise & Performance Nutrients Macronutrients –Carbohydrates Monosaccardides- Glucose, Fructose, galactose Disaccharides- Sucrose, Lactose, Maltose Polysaccharides –Plant –Animal –Protein Complete Incomplete –Lipids Saturated Unsaturated Micronutrients –Vitamins Fat Soluble Water Soluble –Minerals Essential Trace Water

EDU2EXP Exercise & Performance Carbs Monosacchardides- –Glucose –Fructose –Galactose Disaccharides –Sucrose –Lactose –Maltose Polysaccharides –Glycogen- –Starch- –Fibre

EDU2EXP Exercise & Performance Carbs- The basics Glucose is a type of monosaccharide that is in the food that we consume Blood glucose is used to fuel the working muscles Called glycogen when stored in muscles or the liver

EDU2EXP Exercise & Performance What happened to your breakfast?? Carbohydrate meal is eaten and digested, Blood glucose levels rise, and the pancreas secretes insulin GLYCOGENESIS- glucose converted to glycogen [for ST storage] as long as both insulin and glucose remain plentiful Blood glucose used for immediate energy requirements When glucose levels begin to fall, insulin secretion is reduced, and glycogen synthesis stops. About four hours after a meal glycogen begins to be broken down to be converted again to glucose [GLYCOGENOLYSIS] For the next 8–12 hours, glucose derived from liver glycogen will be the primary source of blood glucose to be used by the rest of the body for fuel.

EDU2EXP Exercise & Performance Carbs terminology Glycogenesis = glucose  glycogen Glycogenolysis = glycogen  glucose Gluconeogenesis=non CHO sources  glucose Glycolysis = Glucose  Pyruvic acid  Krebs cycle 4 calories of Energy (+ Co2 and H20) 1 gram glucose (+ oxygen)

EDU2EXP Exercise & Performance Storage LIVER- Only the glycogen stored in the liver can be made accessible to other organs. 100–120 g stored in an adult MUSCLES- lower concentration (1% of the muscle mass), but the total amount exceeds that in liver. Small amounts of glycogen are found in the kidneys, and even smaller amounts in certain glial cells in the brain and white blood cells Once muscle glycogen stores are depleted  performance decreases

EDU2EXP Exercise & Performance

Glycaemic Index Index for comparing the blood glucose response from the ingestion of different foods. - The more complex the carbohydrate, and the more fat, protein and fibre in the food  lower glycaemic index. High = GI>70 Mod = GI Low = GI<55 Lower = slower

EDU2EXP Exercise & Performance Whole wheat pasta Glucose White breadIngestion Note the differences in the area under the curve Note that the blood glucose response to white bread is the standard reference

EDU2EXP Exercise & Performance Proteins ‘Building blocks’ Complete- Animal – Incomplete- plant

EDU2EXP Exercise & Performance Lipids Saturated Unsaturated –Monounsaturated –Polyunsaturated

EDU2EXP Exercise & Performance

Micronutrients Vitamins –Vital to release energy from food Minerals –Important in catabolism and anabolism of macronutrients Athletes –Iron, especially for women athletes –Calcium.

EDU2EXP Exercise & Performance Energy for Sport

EDU2EXP Exercise & Performance Major Considerations RDI’s - CHO & protein requirements Pre competition meals Fluid replacement

EDU2EXP Exercise & Performance Daily intake Normal people 1500—2500 calories Athletes 1400 (gymnasts) – 6000 (TDF cyclists) Carbohydrate= 55-60% Fats <35% Protein= 10-15%

EDU2EXP Exercise & Performance RDI’s- Protein Sedentary people and recreational athletes have similar protein requirements –Sedentary Adults: 0.8 to 1 gram of protein p/kg BM. –Athletes: g protein p/kg BM 87 kg x 1.8 g or 87 kg x 1.2g = g p/day x 26 x 232 x 2

EDU2EXP Exercise & Performance RDI’s- Carbs Depends on sport –Normal people: 5 g/kg –Athletes: 5-13 g /kg depending on training intensity 59 kg x 8 g = 472 g p/day

EDU2EXP Exercise & Performance Preparation for Competition- Carb loading In general –Taper exercise, 50% CHO diet 1 st 3 days –V. low exercise, 80% CHO diet 3 days prior Strict protocol –Depletion Day 1- Exhaustive exercise Day 2,3,4  mod intensity training & low carb intake (100g p/day) Day 5,6,7  High CHO intake ( g)

EDU2EXP Exercise & Performance Bergstrom, Hermansen, Hultman, & Saltin (1967) Mixed dietLow Carb dietHigh carb diet

EDU2EXP Exercise & Performance Day of Competition Nutrition 1-4 hours before= Large CHO meal – calories –150 – 300g carbohydrate (3-5g CHO p/kg BW) OR 4 hours before – meal (200 g CHO) 1 hour before- snack (100g CHO)

EDU2EXP Exercise & Performance Rebound hypoglycaemia High GI carbohydrate consumed min before exercise  it can stimulates insulin secretion  converts glucose to glycogen and stores it  low blood glucose levels Less fuel available for exercise Pg 333 of text

EDU2EXP Exercise & Performance Liquid Carbohydrate Ingestion  Suited for long duration (> 60 min) exercise where a glucose source is needed to support blood glucose  As long as it is consumed late in exercise when muscle glycogen stores are low it will not cause rebound hypoglycaemia  Need at least 45 g/CHO/Hr  During hot and humid conditions, a lower [CHO] drink would allow greater volumes to be ingested.  CHO should be mostly glucose

EDU2EXP Exercise & Performance CHO ingestion every 20 min CHO ingestion late in exercise No CHO ingestion 65-75% VO2max

EDU2EXP Exercise & Performance Post Competition Depends on time and intensity –after low intensity exercise mmol/kg/Hr –after high intensity exercise - ~ 15 mmol/kg/Hr Important to consume 2 hours post exercise while rate of glycogen synthesis is high Large carbohydrate rich meal With some addition protein Rest Rehydrate

EDU2EXP Exercise & Performance Liquids - Rehydration Sweat rates increase with intensity of exercise Fit people sweat more and sooner; and it is more dilute Can be up to L/hr –Sodium (Na), Potassium (K), Magnesium (Mg), Chlorine (Cl) Loss of body weight > 3% = danger Consume ml per hour

EDU2EXP Exercise & Performance Fluids- 2 hours before: – ml fluid During – ml every minutes –If > 1 hour- 4-8% CHO plus Na and Cl After –Continue H2o consumption- thirst not an accurate indicator – ml for every kg lost –Caffeine, energy drinks and alcohol further dehydrate Recommendations from text box in page 347

EDU2EXP Exercise & Performance Gastric emptying Maximal rates of L /hr with gastric volumes of mL.

EDU2EXP Exercise & Performance Nutrient and electrolyte content of commercial drinks.

EDU2EXP Exercise & Performance Important nutrients & fads Female Athlete Triad Steroid use/abuse Over-consumption proteins Muscle building powders Creatine

EDU2EXP Exercise & Performance Summary Sports nutrition has a huge impact on performance Nutrition and rehydration account for huge gains Need to be careful of rebound hypoglycaemia and gastric emptying Expensive pills, potions and fads account for minute gains if any at all