Chapter 8

Fig 23.1

 “Competition eating” ◦ Eating strategies  Before, during and after competition ◦ “preparation”  Weeks, months prior

 Factors to consider ◦ Duration and intensity of exercise involved ◦ Environmental conditions  Temperature, humidity ◦ Training status ◦ *Previously successful strategies*

 Factors associated with fatigue ◦ Deletion of glycogen stores ◦ Hypoglycemia (low blood sugar) ◦ Dehydration ◦ Hyponatremia (low total body sodium) ◦ GI discomfort

 CHO: To “top off” liver and muscle glycogen  CHO: digested and absorbed faster  Protein – thermogenesis raises body heat  Protein – breakdown requires water  Fat: Slows digestion ◦ Thus, the ideal pre-event meal should be high in carbohydrates and low in fats and proteins

Classical method  Prolonged strenuous exercise to deplete glycogen stores  A low CHO diet for three days while continuing to train  90% CHO diet for three days with light or no activity

Modified plan  Tapering workouts over several days from 90 to 40 minutes while eating 50% CHO diet  Two days of 20 minute workouts while eating 70% CHO diet  Day of rest eating 70% CHO diet before event

Fig 23.2

 CHO loading ◦ Hawley et al  > 90 min duration  Extend duration ~ 20%  Improve performance 2-3%  min duration  Little benefit

 Non-endurance events ◦ Glycogen stores normalize by 24 h rest ◦ Adequate CHO intake (7-10 g/kg BM/day) ◦ For events min  CHO loading doesn’t improve performance

 Readily digestible foods  Should contribute to energy and fluid requirements  Meals high in carbohydrates and relatively low in lipids and proteins  Three to four hours to digest and absorb the pre-competition meal

 Contains 150 to 300 grams of carbohydrates  Is consumed 2 to 4 hours before the event  Contains little fat  Contains little fiber

 High carbohydrate content  Supply fluids  Digest rapidly  Can be used for day-long events  Typically well tolerated in body weight supported activities (e.g. cycling)

 CHO should be eaten >1 hr prior to activity or just prior  Eating CHO in the last hour before competition  Insulin response  Rebound hypoglycemia  Fructose absorbs more slowly than glucose or sucrose. Can produce significant GI distress Avoid it

 Preventing hypoglycemia ◦ Pre-event CHO ◦ Consume 60g/hr during the event  1 liter of fluid  250 ml of 5-8% sugar solution every 15 min for a 70kg man