Chapter 7 Part 3

Nutritional Status  Inadequate nutrition ◦ Lethargy ◦ Early fatigue ◦ Irritability ◦ Poor training and competitive performance ◦ Increased incidence of injury ◦ Infection ◦ Excessive weight fluctuations

 A low-carbohydrate diet rapidly compromises energy reserves for vigorous physical activity or regular training.

 Training diet for physically active ◦ Adequate refueling day to day ◦ Recover between daily sessions  Multiple workouts ◦ Nutritional strategies  > 90 min – CHO becomes limiting factor

 Optimum diet for most sports ◦ CHO contributes 60-70% of total energy intake  After each bout of exercise ◦ Sufficient CHO to replenish glycogen stores  Maximize subsequent performance

 CHO – after exhaustive exercise ◦ 50 g every 2 h ◦ Moderate and high glycemic foods ◦ Goal – 600 g in 24 h

 Recommendations  6-10 g CHO/kg BM/day  Endurance training  10 g CHO/kg BM/day  This is quite a bit of food  70kg person = 2800 kcal of CHO

 Tour de France ◦ 6 h per day ◦ g/kg body weight/day ◦ Close to 4000 kcal of CHO/day

 More recently ◦ g/kg BM/hr ◦ Feedings every min ◦ Still over 3000 kcal of CHO/d

 Highest rates of glycogen storage ◦ First hour post exercise ◦ Activation of glycogen synthase  Glycogen depletion ◦ Exercise-induced insulin sensitivity  Permeability of muscle cell to glucose ◦ Storage rates  7.7 mmol/kg/wet weight/h (first 2 h)  4.3 mmol/kg/ww/h

 Exercise enhances energy metabolism  Exercise increases total energy expenditure ◦ Is there an increased need, deficiencies of vitamins? ◦ Do athletes have normal vitamin status? ◦ Do athletes require vitamin supplements?

 B complex ◦ Coenzymes in reactions during catabolism  Fat, CHO, protein ◦ Vitamin B 6 or Thiamin  Vitamin C ◦ Negligible effects on endurance  Vitamin E ◦ Deficiencies impair muscular function ◦ No benefit with excess consumption

 50 years of research  Fail to support vitamin supplements to improve performance  aerobic and anaerobic exercise

 Daily supplements of vitamin C  mg of per day  May reduce infections  Glutamine  Fuel for the immune system  Supplementation reduces the risk of infection

 Most often occur in: Vegetarians Groups with low energy intake Elimination of one or more food groups Individuals who consume  Processed foods  Simple sugars - low micronutrient density

 Contain doses at least 10 and up to 1000 times the RDA  Excess vitamin C = kidney stones  Excess vitamin B 6 = liver disease and nerve damage  Excess riboflavin (B 2 ) = impaired vision  Excess niacin = vasodilatation and inhibition of fatty acid mobilization during exercise

 Folate = trigger an allergic response  Excess vitamin E = headache, fatigue, blurred vision, gastrointestinal disturbances, muscular weakness, and low blood sugar  Excess vitamin A = toxic to the nervous system  Excess vitamin D = damages kidneys

 Aerobic exercise metabolism increases the production of free radicals.  Antioxidants: ß-Carotene Vitamin C Vitamin E Selenium, copper, manganese, and zinc Coenzyme Q 10

 Vitamin E deficient animals ◦ Reached exhaustion earlier  Sufficient Vitamin E ◦ Reduced oxidative damage to muscle fibers

 Innate ◦ Skin and mucous membranes ◦ Body temperature ◦ Specialized defenses  Natural killer cells, diverse phagocytes, and inflammatory barriers

 Continuous barrier ◦ Protection ◦ Dead cells on outside

 Acquired immune system  Specialized B (bone)- and T (Thymus)-lymphocyte cells.  B cells  Produce antibodies  T cells  Cytokines and toxic granules

 Moderate exercise A bout of moderate exercise boosts natural immune functions and host defenses for up to several hours.

 Exhaustive exercise A prolonged period of exhaustive exercise (and other forms of extreme stress or increased training) severely impairs the body’s first line of defense against infection.

 Excessive sweating  Loss of body water and related minerals.  Mineral loss  Replaced with well-balanced meals.  Single-mineral supplementation  Potential adverse consequences.

 Strenuous exercise may increase excretion of the following four trace elements: Chromium Copper Manganese Zinc

 Energy intake needs to be balanced with energy expenditure.  Regular moderate-to-intense physical activity  Increase daily energy intake to match their higher level of energy expenditure.

 Many athletes, particularly females, do not meet energy intake recommendations.  Active women (20-60 miles/wk)  35 kcals/kg BM  Discrepancies in reported kcals and activity?  Active become more sedentary when not exercising  Increased metabolic efficiency  Expend less energy