NUTR 202 1nd Edition Lecture 19 Ch 10 Nutrition Fitness and Physical Activity cont Developing a Fitness Program should include all components of exercise Cardiorespiratory Aerobic exercise do most days of the week Muscle strength and endurance 2 3 days per week at beginning of exercise program Not on consecutive days Flexibility 2 7 days per week Body composition Change in progressive manner to provide overload principle frequency intensity time and type Per 2010 Dietary Guidelines for Americans for reduced risk of chronic disease moderate exercise recommended for 30 min day most days of the week 150 minutes week of moderate intensity Or 75 minutes week of vigorous intensity For additional health benefit and healthy weight Increase duration or intensity of exercise ACSM Exercise Recommendations Moderate Intensity Minimum of 150 min per week 150 200 min per week lose weight prevent weight gain The recommendation is 10 000 steps day to prevent chronic diseases maintain healthy weight Aerobic activity duration of activity which days Move more choose activities you enjoy walk more take stairs and find friends to do activities with Set specific goals stay motivated vary exercise and keep your exercise safe Ingredients for Fitness Regular PA right foods fluids Body will use glucose for E regardless of intake macronutrient Glucose is stored as glycogen in liver and in muscles If low blood sugar release glucagon stimulate the liver to break down glycogen to glucose bloodstream Metabolism chemical process that converts nutrients to energy ATP Occurs in muscle Either have glycogen or FAs main source of nutrients and you need oxygen to get energy Myoglobin stores oxygen in muscle Anaerobic without oxygen only uses glucose and generates lactic acid Aerobic with oxygen uses glucose protein fat more efficient produces more ATP per glucose and occurs in mitochondria Glucose is used solely in anaerobic metabolism In muscle 525 g stored in liver 100g and 25 g in blood Therefore 650g CHO X 4 2600 calories that can be used In your muscle you have 1 050 calories 2 hours of exercise Glycogen in liver is to regulate blood glucose levels especially for brain Remember this store is limited FAs stored in adipose tissue unlimited Which nutrient can be used to produce energy in the absence of oxygen GLUCOSE anaerobic Source of fuel used during exercise depends on duration of exercise and intensity of exercise Immediate source of energy for body functions Adenosine Triphosphate or ATP What type of energy metabolism is used during the first few minutes of exercise Anaerobic can only use glucose for fuel Energy metabolism in the muscles Adenosine triphosphate ATP that was stored Creatine phosphate CP ATP and CP used up in 15 seconds After these stores are used up Glucose converted to ATP Long term exercise After 2 minutes of exercise oxygen delivery to muscles increased shift to predominantly aerobic metabolism more efficient at producing energy more ATP Fuel source Glucose FAs and some proteins especially in endurance exercise either converted to glucose or E source Heart Rate Respiration Rate increases so that after 2 3 min enough O2 delivered to muscles to support aerobic metabolism which uses FAs Glucose to make ATP With low intensity exercise Predominately aerobic metabolism Glucose and FAs utilized The higher intensity the exercise Relies more on anaerobic metabolism more glucose used glycogen stores can be depleted and may lead to fatigue After 1 min of jogging anaerobic metabolism using ONLY GLUCOSE Regular exercise and training leads to changes in body s physiological response to exercise Aerobic exercise improves aerobic capacity by improving oxygen delivery to muscles ability for muscles to use oxygen to generate ATP enhanced utilization of fatty acids for energy this spares glycogen leading to increased glycogen storage Diet needs for PA energy to fuel activity protein to maintain muscle mass micronutrients to permit use of energy yielding nutrients coenzymes and water to transport nutrients and cool the body Remember energy expenditure 50 65 BMR 25 50 PA and 5 10 thermic effect of food Energy expended during activity depends on Intensity duration and frequency of PA Weight of exerciser monitor weight The more intense the activity the more energy it requires The more time spend exercising the more energy required Female Athlete Triad unhealthy weight loss practices impair performance adversely affect heart kidney temperature regulation and electrolyte balance Know the three components of the triad 1 Eating disorder food restriction risk of deficiency of Ca low bone mass Low estrogen Should people who exercise regularly have majority of calories come from protein No Should come from CARBOHYDRATE Calories of an athlete are always increased fats will remain same May increase to 70 to maximize glycogen stores Protein Endurance athletes 1 2 to 1 4 g protein kg of body weight Strength athletes 1 2 to 1 7 g kg day Athletes should consume adequate amounts of the following vitamins and minerals B vitamins coenzymes need quick metab Calcium Aerobic metabolism increases free radical production Vitamin C and E betacarotene selenium Or may be at risk for cancer Eat nutrient dense food Minerals Maintenance and growth of healthy bones muscle contraction Calcium Catalyst for enzymes Magnesium Muscle contraction and nerve transmissions Sodium Potassium Fluid Balance Sodium Transport nutrients and oxygen to and within cells Iron Increased iron is needed increased hemoglobin myoglobin iron containing proteins RBC Iron losses with prolonged training Feces urine sweat Female athletes menstruation Particular concern if trying to maintain low body weight Foot strike hemolysis results from high impact events such as running Low IRON levels low hemoglobin myoglobin reduced capacity to transport O2 to muscle early fatigue Iron deficiency anemia Female Athletes Endurance Athletes Make Weight Athletes prone to MIGHT need Fe supplement Sports Anemia During exercise blood volume increases lower concentrations of hemoglobin corrected on its own the body can be adapted to training produce more red blood cells Think increase in PLASMA Corrected w training Exercise recomm Need extra fluids if thirsty already dehydrated Schedule regular fluid breaks Adequate fluids BEFORE DURING and AFTER IF Exercise Up to 1 hr water alone 1 hr or longer Sodium Carbs e g sports drink to avoid dehydration AND Hyponatremia BUT Avoid high sugar