You at your best Loughborough Sports Day 2012 Dr Ian Gallen (Consultant Physician & Endocrinologist) AN A Polite Notice The information presented here represents the view and opinions of the speaker & not necessarily those of Animas & LifeScan United Kingdom & Ireland. You at your best Loughborough Sports Day 2011 AN A Basic Physiology How does the body work during exercise? Basis of fitness Managing diabetes to promote performance and reduce variation on blood sugar AN A Exercise Terminology Duration of activity 020 minutesShort duration 20 minutes to 1 hourMedium duration Greater than 1 hourLong duration (or endurance) Intensity of activity Low intensityUp to 40% maximum heart rate in general activities from which an individual will not feel tired or out of breath, e.g. resting, activities of daily living Moderate intensity4080% maximum heart rate in general activities from which an individual will feel warm and moderately out of breath, e.g., jogging, cycling, and fast walking High intensity80100% maximum heart rate in general activities which an individual will not be able to maintain for longer than a few minutes, e.g. sprinting Intermittent high intensityTypically characterises many popular sports with periods of low or moderate exercise intensity interspersed with bursts of high-intensity activity, e.g. football, hockey, rugby, netball, etc. Likely also to reflect some fitness classes and gym work Key definitionsVO 2max = the maximum rate at which an individual can utilise oxygen = cardiac output (heart rate x stroke volume) x O 2 a-v (the arterial venous difference). Estimate for maximum heart rate = 220age(years) Perry E, Gallen IW. Pract Diab Int. 2009;26:116123. AN A Muscles You at your best Loughborough Sports Day 2011 AN A What are muscles? Muscles are the contractile tissue of the body, and produce all movement, and circulation in the body. are made of groups of cell, which contain the contractile proteins actin and myosin. contain structures to generate energy, the mitochondria and some fuel stores. are rich in arteries and veins to carry fuel and oxygen to the muscles and veins to carry waste products and carbon dioxide away. are the meat which we eat, and the red colour is due to another iron rich protein (myoglobin) which can store oxygen. contain a temporary store of energy in the form of creatine, and some fat and a starch (glycogen). AN A Structure of muscles AN A How do muscles contract? When you want to move, electrical impulses come from the brain, down through the spinal cord and are transmitted through the motor nerves to the muscles. At the junction between the nerve end and the muscle, chemical signals are released from the nerve endings. Calcium to enter the muscle cell, and this enable the troponin proteins to move the myosin up the actin molecule. This causes the whole structure to shorten, and this contraction is the fundamental basis of all muscle contraction. To release the bond between actin and myosin needs energy, to shorten the muscle further or to relax the muscle. When the signal for contraction ends, the calcium is pumped back into the sarcoplasmic reticulum, and the muscle relaxes. AN A Contractile proteins of muscles AN A Microscopic structure of muscle AN A Comes from the high energy phosphorous containing compounds, adenosine triphosphate (ATP). ADP is returned to ATP, from another high energy phosphorous source creatine phosphate, and from the energy factory of the muscle, the mitochondrion. Another source is from enzymes which burn glucose in other parts of the muscle cells. In conditions of reduced oxygen availability, this is the source of energy in anaerobic exercise. A diet rich in creatine has the potential to increase the availability of creatine phosphate, which can increase high energy phosphate supply during intense exercise. Mitochondria can burn glucose, fats and ketones to make carbon dioxide and water. They will do so given an adequate supply of oxygen. How does the muscle get and use power? AN A Mitochondrion, the power house of muscle AN A Energy for exercise You at your best Loughborough Sports Day 2011 AN A Glucose comes from Glycogen stores in muscle Liver glycogen via the cirulation Glycerol Lactate Amino-acids Free fatty acids from fat stores Ketone bodies from the liver The ratio between CO 2 released (VCO 2 ) and oxygen consumed(VO 2 ). RER = VCO 2 /VO 2. RER for CHO is 1.0; RER for Fat is.70 The RER value at rest is usually 0.78 to Energy for exercise AN A GH/Cortisol EPI: epinephrine; FFA: free fatty acid; GH: growth hormone; NE: norepinephrine Glucagon Glucose Ketones EPI/NE Ian Gallen AN A Upper limit of a persons ability to increase oxygen uptake. Good indicator of cardiorespiratory endurance and aerobic fitness. Can differ according to sex, body size, age, and, to some degree, level of training. Expressed relative to body weight in ml of O 2 consumed per kg body weight per min (ml kg -1 min -1 ). College aged females and males approx. 38, 44, respectively Elite athletes are > 70 Maximal Oxygen Uptake (VO 2max ) AN A Exercise Types You at your best Loughborough Sports Day 2011 AN A Anaerobic (lactate inhibited) Sprint running, speed climbing, sprint swimming. Mixed prolonged Football, Rugby, Squash, Dancing. Prolonged aerobic Long distance running, cycling. Intense aerobic, limited by later anaerobic lactate build-up Middle distance running, rowing, canoeing, cycling with hills/sprint finishes Exercise Types AN A During the first few seconds of exercise, muscles use internal stores of high energy phosphate compounds (creatine phosphate) as the power source, Then switches to burning glucose from muscle glycogen by the mitochondria. If oxygen is plentiful, this continues, but the fuel comes from other parts of the body, and can be glucose, fats or ketones to make energy. Typically, endurance sports are aerobic. Training measures which improve the supply of oxgen to muscles, and the function of mitochondria will improve the aerobic capacity, and thus the endurance of exercise. Prolonged aerobic exercise at low intensity is the best for weight control. Any antigravity exercise such as running or using a treadmill with an incline in a gym for 40 minutes at a time will help burn fat. Aerobic Exercise AN A Heart rate and Training You at your best Loughborough Sports Day 2011 AN A Calculate your maximum heart rate your age from 220 (e.g. for a 22 year old person it is 198 beats per minute). During your exercise, measure your heart rate over a minute at the wrist