1. Energy Concepts for Exercise Physiology DEFINE ENERGY - the capacity to perform work (measured in calories or joules) DEFINE WORK - force x distance moved (measured in calories or joules) DEFINE POWER - work performed per unit of time (measured in watts)

WHERE DOES ENERGY COME FROM????? All energy on earth comes from the sun Plants and animals use this light energy to form carbohydrates, fats and proteins Animals (including humans) eat the plants and other animals and their muscle fibres convert the CHEMICAL ENERGY from these sources into KINETIC (MECHANICAL) ENERGY in order to perform movement or for storage as POTENTIAL ENERGY

Types of energy Chemical Mechanical Heat Light Electric Nuclear

Where is energy stored? Energy is stored in food A complex series of reactions break down carbohydrates, fats and proteins to provide energy for muscle contraction How much energy is stored in a BIG MAC, BANANA, EGG and a CAN OF COKE? BIG MAC = BANANA = CAN OF COKE= GLASS OF MILK= 150 Kcal (calories) EGG= 70 Kcal (calories)

What happens next? The food we consume is broken down as a result of a series of chemical reactions – this creates energy This energy is then stored in the bonds of chemical substances (eg: ATP) POTENTIAL energy (that is stored in the chemical bonds) is then transferred into KINETIC energy when the bonds are broken. This energy is then used (in muscle contractions) and provides movement Energy is neither created nor destroyed; it is merely transformed from one form of energy to another

Measurement of energy 1. Why measure energy? To plan training and specific diet programmes Weight control programs To ensure intake is sufficient for output 2. Basal Metabolic Rate (BMR) BMR is the energy required for a person to function physiologically Values Average between calories 3. Total Metabolic Rate (TMR) TMR is the BMR plus energy requirements of an activity/lifestyle Values Average between calories However, an athlete training hard could need up to 7000 calories

Estimating your BMR The estimated BMR for a male is that 1kg of body weight burns 1 kcal per hour EXAMPLE: 70 kg MALE=70 kgx 1 kcal x 24 hrs =1680 kcal

Units of measurement Energy in sports science is measured in CALORIES A CALORIE is defined as the amount of heat energy that is required to raise the temperatre of 1g of water through 1 degree celcius CALORIES = 1 kilocalories (kcal) JOULES= 1 kilojoule (kJ) - 1 cal= joules Most food labels now give calorific values

WORK To measure physical activity we need to calculate the work done WORK = FORCE x DISTANCE WORK is measured in calories or joules FORCE is measured in NEWTONS FOR EXAMPLE: If you lift a 5kg weight through a vertical distance of 2m the work performed is calculated as follows: WORK = 5kg x 2m = 10kgm (covert to joules by multiplying by 9.81 = 98.1 joules)

POWER POWER is the work that is performed per unit of time and measured in WATTS POWER = WORK TIME The concept of POWER is important because it describes the rate at which WORK is being performed

Oxygen Utilisation All energy releasing transactions in the body ultimately depends on the utilisation of oxygen 5 kcal of heat energy is produced for every litre of oxygen consumed If we can measure a persons oxygen uptake during exercise then we can estimate their energy expenditure To do this you would need a gas analyser (Douglas bag) to measure oxygen consumption directly

HOMEWORK In preparation for next weeks lesson please define the following words: –Central nervous system (CNS) –Peripheral nervous system (PNS) –Sensory portion –Motor portion –Motor neurone –Cell body –Dendrites –Axon –Myelin Sheath –Nodes of Ranvier

Basic Chemistry for Sports Science All living and non-living things are composed of MATTER MATTER exists in solid, liquid and gaseous states MATTER is anything that occupies space and has a mass MATTER is composed of ELEMENTS and the periodic table gives a complete list of known ELEMENTS 26 ELEMENTS occur in the human body with carbon (C), oxygen (O) and nitrogen (N) making up about 96% of its mass

As a MATTER of fact…… Each ELEMENT is made up of ATOMS The smallest atoms (H) are less than cm in diameter If 50 million of the largest ATOMS were placed end to end, they would measure approx. 2.5cm!

ATOMS An ATOM consists of neutrons, protons and electrons The NEGATIVELY charged electrons (e-) orbit the nucleus which is made up of POSITIVELY charged protons (p+) and uncharged neutrons PHEW!

ATOMIC STRUCTURE The atomic structure of an atom is equal to the number of PROTONS it has: FOR EXAMPLE: Hydrogen = 1, Carbon = 6