Exercise and Sport Physiology. Aims: To define the terms ‘energy’, ‘work’ and ‘power’. Identify examples of potential, chemical and kinetic energy

Energy, Work and Power. ENERGY: The ability to perform work. Usually measured in joules (j). WORK = FORCE x DISTANCE. (See pg 270 for E.G.) POWER = WORK/TIME. Power is considered to be a combination of strength and speed and is measured in watts (W) ENERGY AND WORK MEAN THE SAME THING. THEY ARE INTERCHANGEABLE AS CONCEPTS. ENERGY BEING THE CAPACITY OF A SYSTEM TO DO WORK.

Energy. Energy can exist as three different form! What are they? THE ENERGY INVOLVED IN THE PRODUCTION OF WORK IS KINETIC ENERGY. (RUNNING ETC) ENERGY WHICH IS STORED, IS POTENTIAL ENERGY CHEMICAL ENERGY STORED IN OUR BODIES. E.G. ATP, CARBOHYDRATES AND FATS.

ENERGY OUTPUT IF WE WERE ABLE TO CALCULATE THE FULL ENERGY VALUE OF ALL FOOD EATEN BY A PERSON AND COMPARE THIS WITH MEASURED ENERGY OUTPUT, WE WOULD FIND THAT ONLY A SMALL PROPORTION OF THIS ENERGY IS CONVERTED INTO USEFUL WORK. TO MEASURE THIS YOU USE THE; DIRECT METHOD.THIS INVOLVES THE MEASURING THE ENERGY USED DURING EXERCISE BY MEASURING THE BODY’S HEAT PRODUCTION IN A CALORIMETER CHAMBER. THE HEAT ENERGY THAT IS CREATED BY THE HUMAN RADIATES THE WALLS AND WARMS THE WATER.

How energy is used in chemical reactions. ENDOTHERMIC. A CHEMICAL REACTION THAT REQUIRES ENERGY TO BE ADDED FOR IT TO PROGRESS FURTHER. EXOTHERMIC. THESE ARE CHEMICAL REACTIONS THAT RELEASE ENERGY AS IT PROGRESSES. (THE BREAKDOWN OF ATP WOULD BE EXOTHERMIC) ATP — ADP + P + ENERGY

ATP WHAT IS IT? ATP IS STORED WITHIN THE MUSCLES. ATP IS ADENOSINE TRIPHOSPHATE. THIS COMPOUND IS THE ONLY IMMEDIATELY USABLE FORM OF ENERGY STORED IN OUR BODIES. ATP IS STORED WITHIN THE MUSCLES. WHAT’S THE PROBLEM WITH THIS? WE CAN ONLY STORE A VERY SMALL AMOUNT OF ATP AT ANY ONE TIME.

Cont. THE TOTAL MASS OF ATP IN THE WHOLE BODY IS ONLY 85g- ENOUGH TO LAST FOR ABOUT 2-3 SECONDS OF EXERCISE! TO MAINTAIN EXERCISE AFTER 2 SECS, ATP HAS TO RE-SYNTHESISED!

Exam questions. Define the term ‘energy’ and explain the role of ATP within the body. [3]. Define the term ‘power’, giving units of measurement and describe a test used to measure power. [4]. (Standing broad jump etc!!).