<meta content="text/html; charset=utf-8" http-equiv="Content-Type" /><meta content="Word.Document" name="ProgId" /><meta content="Microsoft Word 11" name="Generator" /><meta content="Microsoft Word 11" name="Originator" />
classid="clsid:38481807-CA0E-42D2-BF39-B33AF135CC4D" id=ieooui></object> <style> st1\:*{behavior:url(#ieooui) } </style> <![endif]--><style> </style>

1. BASIC EXERCISE PHYSIOLOGY

Physical Activity: Any skeletal muscle contraction (concentric and eccentric) that results in increased energy expenditure. Includes all exercise and sport (Isometric muscular contractions do not result in movement because length does not change but require energy expenditure).

Exercise & Sport: Exercise is repetitive physical activity or movements to improve and/or maintain fitness or health. Sport is physical activity or movements involving rules and competition.

Acute effects of physical activity: means (for e.g.) what happens to heart at the end of 10 minutes of cardio or what happens in muscle at end of a workout.

Chronic (adaptive) or long term effects: means (for e.g.) how RHR will be affected at the end of 12 weeks of strength and cardio training program.

Ergometry: Methods used to control or measure work rate or intensity. Experiments done on machines, ergometers in laboratory based experiments. Ergometer measures work rate, enables physiologist to measure energy expenditure.

SI Units (System International Units): Standardized unit of measurement by exercise physiologist.

Force: is measured in Kilopound (kp). 1kp = force exerted by 1kg mass in normal gravity. SI unit of force is Newton (N). 1kp = 1kg = 9.80665 N.

Work: work = force x distance. Force is measured in Newton (N). Mass is measured in kg.

For example: movement of a 2kg mass over 1 meter distanceâ?¦..

From the above conversion table, to convert mass into force = x 9.81

2kg x 9.81N = 19.62 N (force). Work = 19.62 N (force) x 1m (distance).

Work = 19.62 Nm (Newton-Meter)

1Nm = 1joule. Therefore 19.62 Nm = 19.62 J. Since 1kg = 1kp, 2kg = 2kp.

Therefore 2kp x 1m = 2kpm = 19.62 J. It means, moving 2kg over 1 meter will require following work to be performed.

Work = 2kp x 1m

= 2kpm (kilopound meters)

Power: also called as work rate. Function of time: Power = work ÷ time.

For example: performance of 150kpm (or kgm) of work in 1 minute will produce work output of: Power = 150 ÷ 1 = 150kpm min^-1

^ 

SI unit for power is Watts (W). Power output if 150kpm min^-1 ÷ 6.12 = 24.51 W^-1

^ 

Measurement of energy expenditure: Ability to perform physical activity depends upon ability of muscle to convert chemical energy into mechanical energy. This conversion depends upon:

1. Ability of circulatory system to deliver O₂ to muscle tissue.
   
2. Ability of tissue to extract and use O_2 
   

Athlete may work at 100% or 50% or some % of maximum capacity of circulatory system or O₂ utilization. This work rate or % of max capacity is called Exercise Intensity.

ACSM classifies exercise intensity as either %of Max O₂ uptake or Max Heart Rate or in Metabolic Equivalents (METs).

Max O₂ uptake = max amount of O₂ body can utilize during exercise at sea level.

Work at 100% O₂ = Supramaximal (e.g. sprints or 1RM)

1MET = 3.5 ml kg^-1 min^-1 O₂

Other intensity measurements:

Moderate exercise = below lactate threshold. (The intensity at which adequate oxygen is unavailable is referred to as the lactate threshold or anaerobic threshold.)

Heavy exercise = above lactate threshold.

Strength intensity as % of 1RM (limit strength).

Intensity Measurements:

Muscular strength assessment: 1RM â?? this is generally for advanced lifters/athletes only. For upper body â?? barbell bench press. For lower body â?? 45⁰ leg press.

Wilkâ??s formula â?? 3 power lifts â?? add total â?? apply formula to obtain Wilkâ??s index.

Muscular endurance: Push-ups (for women modified push-up) max reps. Sit-ups â?? in 1 minute max.

Cardiovascular endurance: THR test. Dr. Karvonenâ??s HRR, Cooperâ??s 12 minute run/walk/swim/cycle test â?? age wise, Harvard Step test (Heart rate recovery test) age wise, Borgâ??s perceived exertion rate â?? rating 6 to 20. (Rating 15-16 = THR 70% MHR), Rockport walking test.

Energy expenditure: Measurement of energy expenditure enables to calculate Metabolic cost of exercise. Energy expensed by body is expressed as heat production. Heat production is measured in calories. (Calories = amount of heat to raise temperature of 1kg of H ₂O by 1⁰C. 1 kilocalorie (kc) = 1,000 calories.

Oxygen cost: Oxygen cost of performing work (VO₂) depends primarily on work rate. Oxygen cost reflects metabolic cost of exercise. Oxygen cost is measured through indirect calorimetry. Expired air is collected in Douglas bags which is then assessed for

CO_2, O_2, total quantity, temperature., etc.

O₂ uptake is calculated against atmospheric(A) temperature(T) and pressure(P) in the laboratory and water vapor saturation(S) in the captured air. These ATPS volume is corrected to a standard (S) temperature (T: 273 K or 0⁰ C), standard pressure (P: 760 mmHg) and volume that they would be in dry air (D). This gives STPD volume.

Absolute O₂ Cost â?? liters (Lmin^-1) or milliliters (ml min^-1) of O₂ consumed per minute. Used during activity which is not weight bearing â?? e.g. cycling.

Relative O₂ Cost â?? milliliters of O₂ consumed per kilogram of body mass per minute (ml kg^-1 min^-1). Used during activity which is weight bearing â?? e.g. running.

Total O₂ Cost of movement includes oxygen cost of rest, oxygen cost of moving legs on the cycle ergometer, or whole body on treadmill, plus oxygen cost of performing work.

True O₂ Cost is oxygen cost above that of rest and leg and body movement. On cycle, leg movement is measured against zero load/resistance (0W). Oxygen cost of performing additional work is then measured as difference between O₂ uptake at a given work rate and that recorded at 0W.

Caloric Cost of exercise provides estimation of metabolic energy utilized in producing skeletal work. Estimated from oxygen cost of work.1 liter of O₂ = 5 calories (20kJ).

Maximal Oxygen Uptake/Consumption (VO₂ max) is the maximum rate that the body can consume O₂ during physical activity at sea level. Can be increased through cardiovascular training Average man 30-55ml kg min^-1 Average woman 25-40ml kg

min^-1 Endurance athletes may have VO₂ max greater than 80ml kg min^-1