Lab 1 Flashcards
What is work and what are the three types of work
Work is the transfer of energy
- chemical work = ATP biosynthesis
- cellular work = active transport
- mechanical work = accomplished with muscular contractions
what is the equation to find work? SI units?
Work (J) = force (N) x distance (m)
What is energy
capacity to do work –humans transform chemical energy from food to perform work (measured in Calories)
What is power
rate of work done (power = work/time), rate of transforming metabolic energy to physical performance
ie. aerobic or anerobic
power
SI unit is watt (W) or kcal/min, or kgm/min, or kpm/min
how do you convert kgm or kpm to SI unit joule
for every mass of 1 kg must be multiplied by acceleration due to gravity (9.81 m/s2)
What are absolute terms for physiological and performance data
actual measured values with units
- ie. 80kg, 10m, 300 W, 10 L*min-1 rate of VO2
What are relative terms for physiological and performance data
data expressed in relation to another value (usually in relation to body mass)
- ie. a 50 kg subject is exercising at an absolute rate of oxygen consumption of 1L/min
Absolute intensity can be expressed as what
percent peak power output
10 mph as % of peak running speed
Exercise intensity can be expressed in absolute, relative or both terms
both – =10 Lmin-1or 10 L/minkg
What is a graded exercise test
work rate changes during the test and is usually an independent variable
for graded exercise test on cycle ergometer, subject exercise for 3 stages at 50, 100, and 150 W for 4 minutes per stage
on treadmill, subject run at constant speed but increase grade by 1% every 2 minutes or run at fixed grade but speed change every 2 minutes
What is a constant work exercise test
work rate remains fixed throughout the test
time is usually independent variable
ie. interested in monitoring HR response in subject over 30 minute exercise bout at fixed work rate
what is steady state of physiological parameters
physiological parameters become stable for an extended amount of time
some exercise intensities or factors may prevent stea
True or False all constant work rate exercise is steady state
false
what is non-steady state of physiological parameters
whenever a parameter is systematically changing over time and always occur at the initial transition to a new work rate as it take time for physiological parameters such as HR and VO2 to reach steady state
What is function in exercise physiology
WHY something happens
- HR increases to deliver more O2 to working muscle
What is mechanism in exercise physiology
HOW something happens
HR increased through parasympathetic withdrawl and increased sympathetic nerve activity
What is energy
the capacity to do work measured in J and cal
- humans convert PE (food) into chemical, cellular, and mechanical work
What is mechanical work
Mechanical work = foce * distnace measured in J, kcal, kilopond-meters, kilogram meters
How much work (J) does it take to lift a 10kg weight a distance of 2 meters
Mechanical work = force * distance
force = mass * acceleration = 10kg *9.81m/s^2 = 98.1 N
distance = 2 meters
Mechanical work = 98.1N * 2m = 196.2 J
How much work (kgm or kpm) does it take to lift a 10kg weight a distance of 2 meters
mechanical energy = force * distance
force = 10kg
distance = 2m
1kgm=1kpm
mechanical energy = 10kg *2 meters = 2kgm = 20 kpm
What is power and what is the equation associated with it and units
Power = work rate = work (J) / time (sec)
measured in Watts, kcal/min, kgm/min
How much power (W) does it take to perform 20,000 joules of work in 60 seconds
Power = work / time
time = 60 seconds
Work = 20,000 J
1 watt = 1J/s
power = 20,000J/60 sec =333.33 J/s = 333.33 W
A stationary cycle allows accurate measurement of what?
accurate measurement of work performed; friction based; 6 m/rev
Using 1.5kg (14.7N) resistance, 6m/rev, and 60 rev/min for 10 minutes of exercise determine total work and total power
Total Work: force * distance
14.7 N * (6m/rev * 60 rev/min * 10 minutes) = 52,920 J total work
OR 1.5kg * (6m/rev * 60 rev/min * 10 minutes) = 5400 kgm
Total Power: work / time
52,920 J / (10 minutes * 60 seconds) = 88.2 watts OR
5400 kgm / (10 minutes) = 540 kgm/min * (1W / 6kgm/min) = 90 W
How to quanitfy work on a treadmill
not easy to quantify work when treadmill is horizontal
work can be quantified with slope (% grade)
Ex. 60kg (588.6N) subject, 200m/min, 7.5% grade for 10 minutes Find work and power
Total Work: force * distance (vertical
588.6 N * (200m/min * 0.075 * 10 minutes) = 88290 J
Total Power: Work / time
88290 J / (60 seconds* 10 minutes) = 147.15 W
Oxygen consumption will always be expressed as what
expressed as a rate
VO2 = rate of oxygen consumption
What is the graded exercise test (GXT)
in GXT work rate is changing and is often the independent variable
dependent variable is usually VO2 and work rate is independent variable (x-axis)
VO2 max occurs at last point that VO2 increases and then plateaus
What is the contant work rate exercise test
when work rate is constant == time is usually independent variable
- when work is constant
What is the resting rate of oxygen consumption parameters for relative and absolute
absolute: 0.25 L/min
relative: 3.5 mL/kg/min
What is the peak power output on the bicycle parameters for relative and absolute
absolute: 1000 W
Relative: 12.0 W/kg
what is a relative value
adjusting the value to a common scale (body mass)
Which athlete has a greater aerobic capacity
1. 100kg athlete with absolute: VO2max = 5.0 L/min
2. 50kg athlete with absolute: VO2max = 3.0 L/min
- 5L /min * 1000ml/L * 100kg = 50mL/kgmin
2 3L/min * 1000ml/L * 50kg = 60mL/kgmin
what are the units for relative oxygen consumption
ml/kg/min = ml/min/kg= mlkg-1min-1
What are the absolute vs relative intensity of power output
absolute: 100W or 150 beat/min
relative: 50%peak power or 50% max HR
Who is exercising at a greater relative intensity
1. 85 year old male: Max HR = 150beats/min
2. 40 year old male: Max HR = 180 beats/min
both are told to exercise at 140 beats/min
the 85 year old male because his relative intensity would be 140bpm/150 bpm = 93% of max HR which is higher tthan the 40 year old male who’s relative intentisty is 140/180 = 78% of max HR
Do people with higher or lower VO2 max (%) have a higher blood lactate
people with lower VO2 max (%)
A (1) Watt is equal to how many kpm/min
about 6kpm/min
In a graded exercise test what are the usual dependent and independent variables
work rate = independent variable (x-axis)
VO2 = dependent variable (y-axis)
what is the independent variable in a constant work rate exercise test
time
%VO2 max is what type of power
relative aerobic power
