Neuromuscular and Muscular Fitness
Primary function of skeletal muscle
What is conversion of electrical signal to mechanical movement?
Force-velocity curve
When you lift heavier weights, you can not move with as much velocity (and the opposite)
Three ATP synthesis pathways
ATP-PCr, glycolytic, oxidative
Difference between BMR and RMR
BMR: basal metabolic rate, needed to survive
RMR: resting metabolic rate, burned at rest. Based on activity level, muscle mass, EPOC, etc.
Gold standard for VO2max
Plateau in VO2 with increasing workload
EMG is normalized to this for accurate comparison
MVIC
Length-Tension relationship
Too much overlap, optimal overlap, and not enough overlap
Gold standard for Anaerobic power
Wingate
Define O2 deficit and EPOC
O2 deficit: anaerobic metabolism fills in until aerobic can catch up (steady state)
EPOC: excess post-exercise oxygen consumption
Supplemental VO2max criteria
RER > 1.1, RPE >17-18, HR +/- 10 bpm of max, 8-12 minutes, volitional exhaustion
Handgrip is a good tool for disease states because:
It does not change across life a lot unless disease progression is present
EPOC graph
A = O2 deficit
B = Steady state
C = EPOC
What system is used for "all out" exercise?
Also, how long does it last and how long to replenish?
ATP-PCr
3-15 seconds, 85% in 3 min, 100% in ~10 min
What are Nitrogen, O2, and CO2 levels in the air? What are they during exercise (expired)?
N = 79%, O2 = 20.93%, CO2 = 0.04%
N = 78.09%, O2 = 16%, CO2 = 4%
Anaerobic metabolism helping, cannot buffer anymore (lactate)
Three types of contractions and what happens to the muscle/force?
Isotonic--tension constant while length of muscle changes
Isometric--muscle length constant while tension varies
Isokinetic--muscle speed constant with constant resistance
Define RER and how it is calculated
Respiratory exchange ratio
VCO2/VO2
What system provides energy for 30 sec to 3 min? Is this aerobic or anaerobic?
Glycolytic, anaerobic (does not rely on O2)
Why is the Haldane transformation important (what DOES the body use and what does the body NOT use)?
DO use: FeO2 FeCO2
Do NOT use: FiN2
If someone is at 2 L/min O2, how many calories are they burning per min?
~10 calories (2 L/min O2 * 4.9 kcal/min)
The 3 components of troponin do this (TnT, TnI, TnC)
TnT binds with tropomyosin
TnC binds with Calcium
TnI binds with actin to inhibit crossbridge formation
VO2 = 1 L/min. How would we convert to relative if our participant weighs 72 kg?
1 L/min * 1000 mL / 72 kg
Difference between Type I, Type IIa, and Type IIx muscle fibers
(see powerpoint slide)
How indirect calorimetry works
Estimate of type and amount of substrate used (fat, CHOs) by the body based measured volume of air and expired gases
Describe a MET and how to get METs from VO2
Metabolic equivalent, 1 MET = rest
1 MET = 3.5 mL/kg/min