active vs. passive recovery recovery after exercise is associated with reduction of blood lactate...
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Active vs. Passive Recovery
• Recovery after exercise is associated with reduction of blood lactate concentration
• Active recovery (low intensity aerobic exercise) reduces recovery time compared to passive recovery
• During active recovery, blood flow to the active muscles remains high
• Since the energy consumption during active recovery remains high, the use of lactate as an energy source is higher compared to passive recovery
Active vs. Passive Recovery
• Recovery after exercise is associated with reduction of blood lactate concentration
• Active recovery (low intensity aerobic exercise) reduces recovery time compared to passive recovery
• During active recovery, blood flow to the active muscles remains high
• Since the energy consumption during active recovery remains high, the use of lactate as an energy source is higher compared to passive recovery
Economy of Movement and Mechanical Efficiency in Exercise
• Efficiency- the relation between input and resulting output
• The quantity of energy required to perform
a particular task in relation to the actual work accomplished
• Economy of physical effort
Economy
Mechanical / biomechanical efficiency Environmental factors
Mechanical Efficiency
Actual mechanical work accomplished Mechanical efficiency)%(
Input of energy= x 100
=kgm
VO2
x 100
=השקעה
תפוקה
Mechanical Efficiency
Example:
- 13,300 kgm of work were generated during 15 minute ride on a stationary bicycle.
-Total oxygen consumption 25 liters.
Mechanical efficiency calculation:
Energy input:25 liter of oxygen x 5kcal = 125 kcal
1 kcal = 426 kgm125 x 426 = 53,250 kgm
Mechanical efficiency
=13,300 kgm
53,250 kgmX 100 =24.9%
Efficiency of the Human Body
• The efficiency of human locomotion in walking, running and cycling ranges between 20-30%
• 20-30% of energy consumption is converted to mechanical work and 70-80% is converted directly to heat
• During rest 97% of energy consumption is converted directly to heat
Muscle Profile
Muscle Fiber Types
Motor Units
Number of muscle fibers
Types of muscle fibers
Muscle Fiber Types
Characteristics of the Three Muscle Fiber Types
Fiber TypeSlow Twitch (ST(Fast Twitch A (FT-A(Fast Twitch B (FT-B(
Contraction timeSlowFastVery fast
Size of motor neuronSmallLargeVery large
Resistance to fatigueHighIntermediateLow
Activity used forAerobicLong term anaerobicShort term anaerobic
Force productionLowHighVery high
Mitochondrial density
HighIntermediateLow
Capillary densityHighIntermediateLow
Oxidative capacityHighIntermediateLow
Glycolytic capacityLowHighHigh
Major storage fuelTriglyceridesGlycogenCP, Glycogen
Distribution of Muscle Fiber Types
• Genetic association• In none active population 40- 50% ST• Long distance runners 50-90% ST• Short distance runners 30-55% ST• Weight lifters 40-60% ST• Muscle fiber type has only a moderate effect
on maximal performance
Can training Change Fiber Type?
Training a FT -fibered muscle for endurance will not increase the number of ST fibers, nor will training a ST-fibered muscle for strength and power increase the number of FT fibers. With the proper training, FT -B fibers can take on some of the endurance characteristics of FT -A fibers and FT -A fibers can take on some of the strength and power qualities of FT-B fibers. However, there is no inter-conversion of fibers. FT fibers cannot become ST fibers, or vice versa. What an athlete is born with is what he or she must live with.
Economy of Movement and Mechanical Efficiency in Exercise
• Efficiency- the relation between input and resulting output
• The quantity of energy required to perform
a particular task in relation to the actual work accomplished
• Economy of physical effort
Economy
Mechanical / biomechanical efficiency Environmental factors
Mechanical Efficiency
Actual mechanical work accomplished Mechanical efficiency)%(
Input of energy= x 100
=kgm
VO2
x 100
=השקעה
תפוקה
Mechanical Efficiency
Example:
- 13,300 kgm of work were generated during 15 minute ride on a stationary bicycle.
-Total oxygen consumption 25 liters.
Mechanical efficiency calculation:
Energy input:25 liter of oxygen x 5kcal = 125 kcal
1 kcal = 426 kgm125 x 426 = 53,250 kgm
Mechanical efficiency
=13,300 kgm
53,250 kgmX 100 =24.9%
Efficiency of the Human Body
• The efficiency of human locomotion in walking, running and cycling ranges between 20-30%
• 20-30% of energy consumption is converted to mechanical work and 70-80% is converted directly to heat
• During rest 97% of energy consumption is converted directly to heat
Muscle Profile
Muscle Fiber Types
Motor Units
Number of muscle fibers
Types of muscle fibers
Muscle Fiber Types
Characteristics of the Three Muscle Fiber Types
Fiber TypeSlow Twitch (ST(Fast Twitch A (FT-A(Fast Twitch B (FT-B(
Contraction timeSlowFastVery fast
Size of motor neuronSmallLargeVery large
Resistance to fatigueHighIntermediateLow
Activity used forAerobicLong term anaerobicShort term anaerobic
Force productionLowHighVery high
Mitochondrial density
HighIntermediateLow
Capillary densityHighIntermediateLow
Oxidative capacityHighIntermediateLow
Glycolytic capacityLowHighHigh
Major storage fuelTriglyceridesGlycogenCP, Glycogen
Distribution of Muscle Fiber Types
• Genetic association• In none active population 40- 50% ST• Long distance runners 50-90% ST• Short distance runners 30-55% ST• Weight lifters 40-60% ST• Muscle fiber type has only a moderate effect
on maximal performance
Can training Change Fiber Type?
Training a FT -fibered muscle for endurance will not increase the number of ST fibers, nor will training a ST-fibered muscle for strength and power increase the number of FT fibers. With the proper training, FT -B fibers can take on some of the endurance characteristics of FT -A fibers and FT -A fibers can take on some of the strength and power qualities of FT-B fibers. However, there is no inter-conversion of fibers. FT fibers cannot become ST fibers, or vice versa. What an athlete is born with is what he or she must live with.