Transcript Active vs. 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
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
Mechanical / biomechanical efficiency
Economy
Environmental factors
Mechanical Efficiency
Mechanical efficiency (%) =
Actual mechanical work accomplished
Input of energy
kgm
=
x 100
VO2
‫תפוקה‬
=
‫השקעה‬
x 100
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 kgm
125 x 426 = 53,250 kgm
Mechanical
efficiency
13,300 kgm
=
X 100
53,250 kgm
= 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 Type
Slow Twitch (ST(
Fast Twitch A (FT-A(
Fast Twitch B (FT-B(
Contraction time
Slow
Fast
Very fast
Size of motor neuron Small
Large
Very large
Resistance to fatigue High
Intermediate
Low
Activity used for
Aerobic
Long term anaerobic
Short term anaerobic
Force production
Low
High
Very high
Mitochondrial
density
High
Intermediate
Low
Capillary density
High
Intermediate
Low
Oxidative capacity
High
Intermediate
Low
Glycolytic capacity
Low
High
High
Major storage fuel
Triglycerides
Glycogen
CP, 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 STfibered 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 interconversion 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
Mechanical / biomechanical efficiency
Economy
Environmental factors
Mechanical Efficiency
Mechanical efficiency (%) =
Actual mechanical work accomplished
Input of energy
kgm
=
x 100
VO2
‫תפוקה‬
=
‫השקעה‬
x 100
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 kgm
125 x 426 = 53,250 kgm
Mechanical
efficiency
13,300 kgm
=
X 100
53,250 kgm
= 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 Type
Slow Twitch (ST(
Fast Twitch A (FT-A(
Fast Twitch B (FT-B(
Contraction time
Slow
Fast
Very fast
Size of motor neuron Small
Large
Very large
Resistance to fatigue High
Intermediate
Low
Activity used for
Aerobic
Long term anaerobic
Short term anaerobic
Force production
Low
High
Very high
Mitochondrial
density
High
Intermediate
Low
Capillary density
High
Intermediate
Low
Oxidative capacity
High
Intermediate
Low
Glycolytic capacity
Low
High
High
Major storage fuel
Triglycerides
Glycogen
CP, 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 STfibered 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 interconversion 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.