This document discusses various aspects of muscle physiology and training principles. It defines key terms like muscle strength, power, endurance and different energy systems. It describes how muscle adaptations occur in response to different types of training like resistance, aerobic and anaerobic training. It also summarizes the cardiovascular, respiratory, muscular and other physiological adaptations that result from endurance training.

2.  Muscle Strength
 Maximal force that a muscle or muscle group can generate.
 Muscle Power
 Rate of the performing muscle, thus the product of the force
and velocity.
 Explosive aspect of strength, the product of strength and
speed of movement.
 Power = Force X Distance / Time
 Where (force = strength) and (distance/ Time = speed)

3. POWER = SPEED X STRENGTH
Power can be developed by:-
RESISTANCE
RUNNING
HILL RUNNING
PLYOMETRICS

4.  Muscular Endurance
 The capacity to sustain repeated muscular contractions or a
single static contraction.
 Aerobic Power
 Rate of energy release by cellular metabolic processes that
depend upon the availability and involvement of oxygen.
 Maximal aerobic power refers to the maximal capacity for
aerobic resynthesis of ATP.
 Equivalent to aerobic capacity and maximal oxygen uptake
(VO2max).
 Best lab test is a graded exercise test to exhaustion.

5.  Anaerobic Power
 Rate of energy release by cellular metabolic processes that
function without the involvement of oxygen.
 Maximum anaerobic power / anaerobic capacity – maximal
capacity for the anaerobic system to produce ATP
 Tests: None universally accepted
 Critical Power Test
 Wingate anaerobic Test

8. Principle of Individuality
 No two individuals have exactly the same genetic
characteristics (except for identical twins).
 Many factors contribute to variations in training responses
among individuals:
 Heredity
 Relative Fitness Level
 Cellular Growth Rate
 Metabolism
 Cardiovascular and Respiratory regulation
 Neural and Endocrine regulation

9. Principle of Specificity
 Exercise response is specific to the mode and intensity of
exercise.
 The training program must stress the physiological systems
that are critical for optimal performance in the given sport to
achieve specific training adaptations.
 Specific exercise elicits specific adaptations, creating specific
effects (Specific Adaptations to Imposed Demands
principle).

10. Principle of Reversibility
 Detraining causes measurable reductions in physiological
functions and exercise capacity.
 Reversal of improvements gained through
training, decreasing to a level that meets the demands of
ADLs.
 Training program must include a maintenance plan.

11. Principle of Progressive
Overload
 Overload and progressive training form the foundation of
all training.
 Exercising @ intensities greater than normal induces a
variety of highly specific adaptations that enables the body
to function more efficiently.
 Achieving the appropriate overload requires manipulating
combinations of training:
 Frequency
 Intensity
 Duration
 Exercise Mode

12. Principle of Hard/Easy
 Training Hard
 Training each day @ high intensities or for long durations or
both.
 Training Easy
 Provides a day active recovery so that the body is prepared for
future hard training.

13. Principle of Periodization
 Periodization is the gradual cycling of
specificity, intensity, and volume of training to achieve peak
levels of fitness for competition.
 Macrocycle
 Mesocycle
 Preparation
 Competition
 Transition
 Microcycle

15. Training Needs Analysis
 Should include the following assessment:
 What major muscle groups need to be trained?
 What type of training should be used?
 What energy system should be stressed?
 What are the primary sites of concern for injury prevention?

16.  Prescriptions should entail:
 Exercises to be performed.
 Order in which they will be performed.
 Number of sets for each exercise.
 Rest period for between each set and between exercises.
 Intensity or load.
 Number of repetitions.
 Velocity of movement to be used.

17. Selecting the Appropriate
Resistance and Repetitions
 The resistance to be used is generally expressed as a percentage of
the maximal capacity.
 Strength development is optimized by moderate to high resistance
(60 – 80% of 1RM) with low to moderate repetitions (6- 12 reps).
 Muscular endurance is optimized by low to moderate resistance
(30 – 70% of the 1RM) and moderate to high repetitions (10 – 25
reps).
 Power is optimized by alternating low to moderate resistance (30 –
60% of 1 RM) and low repetition (3 – 6 reps) at an explosive
velocity with the traditional strength training recommendations.

18.  To hypertrophy muscle – moderate to high resistance (70 –
100% 1RM) with low to moderate repetition (1 – 12 reps)

19. Selecting the Appropriate
Number of Sets
 Single set versus multiple sets.
 Single set used for untrained persons or those needing to
maintain a basic level of muscular fitness and not interested
in further improvements.
 Multiple sets used for additional gains in:
 Strength
 Endurance
 Power
 Hypertrophy

21. Periodization
 Refers to changes or variations in the resistance program
that are implemented over the course of a specific period of
time (eg. a year).
 It varies the exercise stimulus to keep the individual from
overtraining or becoming stale.

22.  Two forms of periodization:
 Classic Strength and Power Periodization
 Undulating Periodization

23.  Classic Strength and Power Periodization
 Consists of 5 phases in each training cycle.
 Phase I
 High volume with low intensity
 Phase II, III, and IV
 Volume decreased with increasing intensity.
 Phase V (active recovery phase)
 Either light resistance training or some unrelated activity is
allowed to allow the person time to recover from the training
cycle both physically and mentally.

24. Periodization for Resistance Training (1 year,5 phases)
Phase I Muscular hypertrophy
High volume
Phase II Strength
intensity
Phase III Power
Phase IV Peak strength
Phase V Active recovery

26.  Undulating Periodization
 Has more variations to accommodate the unique demands of
each sport.

27. Resistance Training
 Types of Resistance Training
 Isometric Training
 Facilitate recovery and reduce muscle atrophy and strength loss
 Free Weights
 Resistance used is limited by the weakest point in the range of
motion.
 More motor recruitment
 Gain control of the free weight
 Stabilize the weight
 Maintain body balance

28. Variation in Strength Relative to the Angle of
the Elbow During the Two-Arm Curl

29.  Eccentric Training
 Maximize gains in strength and size
 Variable Resistance Training
 Resistance reduced at weakest points and increased at strongest
points.
 Isokinetic Training
 Motion speed is kept constant throughout.
 Contract at maximal force at all points in the range of motion (if
properly motivated).

30. A Variable-Resistance Training
Device
© Human Kinetics

31.  Plyometrics / Stretch Shortening Cycle Exercises
 Proposed to bridge the gap between speed and strength training.
 Utilizes the stretch reflex to facilitate recruitment of motor units.
 Stores energy in the elastic and contractile components of muscle
during the eccentric contraction (stretch) that can be recovered
during the concentric contraction
 Electrical Stimulation Training
 Reduce loss of strength and muscle size

32. Plyometric Box Jumping

33. Resistance Training
Programs
Key Points
 Low-repetition, high-resistance training enhances strength
development
 High-repetition, low-resistance training optimizes muscular
endurance
 Periodization is important to prevent overtraining and
burnout
 A typical periodization cycle has 4 active phases, each
emphasizing a different muscular fitness component, plus
an active recovery
(continued)

34. Resistance Training Programs
(continued)
Key Points
 Resistance training can use static or dynamic
contractions
 Eccentric training appears to be essential to
maximizing hypertrophy
 Electrical stimulation can be successfully used in
rehabilitating athletes

35. Adaptations to Resistance
Training
 Increased motor unit
recruitment
 Coordination of motor unit
recruitment (synchronous)
 Rate Coding: firing
frequency of the motor units
 Decreased autogenic
inhibition
 Decreased sensitivity of
the golgi tendon organs to
tension
 may lead to injury

36. Adaptations to Resistance
Training
 Chronic Hypertrophy
 Relates to increase in muscle size that occurs with long term
resistance training.
 Fiber hypertrophy
 Myofibrils
 Actin and Myosin filaments
 Sarcoplasm
 Connective tissue
 Fiber hyperplasia

37. Adaptations to Resistance
Training
 Transient Hypertrophy
 Due to increased blood flow to the muscles during exercise.
 Fluid accumulation in the interstitial and extracellular spaces that
comes from the blood plasma.
 Lasts for a short time, as fluid returns to the blood within hours
after exercise.

38. Adaptations to Resistance
Training
 Fiber Type Alterations
 muscle fibers begin to take
on certain characteristics of
the opposite fiber type after
opposing training occurs.
 chronic stimulation of FT
motor units with low
frequency nerve stimulation
transforms FT motor units
into ST motor units within a
matter of weeks!
 extreme, prolonged training
may produce skeletal muscle
fiber type conversion.

39. Muscular Response to
Resistance Training
 Acute Muscle Soreness
 Pain felt immediately after exercise
 accumulation of H+
 Lactate
 tissue edema
 Disappears minutes
to hours after training.

40. Muscular Response to
Resistance Training
 Delayed Onset Muscle Soreness
 muscle and connective tissue damage
 inflammation (macrophages, white blood cells)
 increased chemical mediators (bradykinin)
 Edema

41. DOMS & Performance
 Reduction in force generating
capacity of the muscle.
 Loss of strength due to:
 Physical disruption of the
muscle.
 Failure within the excitation –
contraction coupling process.
 Loss of contractile protein.
 Muscle glycogen resynthesis is
also impaired with muscle
damage.

43. Aerobic and Anaerobic
Training
Aerobic (endurance) training
 Improved central and peripheral blood flow
• Enhances the capacity of muscle fibers to generate
ATP
Anaerobic training
• Increased short-term, high-intensity endurance
capacity
• Increased anaerobic metabolic function
• Increased tolerance for acid–base imbalances during
highly intense effort

44. Endurance
Muscular endurance: the ability of a single muscle or
muscle group to sustain high-intensity repetitive or
static exercise
Cardiorespiratory endurance: the entire body’s
ability to sustain prolonged, dynamic exercise using
large muscle groups

45. Evaluating Cardiorespiratory
Endurance
VO2max
• Highest rate of oxygen consumption attainable
during maximal exercise
• VO2max can be increased by 10-15% with 20 weeks
of endurance training
.
.

46. Increases in VO2max
With Endurance Training
Fick equation:
VO2 = SV HR (a-v)O2 diff
.

47. Changes in VO2max With 12 Months
of Endurance Training
.

48. Cardiovascular Adaptation
to Training
• Heart size
• Stroke volume
• Heart rate
• Cardiac output
• Blood flow
• Blood pressure
• Blood volume

49. Heart Size (Central) Adaptation
to Endurance Training
 Cardiac Hypertrophy / Athlete’s heart
• The left ventricle changes significantly in response
to endurance training
• The internal dimensions of the left ventricle
increase as an adaptation to an increase in
ventricular filling secondary to an increase in
plasma volume and diastolic filling time
• Left ventricular wall thickness and mass
increase, allowing for greater contractility

50. Measuring Heart Size:
Echocardiography
© Tom Roberts

51. Percentage Differences in Heart Size
Among Three Groups of Athletes
Compared With Untrained Group

52. Changes in Stroke Volume
With Endurance Training

54. Stroke Volume Adaptations
to Endurance Training
Key Points
• Endurance training increases SV at rest and
during submaximal and maximal exercise
• Increases in end-diastolic volume, caused by an
increase in blood plasma and greater diastolic
filling time (lower heart rate), contribute to
increased SV
• Increased ventricular filling (preload) leads to
greater contractility (Frank-Starling mechanism)
• Reduced systemic vascular resistance (afterload)

55. Heart Rate Adaptations
to Endurance Training
Resting
 Decreases by ~1 beat/min with each week of training
 Increased parasympathetic (vagal) tone
Submaximal
• Decreases heart rate for a given absolute exercise intensity
Maximal
• Unchanged or decreases slightly

56. Changes in Heart Rate
With Endurance Training

57. Heart Rate Recovery
• The time it takes the heart to return to its resting rate
after exercise
• Faster rate of recovery after training
• Indirect index of cardiorespiratory fitness
• Prolonged by certain environments (heat, altitude)
• Can be used as a tool to track the progress of
endurance training

58. Changes in Heart Rate Recovery
With Endurance Training

59. Cardiac Output Adaptations
to Endurance Training
Q = HR x SV
 Does not change at rest or during submaximal exercise
(may decrease slightly)
 Maximal cardiac output increases due largely to an
increase in stroke volume
.

60. Changes in Cardiac Output
With Endurance Training

61. Cardiac Output Adaptations
Key Points
• Q does not change at rest or during submaximal
exercise after training (may decrease slightly)
• Q increases at maximal exercise and is largely
responsible for the increase in VO2max
• Increased maximal Q results from the increase in
maximal SV
.
.
.
.

62. Blood Flow Adaptations
to Endurance Training
Blood flow to exercising muscle is increased with
endurance training due to:
• Increased capillarization of trained muscles
• Greater recruitment of existing capillaries in trained muscles
• More effective blood flow redistribution from inactive regions
• Increased blood volume
• Increased Q
.

64. Blood Pressure (BP) Adaptations
to Endurance Training
 Resting BP decreases in borderline and hypertensive
individuals (6-7 mmHg reduction)
 Mean arterial pressure is reduced at a given
submaximal exercise intensity (↓ SBP, ↓ DBP)
 At maximal exercise (↑ SBP, ↓ DBP)

65. Blood Volume (BV) Adaptations
to Endurance Training
 BV increases rapidly with endurance training
 Plasma volume increases due to:
 Increased plasma proteins (albumin)
 Increased antidiuretic hormone and aldosterone
 Red blood cell volume increases

66. Increases in Total Blood Volume and Plasma
Volume With Endurance Training

67. Blood Flow, Pressure, and Volume
Adaptations to Endurance Training
Key Points
• Blood flow to active muscles is increased due to:
– ↑ Capillarization
– ↑ Capillary recruitment
– More effective redistribution
– ↑ Blood volume
• Blood pressure at rest as well as during
submaximal exercise is reduced, but not at
maximal exercise
(continued)

68. Blood Flow, Pressure, and Volume
Adaptations to Endurance Training
(continued)
Key Points
• Blood volume increases
• Plasma volume increases through increased protein
content and by fluid conservation hormones
• Red blood cell volume and hemoglobin increase
• Blood viscosity decreases due to the increase in plasma
volume

69. Respiratory Adaptations
to Endurance Training
Key Points
• Little effect on lung structure and function at rest
• Increase in pulmonary ventilation during maximal
exercise
• ↑ Tidal volume
• ↑ Respiratory rate
• Pulmonary diffusion increases at maximal exercise due
to increased ventilation and lung perfusion
• (a-v)O2 difference increases with training, reflecting
increased extraction of oxygen at the tissues

70. Adaptations in Muscle
to Endurance Training
• Increased size (cross-sectional area) of type I fibers
• Transition of type IIx → type IIa fiber characteristics
• Transition of type II → type I fiber characteristics
• Increased number of capillaries per muscle fiber and for a
given cross-sectional area of muscle
• Increased myoglobin content of muscle by 75% to 80%
• Increased number, size, and oxidative enzyme activity of
mitochondria

71. Change in Maximal Oxygen Uptake and
SDH Activity With Endurance Training

72. Gastrocnemius Oxidative Enzyme Activities
of Untrained (UT) Subjects, Moderately
Trained (MT) Joggers,
and Highly Trained (HT) Runners
Adapted, by permission, from D.L. Costill et al., 1979, "Lipid metabolism in skeletal muscle of endurance-trained
males and females," Journal of Applied Physiology 28: 251-255 and from D.L. Costill et al., 1979, "Adaptations in
skeletal muscle following strength training," Journal of Applied Physiology 46: 96-99.

73. Adaptations in Muscle With
Training
Key Points
 Type I fibers tend to enlarge
 Increase in type I fibers and a transition from type IIx to type
IIa fibers
 Increased number of capillaries supplying each muscle fiber
 Increase in the number and size of muscle fiber mitochondria
 Oxidative enzyme activity increases
 Increased capacity of oxidative metabolism

74. Metabolic Adaptations to
Training
 Lactate threshold increases due to:
– Increased clearance and/or decreased production of
lactate
– Reduced reliance on glycolytic systems
 Respiratory exchange ratio decreases due to:
– Increased utilization of free fatty acids
 Oxygen consumption (VO2)
– Unchanged (or slightly reduced) at submaximal intensities
– VO2max increases
– Limited by the ability of the cardiovascular system to
deliver oxygen to active muscles
.
.

75. Changes in Lactate Threshold
With Training

78. Changes in Race Pace With Continued
Training After VO2max Stops Increasing
.

79. Increased Performance
After VO2max Has Peaked
 Once an athlete has achieved their genetically
determined peak VO2max, they can still increase their
endurance performance due to the body’s ability to
perform at increasingly higher percentages of that
VO2max for extended periods. The increase in
performance without an increase in VO2max is a result
of an increase in lactate threshold.
.
.
.
.

80. Factors Affecting VO2max
 Level of conditioning: Initial state of conditioning will
determine how much VO2max will increase (i.e., the
higher the initial value, the smaller the expected
increase)
 Heredity: Accounts for 25-50% of the variation in
VO2max
 Sex: Women have lower VO2max compared to men
 Individual responsiveness: There are high responders
and low responders to endurance training, which is a
genetic phenomenon
.
.
.
.

83. Cardiorespiratory Endurance
and Performance
• It is the major defense against fatigue
• Should be the primary emphasis of training for health
and fitness
• All athletes can benefit from maximizing their
endurance

84. Adaptations to Aerobic Training
Key Points
• Although VO2max has an upper limit, endurance
performance can continue to improve
• An individual’s genetic makeup predetermines a range for
his or her VO2max and accounts for 25-50% of the variance
in VO2max
• Heredity largely explains an individual’s response to
training
• Highly conditioned female endurance athletes have
VO2max values about 10% lower than their male
counterparts
• All athletes can benefit from maximizing their
cardiorespiratory endurance
.
.
.
.

85. Summary of Cardiovascular Adaptation
to Chronic Endurance Training

86. Muscle Adaptations
to Anaerobic Training
• Increased muscle fiber recruitment
• Increased cross-sectional area of type IIa and type IIx
muscle fibers

87. Energy System Adaptations
to Anaerobic Training
 Increased ATP-PCr system enzyme activity
 Increased activity of several key glycolytic enzymes
 No effect on oxidative enzyme activity

88. Anaerobic Training
Key Points
 Anaerobic training bouts improve both anaerobic
power and anaerobic capacity
 Increased performance with anaerobic training is
attributed to strength gains
 Increases ATP-PCr and glycolytic enzymes