Chapter 5 - Adaptations to Anaerobic Training Programs

Hormonal Markers of Anaerobic Overtraining

Acute epinephrine and norepinephrine increases beyond normal exercise induced level (sympathetic overtraining system)

Neural Adaptations with heavy resistance training - order of muscle fiber recruitment

All muscle fibers get large (hypertrophy) because they are all recruited in consecutive order by their size to produce high levels of force. In advanced lifters, the central nervous system might adapt by allowing these athletes to recruit some motor units not in consecutive order, recruiting larger ones first to help with greater production of power or speed in a movement.

Flexibility

Anaerboic training potentially can have a positive impact on flexibility, primarily if the individual has poor flexibility to begin with -The combination of resistance training and stretching appears to be the most effect method to improve flexibility with increasing muscle mass

Things resistance training decreases

Decreases: Mitochondrial Density Capillary density % of body fat

Things that resistance training decreases or no change:

Decreases: Mitochondrial Density Decreases or no change: Capillary density

Anaerobic Training

High-intensity, intermittent bouts of exercise

Process of Hypertrophy

Increase in synthesis of contractile proteins actin and myosin within myofibril and increase in number of myofibrils within a muscle fiber. New myofilaments added to external layers of myofibril resulting in increase in diameter

How can athletes stimulate connective tissue adaptations? For tendons, ligaments, and fascia:

Long-term adaptations in tendons, ligaments, and fascia are stimulated through progressive high-intensity loading patterns using external resistances -High-intensity loads should be used, as low to moderate intensities do not markedly change the collagen content of connective tissue. -Forces should be exerted throughout the full range of motion of a joint, and wherever possible multiple-joint exercises should be used.

Detraining continuted

Magnitude of these losses is dependent on the length of the detraining period as well as the initial training status of the individual

Adaptations of Motor Units

Maximal strength and power increases of agonist muscles result from an increase in recruitment, rate of firing, synchronization of firing, or a combination of these factors.

Anaerobic training and Bone growth

Muscle strength and hypertrophy gains increase the force exerted on the bones, which may result in a corresponding increase in bone mineral density (BMD) or the quantity of mineral deposited in a given area of bone.

Physiological Adaptations to Resistance Training Things that it increases:

Musuclar Stregth Muscular Endurance Maximizal rate of force production Vertical jump Anaerobic power Sprint speed Fiber size Stored ATP Stored Creatine Phosphate Stored Glycogen % of fat free mass No change or increase slightly: Aerobic Power

Excessive training on a short-term basis is called

Overreaching

Markers of Anaerobic Overtraining

Psychological effects: decreased desire to train, decreased joy from training -Acute epinephrine and norephinephrine increases beyond normal exercise-induced levels (sympathetic overtraining syndrome) -Performance decrements, although these occur too late to be a good predictor

Hormone receptor changes

Resistance training has been shown to upregulate androgen receptor content within 48 to 72 hours after the workout.

Connective Tissue Adaptations: General Bone Physiology

Trabecular bone responds more rapidly to stimuli than does cortical bone -Minimal essential strain (MES) is the threshold stimulus that initiates new bone formation -The MES is approximately 1/10 of the force required to fracture bone -Forces that reach or exceed a threshold stimulus intiaite new bone formation in the area experiencing the mechanical strain

Type 1 vs Type II collagen fibers for different types of connective tissue

Type 1 for bone, tendon, and ligaments Type 2 for cartilage

Ventilatory Response to Anaerobic Exercise

Ventilation generally does not limit resistance exercise and is either unaffected or only moderately improved by anaerobic training.

Detraining

decrement in performance and loss of accumulated physiological adaptations following the cessation of anaerobic training or when there is a substantial reduction in frequency, volume, intensity, or any combination of these.

Detraining in highly trained athletes

eccentric force and sport-specific power may decline significantly faster

Bone Modeling

(a) Application of a longitudinal weight-bearing force causes the bone to bend, creating a stimulus for new bone formation at the regions experiencing the greatest deformation. (b) Osteoblasts lay down additional collagen fibers. (c) Previously dormant osteoblasts migrate to the area experiencing the strain. (d) The collagen fibers become mineralized, and the bone diameter effectively increases.

Cardiovascular and Respiratory Responses to Acute Exercise Acute Cardiovascular responses to anaerobic exercise

-An acute bout of anaerobic exercise signficantly increases the cardiovascular responses, especially if the individual uses the Valsalva maneuver -Acute anaerobic exercise results in increased cardiac output, stroke volume, heart rate, oxygen uptake, systolic blood pressure, and blood flow to active muscles.

Anaerobic Training and Electromyography (EMG) Studies

-An increase in EMG indicated greater neural activiation -Studies have shown stregth and power increases of up to 73% -Advancement in training contributes to further gains in strength and power -Dramatic increases in neural adaptations take place early in the training program

Specific tendinous changes that contribute to size and strength increases include:

-An increase in collagen fibril diameter -A greater number of covalent cross-links within the hypertrophied fiber -An increase in the number of collagen fibrils -An increase in the packing density of collagen fibrils

Chronic Cardiovascular Adaptations at Rest

-Anaerobic training leads to decreases or no change in resting HR and BP. -Resistance training alters cardiac dimensions.

Sites where connective tissues can increase strength and load-bearing capacity are:

-At the junctions between the tendon (and ligament) and bone surface, -Within the body of the tendon or ligament and -In the network of fascia within skeletal muscle

Mistakes that can lead to anaerobic overtraining

-Chronic use of high intensity of high volume or a combination of the two -Too rapid a rate of progression

Compatibility of Aerobic and Anaerobic Modes of Training

-Combining resistance and aerobic endurance training may interfere with strength and power gains primarily if the aerobic endurance training is high in intensity, volume, and frequency. -No adverse effects on aerobic power result from heavy resistance exercise.

Aerobic Capacity (heavy resistance's effect on it)

-Heavy resistance training does not significantly affect aerobic capacity unless the individual is initially deconditioned -The exception is in relatively untrained people, who can experience increases in VO2max ranging from 5-8% as a result of resistance training -Circuit training and programs using high volume and short rest peroids (i.e. 30 sec or less) have been shown to improve VO2 max.

Power

-Heavy resistance training with slow velocities of movement leads primarily to improvements in maximal strength, whereas power training (i.e. lifting light-to-moderate loads at high velocities) increases force output at higher velocities and rate of force development. -Peak power output is maximized during the jump squat with loads corresponding to 30% to 60% of squat 1 RM. -For the upper body, peak power output can be maximized during the ballistic bench press throw using loads corresponding to 46% to 62% of 1RM bench press

Neuromuscular Junction Possible changes with anaerobic training include:

-Increased area of neuromuscular junction (NMJ) -More dispersed, irregularly shaped synapses and a greater total length of nerve terminal branching -Increased end-plate perimeter length and area, as well as greater dispersion of acetylcholine receptors within the end-plate region

Principles of training to increase bone stregth

-Magnitude of the load (intensity) -Rate (speed) of loading -Direction of the forces -Volume of loading (number of reps)

How can athletes stimulate connective tissue adaptations? For cartilage:

-Moderate-intensity anaerobic exercise seems to be adequate for increasing cartilage thickness. Strenuous exercise does not appear to cause any degenerative joint disease when progressively overloaded appropriately -Tissue viability can be maintained by adopting a variety of exercise modalities and ensuring that load is applied throughout the range of motion

Muscular Growth

-Muscle hypertrophy refers to muscular enlargement from an increase in the cross-sectional area of the existing fibers. -Hyperplasia results in an increase in the number of muscle fibers via longitudinal fiber splitting.

Cartilage adaptations to anaerobic training First, what are the main functions of cartilage?

-Provide a smooth joint articulating surface -Act as a shock absorber for forces directed through the joint -Aid in the attachment of connective tissue to the skeleton

Other Muscular Adaptations

-Reduced mitochondrial density -Decreased capillary density -Increased buffering capacity (acid-base balance) -Changes in muscle substrate content and enzyme activity

Body Composition

-Resistance training can increase fat-free mass and reduce body fat by 1% to 9% -Incrases in lean tissue mass, daily metabolic rate, and energy expenditure during exercise are outcomes of resistance training

Structural and architectural changes

-Resistance training increases myofibrillar volume, cytoplasmic density, sarcoplasmic reticulum and T-tubule density, and sodium-potassium ATPase activity. -Sprint training enhances calcium release. -Resistance training increases angle of pennation.

Endocrine responses and adaptations to anaerobic training: Acute Anabolic hormonal responses

-The acute anabolic hormonal response to anaerobic exercise is critical for exercise performance and subsequent training adaptations -Upregulation of anabolic hormone receptors is important for mediating the hormonal effects

Adaptations of tendons, ligaments, and fascia to anaerobic training

-The primary stimulus for growth of tendons, ligaments, and fascia is the mechanical forces created during exercise -The degree of tissue adaptation is proportional to the intensity of exercise -Consistent anaerobic exercise that exceeds the threshold of strain stimulates connective tissue changes

How can athletes stimulate bone formation?

-Use exercises that directly load particular regions of the skeleton. -Use structural exercises to direct force vectors through the spine and hip and allow the use of greater absolute loads in training. -Overload the musculoskeletal system and progressively increase the load as the tissues become accustomed to the stimulus. -Vary exercise selection to change the distribution of the force vectors to continually present a unique stimulus. -The exercises should be weight bearing

The next 10 slides are the "improvements in performance from anaerobic exercise" Muscular Strength:

A review of more than 100 studies showed that mean strength increased approximately 40% in "untrained" 20% in "moderately trained" 16% in "trained" 10% in "advanced: 2% in "elite" participants over periods ranging from four weeks to two years -Heavier loads are most effective for fiber recruitment -The effects of training are related to the type of exercise used, its intensity, and it volume

Motor Performance

Anaerobic training enhances motor performance; the magnitude of change is based on the specificity of the exercises or modalities performed. Resistance training has been shown to increase: Running economy Vertical jump Sprint speed Tennis serve velocity Swinging and throwing velocity Kicking performance

Neural Adaptations

Anaerobic training may elicit adaptations along the neuromuscular chain, beginning in the higher brain centers and continuing down to the level of individual muscle fibers.

Neuromuscular Reflex Potentiation

Anaerobic training may enhance the reflex response, thereby enhancing the magnitude and rate of force development.

Cartilage adaptations to anaerobic training

Cartilage lacks its own blood supply and must depend on diffusion of oxygen and nutrients from synovial fluid. Therefore, joint mobility is linked with joint health. Movement about a joint creates changes in pressure in the joint capsule that drive nutrients from the synovial fluid toward the articular cartilage of the joint.

Central adaptations vs Adaptations of motor units

Central: -Motor cortex activity increases when the level of force developed increases and when new exercises or movements are being learned -Many neural changes with anaerobic training take place along the descending corticospinal tracts

Chronic Adaptations of the Acute cardiovascular Response to Anaerobic Exercise

Chronic resistance training reduced the cardio-vascular response to an acute bout of resistance exercise of a given absolute intensity or workload

The primary structural component of all connective tissue is:

Collagen fiber

Chronic changes in resting hormonal concentrations

Consistent chronic changes in resting hormonal concentrations are less likely.

Chronic changes in the acute hormonal response

Consistent resistance training may improve the acute hormonal response to an anaerobic workout.

Fiber Type Transitions

Continuum of fiber types: I, Ic, IIc, IIac, IIa, IIax, IIx -Muscle fiber transitions occur during training -This means that a shift of the type of myosin adenosine triphatase (ATPase) and heavy chains takes place during training -Transformations from IIx to IIax to IIa can be seen, and then small percentages change to IIac and IIc -Exercise activites that recruit motor units with Type IIx muscle fibers initiate a shift toward IIa fibers

- Additional findings include the following: Cross-education

Cross-education: Muscle undergoing unilateral resistance training produces increased strength and neural activity in the contralateral resting muscle -Bilateral deficit in untrained individuals - the force produced when both limbs contract together is lower than the sum of the forces they produce when contracting unilaterally -Bilateral facilitation in trained or stronger individuals: an increase in voluntary activation of the agonist muscle groups occurs -Chagnes in muscle activity of the antagonists during agonist movements

Local muscular endurance

Cross-sectional data in anaerobic athletes have shown enhanced muscular endurance and subsequent muscular adaptations consistent with improved oxidative and buffering capacity -Skeletal muscle adaptations to anaerobic muscular endurance training include increased mitochondrial and capillary number, fiber type transitions, buffering capacity, resistance to fatigue, and metabolic enzyme activity.

Overtraining

Excessive frequency, volume, or intensity of training, resulting in fatigue, illness, or injury (which is also caused by a lack of proper rest and recovery and perhaps nutrient intake).

Size Principle of recruitment

Low-threshold motor units are recruited first and have lower force capabilities than higher-threshold motor units. -Typically to get to the high-threshold motor units, the body must first recruit the lower-threshold motor units. -Exceptions exist, especially with respect to explosive, ballistic contractions that can selectively recruit high-threshold units to rapidly achieve more force and power.

How does Anaerobic use ATP differently?

Requires ATP to be regenerated at a faster rate than the areobic energy system is capable of -Includes the anaerboic alactic system (also known as the phosphagen or creatine phosphate system) -Anaerobic lactic system (also known as the glycolytic system)

Fiber Size Changes

Resistance training results in increases in both Type I and Type II muscle fiber area. Type II fibers have greater increases in size than Type I fibers

Muscular Adaptations

Skeletal muscle adapts to anaerobic training primarily by increasing its size, facilitating fiber type transitions, and enhancing its biochemical and ultra-structural components. These changes result in enhanced muscular strength, power, and muscular endurance. These are all about to be explained individually...

Muscle fiber cross-sectional area declines rapidly in

strength and sprint athletes -these changes specifically targeted fast-twitch fibers initially, with no significant change immediately found in the slow-twitch fiber population

-oxidative fibers may increase in strength-trained athletes (decrease in endurance athletes)

within 8 weeks of stopped training