Chapter 5 Shit Flashcards
What are adaptations of Anaerobic training?
-Increased agonist recruitment
-Improved neural firing rates
-Greater synchronization of timing and neural discharge
-Reduction of inhibitory mechanisms such as GTO activation
What is cross-education?
When you do a unilateral resistance exercise, the non working side receives increases in strength and neural activity from the movement. Sully taught you this in music
What is the bilateral deficit?
Bilateral deficit is when the sum of unilateral force production is greater than the sum of bilateral force production
What is bilateral facilitation?
Occurs in trained individuals, force produced with both limbs is greater than the sum of unilateral force production
How do motor units adapt to anaerobic training?
-Increased frequency of firing increases force production
-Increased synchronization of agonist, synergist, and antagonist muscles
-Increased activation and firing rate are primary motor unit adaptations to anaerobic training
-Heavy lifting results in hypertrophy of all muscle fibers due to the size principle
-Advanced lifters can selectively recruit type 2 fibers - allows “skipping over” the type 1 fiber recruitment associated with the size principle to rapidly generate force by immediately recruiting type 2 fibers
I.E. olympic weightlifters
What is the size principle?
Motor units are recruited based on recruitment threshold and firing rate (units are recruited from smallest to largest depending on the intensity)
How do smaller and larger muscles increase force production?
-Smaller increase contraction frequency
-Larger increase contraction frequency and increasing motor unit recruitment
How does the structure of a muscle change with anaerobic training?
-Pennation angle can increase which allows a greater protein deposition and CSA growth (resistance training can also do this)
-Fascicle length can also increase (sprint and jump training can increase vastus lateralis fascicle length)
-Increase in myofibrillar volume
-Increased cytoplasmic density
-Increased sarcoplasmic reticulum and T-tubule density
-Increased sodium-potassium ATPase activity
-Reduced mitochondrial density due to muscle CSA increase being greater than increase in mitochondria (not caused by loss of mitochondria)
-Reduced capillary density caused by increase in muscle CSA
-Increased H+ buffering capacity
-Increased resting CP and ATP concentration
-Increased muscle glycogen content
What are CNS adaptations to anaerobic training?
-Neural changes in spinal cord elevate fast-twitch recruitment
-Untrained populations have limited ability for maximal recruitment
-Less than 71% of muscle tissue activated during max effort in untrained people
How does the neuromuscular junction and reflex potentiation adapt to anaerobic training?
Adaptations in the NMJ include an increased area of NMJ and greater length of terminal nerve branches
Anaerobic training can increase the intensity of myotatic reflex - enhances the involuntary elastic properties of muscle and connective tissue to increase force
How does bone tissue adapt?
-Mechanical loading helps remodel bones
-Osteoblasts migrate to the bone surface to begin remodeling
-Secrete proteins (mostly collagen) into spaces between bone cells to increase strength
-Collagens forms the bone matrix and eventually mineralizes into calcium phosphate crystals (hydroxyapatite)
-New bone formation occurs primarily on the outer bone surface (periosteum)
-Increase diameter and strength
What effects the rate of bone formation?
-Rate of bone formation varies in axial and appendicular skeleton
-Rate difference caused by different amounts of trabecular (spongy bone) and cortical (compact bone)
-Cortical bone - dense compact outer shell surrounding trabecular board
-Trabecular bone more capable of growth
-New bone formation requires minimal essential strain - the threshold stimulus for new bone formation
-MES level increases as bones become stronger, require progression to continue growth
-Bone remodeling requires six months or longer to occur
-Bone mineral density increases as strength and hypertrophy increase the demands on the bone
Talk about bone remodeling in response to mechanical loading
-Application of longitudinal weight-bearing bends bone
-Osteoblasts lay down additional collagen fibers at bending site
-Dormant osteoblasts migrate to bend site
-Collagen mineralizes - increasing the bone diameter
How do you get a specific area of bone to grow?
-Load the region of the skeleton where bone growth is desired
-Novel forces stimulate bone growth
-Important to load areas commonly affected by osteoporosis
-Osteoporosis is a disease where bone mineral density and bone mass are reduced to critically low levels
-High-impact cyclical loading increases BMD more than low-impact activity
How would you select exercises for osteogenic stimuli?
-Multiple joints
-Direct force vectors through the spine and hip (structural exercises)
-Squat, power clean, deadlift for the lower body
-Shoulder press for upper body
-Progressive overload
-Must place greater than normal demands on musculature to increase bone mass
-Bones respond to higher forces - i.e. 1rm-10rm loads
-Adaptive response reduces stress fractures
-Peak bone mass elevated by bone loading during adolescence and adulthood
-Changing distribution and direction of force vectors in resistance training presents unique stimulus for bone growth within a given region
-If the magnitude and rate of force application is sufficient, bone growth stimulus can be maximized with as few as 30 reps per workout
What is included under the connective tissue umbrella?
Connective tissue includes tendons, ligaments, fascia, and cartilage and forms the critical link between muscle and bone
What is collagen?
-Primary structural component of all connective tissue
-Includes type 1 collagen (bone, tendon, ligaments) and type 2 collagen (cartilage)
-Secreted by fibroblasts - the most common cells in connective tissue
-Enzymes cleave the protective extensions on procollagen molecule following secretion
-Collagen filaments are organized in parallel - pairs of collagen filaments are known as a microfibril
-Microfibrils are arranged into fibers - rely on cross-linking - strong chemical bonds between collagen molecules
What is procollagen?
Parent protein to collagen
What are properties of tendons and ligaments in regards to collagen and bones?
-Primarily consist of tightly packed parallel arrangements of collagen bundles
-Mature tendons and ligaments contain few cells
-Significant strength in bone attachment
-Ligaments contain elastin - allows some stretch to occur during normal joint motion
-Low blood flow means tendons and ligaments are slow to regenerate and slow to recover from injury
What is fascia?
-Fibrous connective tissue surrounding the muscles
-Bundles of collagen arranged in different planes
-Provides resistance from force in multiple directions
-Converges to form tendons at the end of the muscle
What is cartilage?
-Dense connective tissue with high ability to withstand force without damage
-Provides a smooth joint articulating surface - -Hyaline cartilage
-Acts as a shock absorber
-Aids in connective tissue attachments to skeleton
-Fibrous cartilage - tough cartilage found in intervertebral disks and at the tendon-bone junctions
-Receives nutrient supply via diffusion from synovial fluid - Joint immobilization prevents proper diffusion of nutrients - results in the death of healthy cartilage cells
How does connective tissue adapt to resistance training?
Intense anaerobic training can increase the following
-Collagen fibril diameter
-Number of covalent cross-links in the fiber
-Increase in the number of collagen fibrils
-Increase in packing density of collagen fibers
-Collectively increase tendon’s ability to withstand force as well as tendon stiffness - the amount of force required per unit of tendon elongation
How does cartilage adapt to anaerobic training?
-Not fully understood
-Resistance training may prevent thinning or atrophy of cartilage
-Cartilage morphology likely determined by genetic factors
-Moderate-intensity exercise may be adequate for increasing cartilage thickness
-Strenuous exercise does not cause degenerative disease when overloaded appropriately
-Tissue viability can be maintained using a variety of exercise modalities and using a full range of motion
How do tendons and ligaments adapt to anaerobic stimulus?
-Long-term adaptations stimulated through progressive high intensity loading patterns using external resistance
-Low-moderate loads do not change the collagen content of connective tissue
-Forces should be exerted through a full range of motion around the joint
