physiological adaptations to strength training visual bee - visualbee
TRANSCRIPT
Long Term Neuro-muscular Adaptations to resistance training
Work muscle above and beyond what it is accustomed to and it
will adapt !
Overload may be an increase:• Resistance• Repetitions / Sets• Contraction velocity
Overload Principle
Adaptation and Specificity
Muscles adapt differently based on the type of overload placed on
them.
Specify the training regimen to elicit the desired adaptations.
Specificity of Training
4
Training should “overload” the system / muscle type that the individual wishes to train!
• IE: Energy systems, muscle fiber type, and sport specificity.
Muscle Fiber TypesFast Twitch
(FG / Type II)HIGH anaerobic capacity• Type IIa (FOG)
vs. IIb
Fatigue easilyFast contractile velocity (Vmax)
Slow Twitch (SO / Type I)
• Vmax = ½ Vmax of Fast twitch fibers
• High Mitochondria Density
• High no of [Aerobic Enzymes]
Muscle Fiber Types
GeneticsSpecificity of TrainingFiber Conversion* Power = Force X Velocity *
Muscle Fiber Types and Performance
Concentric: Muscle shortens w/ contraction
Eccentric: Muscle lengthens while it is
contracted.
Static (Isometric): No change in muscle
length w/ contraction
Types of Contractions
Isotonic: Movement of a set resistance through a ROM
Isokinetic: Speed of contraction is controlled while subject exerts max effort
Isometric: Training using static contractions
Types of Training
Muscular fatigue is caused by decreases in pH brought about by
buildup of lactic acid.
• LA builds up due to lack of O2 to buffer H+ ions resulting from glycolysis. These H+ combine with pyruvate to form LA.
Fatigue
Glucose
Pyruvic Acid (2)
Energy H+
Lactic Acid (2)
Acetyl Co-A (2)
CO2 & H+
Krebs
CycleCO2
H+
Energy ATP
ATP
Mitochondria
Inter Cellular Fluid
To ETC
Anaerobic
AerobicFatty AcidsAmino Acids
Delayed Onset Muscle Soreness
• Caused by:• Minute tears in muscle tissue*• Acute inflammation*• Alteration in cell’s Calcium regulation*• Osmotic pressure changes (retention of fluid)• Muscle spasms• Any combination of the above
DOMS
Adaptations to Strength Training
Neural Adaptations (First 8-12 weeks)Learn Movement (Motor Learning) Coordination Motor Unit Recruitment Coordination of Motor UnitNeuromuscular inhibition (GTO , Muscle Spindles)
Muscular AdaptationsMuscle Fibers (Physical Changes)
Increase in Size: Hypertrophy (Particularly Type II)• Directly proportional to the VOLUME of overload
• Volume = Resistance X Repetitions
Increase in Number: Hyperplasia (?)
Neural Control• Initial increase in expression of strength due to improved neural control of muscle contraction.
Neural DriveElectromyographic studies indicate lower level in EMG activity to muscular force ratio.
Muscle produced more force with lower amount of EMG activity.
More force with less neural drive.
The increase in maximal neural drive to muscle increases maximal strength.
Muscle enlargement is generally paralleled by increased muscle strength.Increased muscle strength is NOT always paralleled by gains in muscle size.Increase in cross-sectional fiber area of both ST and FT muscle fibers.FT fiber area appears to increase to greater extent than ST fiber area.
Zoe Smith weighs in at 58kg but can clean and press 100kgs
Muscle Hypertrophy
Connective Tissue and BoneSupporting ligaments, tendons and fascia strengthen as muscle strength increases.Connective tissue proliferates around individual muscle fibers, this thickens and strengthens muscle’s connective tissue harness.Bone mineral content increases more slowly, over 6- to 12-month period.
Studies are inconclusive???Most show no change or very littleAppears that IIb IIa w/ intense aerobic trainingLargely genetic and relatively stable (Absolute Number)
Muscle Fiber Conversion?
ATP – CP
• Will increase stores of ATP-CP
Anaerobic Glycolysis
• in levels of glycolytic enzymes• Less LA produced, more efficient
Cori cycle, LA tolerance
Energy System Adaptations
Capillary SupplyIncrease number of capillaries in a muscle helps support metabolism and contributes to total muscle size.
Improved capillarization has been observed with resistance training by body builders but decreased in power and weight lifters.
Increase of capillaries linked to intensity and volume of resistance training.
Time course of changes in capillary density slow (more than 12 weeks).
Strength
Hypertrophy
Neural Adaptations
Training Duration
Pro
gre
ss
8-12 Weeks
Steroids
Steroids
Gains in the Beginning of a Program
Intramuscular Fuel Stores
• [ATP], [CP], and [Glycogen] Increase
VO2max
• Depends on training
Connective Tissue
• Ligament / Tendon Strength Increases
• Increase in connective tissue surrounding muscle fibers Increased bulk
Bone Mineral Density
Other Adaptations
Capillary Density
• Decreases w/ intense, high intensity ST
• No Change w/ circuit or low weight, high repetition ST
Mitochondrial Density
• Decreases due to CSA
Glycolytic Enzymes
• Increase
Other Adaptations
Hormonal Changes
• Acute increase in Epinephrine, Norepinephrine, and Cortisol ( Gluconeogenesis)
Cholesterol
• Total Cholesterol*• HDL-Cholesterol*
* (Results have been somewhat inconclusive)
Other Adaptations
Aerobic Training:
• IIb -> IIa• Hypertrophy of I and IIb fibers• Increase in enzymes,
mitochondria, & capillaries; especially in I (SO) fibers
Specificity of Training
Strength / Power Training:
• Hypertrophy of IIb Fibers
• Increased glycolytic enzymes
• Increased LA tolerance• Increased contraction
velocity?
Specificity of Training
Strength is a function of:Neural FactorsType of fibers engagedAnthropometrics/BiomechanicsSize of Muscle (CSA) *
Strength
Split Routine:• Upper / Lower Body
Alternate Day:• Total body w/ 48 hrs. rest
Antagonist Split Routine:• Agonist / Antagonist
muscle on opposing days.
Frequency Systems
Percentage Circuit Pyramid (Progressive Resistance)
Super Set Maximum Fatigue (Negatives)
Lifting Systems
WARM UP / COOL DOWN ! Start with large muscle / multi-joint exercise and progress to single-joint /
isolation exercises
Overload “Core” muscles last
Recommendations
For the most part,Small decreases in body fatMinimal increases in total body massMinimal increases in FFM, about 0.3 kg/weekly
Body Composition Adaptations
RecommendationsALWAYS allow 48 hours for complete recovery !Start slow !NEVER overload a sore muscle !