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 !