Muscle in the Body And MORE! - docmartin.org Strength, Hypertrophy And MORE! Len Kravitz, Ph.D. University of New Mexico [email protected] Note, several graphics are …

Muscle, Strength, Hypertrophy And MORE!

Len Kravitz, Ph.D.University of New [email protected]

Note, several graphics are not included due to copy rightIssues.Thanks so much.

Muscle in the Body Smooth: involuntary

Cardiac: involuntary

Skeletal: voluntary

430 muscles in 215 pairsChemical composition

75% water; 20% protein; 5% other

Fascicle or Fasciculus

Sarcolemma

Perimysium

Endomysium

Muscle fiber = muscle cell

Up to 1000 nuclei

Do not extend the entire length of a muscle

Sarcolemma: “polarized plasma membrane”

Sarcoplasm

Glycogen & myoglobin

Muscle Fiber

SarcomereSmallest contractile unit of muscle:

Myosin:Type IType IIaType IIb/x

Actin

SarcomereActin

Myosin Z lineM-line

H zone

A Band

I band

TitinDesmin

M creatine kinase

C protein

Actin & Myosin ProteinsWhere are the binding sites?

Sliding Filament Theory

Z line Z line

H zoneI band

A Band

Energy for Muscle Action

HydrolysisATPase

New Research on Lactate!

Lactate is associated with burn (acidosis)!It is the H+ that create the acidic environment

Where dothe H+ comefrom?

Robergs, R.A., Ghiasvand, F., Parker, D. (2004). Biochemsitry of exercise-inducedmetabolic acidosis. Am J Physiol Regul Integr Comp Physiol. 287: R502-R516.

Acidosis and Buffering (Neutralizing)

H+

H+

H+

H+

H+H+

H+

H+ H+acidosis

ATP

PhosphagenEnergy System

Glycolysis

NADH+H+

NADH+H+

NADH+H+

NADH+H+NADH+H+

Lactate

ATP

Neuromuscular FatigueAcetylcholine

Acetylcholine may be reducedCholinesterase may become hyperactiveCholinesterase may become hypoactiveAnother substance may compete with acetylcholineCalcium may accumulate within T-tubules

Gardiner, P. 2001. Neuromuscular Aspects of Physical Activity. Human Kinetics

Muscular Fatigue

H+ interfere with Ca2+

acidosis slows ATPase

Gardiner, P. 2001. Neuromuscular Aspects of Physical Activity. Human Kinetics

Distribution of Fiber Types Person’s arm and leg muscles have similar fiber types

Exception is soleus: almost completely ST ineveryone

Can you change your fiber type?

Type I Type IIa

Vigorous resistance trainingPlus interval aerobic training

2 to 10x faster

What About Hypertrophy?

How much can fibers grow?20% to 70%

Most studies: 20% to 45%

Gardiner, P. 2001. Neuromuscular Aspects of Physical Activity. Human Kinetics

How much bigger can fasttwitch get compared to slowtwitch in absolute size?

2x as large

Neural Drive

Motor unitsfiring

SynergisticMuscles

FiringSync

Early Strength Gains Why are some people always ‘firmor tone’ while others are not?

Called muscle bias

30% of myosin alternatively binding at rest

Hypertrophic Factors of Resistance Training

in size of actin and myosin proteins in number of actin and myosin proteins in sarcoplasm in size of connective tissue

No change in number of muscle fibers No longitudinal splitting (hyperplasia)

What Happens as Muscle Ages?

Type grouping

What Happens to Muscle as youGain Flexibility?

Add Sarcomeres What Happens to Muscle as youLose Flexibility?

Lose Sarcomeres

The Major RMR Controversy!

Protein turnover (12-25% ATP consumption)Enzyme reactionsMetabolic hormonesReplenishment of glycogen storesNa+/K+ ATPase (20% ATP consumption)Ca2+ ATPase (4-6%)Heat productionATP production efficiency (proton leaks)

Schrauwen, P. & Hesselink, M. (2002). UCP2 and UCP3 in muscle controllingbody metabolism. Journal of Experimental Biology, 205, 2275-2285.

UCP2 and UCP3 in MuscleControlling Body Metabolism

Schrauwen, P. & Hesselink, M. (2002). UCP2 and UCP3 in muscle controllingbody metabolism. Journal of Experimental Biology, 205, 2275-2285.

Periodization Model (Kravitz)

Fleck & Kraemer. The Ultimate Training System, 1996.

Type I, IIa

Transition

Type IIa Type IIbx Type I