Principles of Muscular Strength and Endurance

Types of Muscles  Skeletal  Smooth  Lines blood vessels, hollow organs  Cardiac  Found only in the heart

Muscular Strength  Strength: maximal force a muscle can generate for a single maximal effort  1-RM (repetition max) measures muscle strength  If you want stronger, more powerful muscles then your goal should be strength not endurance

Muscular Endurance  Represents the ability of a muscle to generate a sub-maximal force repeatedly over time  If this is your goal then endurance training is what you need

Benefits of Resistive Training  Inc mm strength  Inc mm endurance  Hypertrophy  Inc flex and ROM  Inc lean body mass  Dec body fat  Inc basal metabolism  Inc performance  Maintenance of indep living  Improved phys appearance  Prevention of osteoporosis  Inc CR fitness  Dec BP

Overload  Gradual increase in frequency, duration, and intensity  Goal: recruit or stimulate more muscle tissue  Long-term adaptation: mm hypertrophy  Increase in mm cell size as a result of increased protein synthesis (hyperplasia)  The bigger the mm the more force it can produce

Principle of Specificity  The body will only adapt specifically to the type and nature of exercise training that are encountered  How the body adapts and improves is related to how hard and in what manner it is trained  Speed, contraction type, mm groups

Detraining  Principle of reversibility  MM tissue will not retain any gains if training is discontinued or reduced  Atrophy  Reduction in mm size

Types of Contractions  Isometric  Concentric  Eccentric

Isometric Contraction  No change in mm length (static contraction)  No joint ROM

Concentric Contraction  Dynamic movement in which the mm shortens

Eccentric Contraction  Dynamic movement in which the mm lengthens  Usually occur after the mm has been in a shortened state

Skeletal Muscle Actions  Static Movement: no joint movement  Involve maximal or submaximal mm contraction  EX: Quad sets post ACL surgery  Dynamic Movement: changes in mm length and joint movement  Resistance training

Types of Skeletal Muscle Fibers  Slow twitch (Type I)  Fast twitch (Type II)  Fast-oxidative-glycolytic (Type IIa)  Fast-glycolytic (Type IIb)

Slow Twitch (Type I)  Low intensity, long duration  Aerobic  High endurance and fatigue resistant  Running/cycling rely on Type I fibers  Postural mm are Type I

Fast Twitch (Type IIa and Type IIb)  Rapid forces  Capable of shortening and developing tension 3-5 times faster than slow twitch  Anaerobic, have limited aerobic power  Fatigue rapidly  Type IIa fibers have greater anaerobic capacity than Type I, Type IIb more than Type IIa

Factors Effecting MM Strength and Endurance  Muscle size  Larger the cross section area, the stronger the muscle  Strength training does not increase the strength of contraction, but increases the size of the mm cell  Gender: Females low testosterone level  Age  Use it or lose it  Loss of strength 1%/year after 25 yo

Isometric Training  Increases strength at a given joint angle  No joint movement  Must work a variety of joint angles  Used primarily in rehab  Precautions: hypertension (valsalva effect); indiv presenting coronary risk

Isotonic Training  Most common method of strength training  “Progressive resistive exercise”  Overload principle  Constant resistance  Variable speed of mm contraction  Free weights, machines  Works full ROM

Isokinetic Training  Speed remains constant; weight varies  Used for rehabilitation  Equipment very expensive (Cybex: $45,000)

Determining Amount of Resistance  1 RM  Trial and error  Delorme (10 RM)

1 Repetition Maximum  Determine 1 RM  Take 60% of that value and begin with that amount of resistance  60% will develop strength, but mostly endurance  The closer you work to your 1 RM, the greater the strength gains and the risk of injury

Trial and Error  Determine an amount of resistance you can lift 8 to 12 times

Delorme  10 RM  Complete 3 sets  1 st set: 50% of 10 RM  2 nd set: 75% of 10 RM  3 rd set: 100% of 10 RM

Guidelines for Resistance Training  Warm-up  Adjust equipment  Exercise large muscle groups first  Begin any resistive program slowly and with lower intensities  Overload

Guidelines Cont.  Strengthen your weak side  Work both arms and legs  Isolate muscle groups  Protect the back  Total body workout  2-3 times per week  Alternate days  Alternate equipment

Guidelines Cont.  Maintenance  2 sets, twice/week OR  1 set of 12 reps  Reassess periodically

Free Weights  Use a spotter  Inc chance of injury  Lack of stability  May build strength faster  Wt increments are easily changed

Weight Machines  Weight increments usually 5, 10 lbs  The machine controls line of force  Offers stability  Fewer injuries  No spotter required

What is your goal?  To gain some strength and some endurance?  To build primarily strength?  To build primarily endurance?  To develop great hypertrophy?  As you develop strength, you will develop some endurance and vice versa

Identify your goal  Some strength and some endurance?  8-12 reps (60% of 1 RM)  Primarily strength?  Fewer than 8 reps (80%-90% of 1 RM)  Primarily endurance?  More than reps (60% or less of 1 RM)

Hypertrophy?  50 lbs x 20 reps x 3 sets = 3000 lbs  100 lbs x 6 reps x 3 sets = 1800 lbs Which workout should you use?

Muscle Soreness  Results from structural damage  Desirable to have small, microscopic tears  How to avoid mm soreness:  Stretch, minimize eccentrics, minimize isometrics, use low intensities, progress slowly

Tips  Never hold your breath while exerting force when weight lifting  Valsalva effect or maneuver  Exhale as you apply force  Inhale as you recover

Other Strength Training Techniques  Circuit Training  Plyometrics  Calisthenics

Circuit Training  Uses a series of 12 to 15 stations  Rotate through circuit 3 times  Consists of  Weight training  Calisthenics  Brief aerobic exercise

Plyometrics  Develops mm explosiveness and forcefulness  Consists of an eccentric contraction followed by a concentric contraction  Involves hops, bounds, depth jumping, medicine ball, etc.  High probability of injury

Muscle Dysmorphia  Reverse anorexia  Feeling of being small or weak  Males more common  Supplements/steroid use  Excessive weight training

Anabolic Steroids  Synthetic forms of testosterone  MM hypertrophy  Drug type and amount  Duration of drug usage  Amount of wt training

Female Side Effects  Hypertension  Fluid retention  Decreased breast size  Facial and body hair  Deeper voice

Male Side Effects  Liver dysfunction  Reduced testicular function  Loss of sexual interest  Headaches, nausea, acne  Unpredictable aggressive behavior  Increased risk of coronary heart disease  Increased risk of kidney tumors

Where can I get them?  Easily obtained  Mail order  Illegal channels  Local gyms  Athletes  Physicians  How to mask steroid use? A science of its own

Calisthenics  The body and its extremities provide resistance  Used in aerobic dance routines  EX: crunches and push-ups  Suited to supplement strength training  Good for beginners

Bench Press  1. Lie on a flat bench with eyes directly under the bar.  2. Keep feet flat on the floor with hands spaced evenly slightly wider than shoulder width.  3. Lift bar off the racks and slowly lower the bar to the highest point on chest.  4. Drive the bar upwards and back over the eyes to arms length while exhaling.

Leg Press

Push Ups and Crunches