Principles of Strength Training Slides - Muscle Anatomy & Exercise

Principles of Strength Training PTAS 1116 Muscle Performance 3 Components: 1. Muscle Strength 2. Power 3. Endurance Muscle Strength  Themaximum force that a muscle or muscle group can exert during a contraction  Ability to exert force at any speed Power  Isthe rate of...

Principles of Strength Training PTAS 1116 Muscle Performance 3 Components: 1. Muscle Strength 2. Power 3. Endurance Muscle Strength  Themaximum force that a muscle or muscle group can exert during a contraction  Ability to exert force at any speed Power  Isthe rate of performing muscle contractions over a distance for a specific period of time  Generally associated with high speeds of movement  Required for many functional tasks Endurance  Abilityof the muscle or muscle group to sustain contractions repeatedly or over a a certain period of time Unit 3: Resistance Training-Terminology  Isometric Muscle Action  Static and is produced when mm tension is created without a change in muscle length Unit 3: Resistance Training-Terminology  Isotonic Muscle Action  Dynamic change in mm length.  As mm shortens during activity, it is considered concentric mm action  As mm lengthens during activity, it is an eccentric muscle action Muscle Performance & Resistance Exercise: Definitions and Guiding Principles (cont’d) Overload principle  Description: To improve muscle performance there must be challenge to perform at a greater level  Application of the overload principle  Intensity of resistance exercise  Volume of exercise  Context of the underlying pathology Muscle Performance & ResistanceExercise: Definitions and Guiding Principles (cont’d)  Specificadaptation to imposed demands (SAID) principle  Extension of Wolff’s law  Specificity of training  Transfer of training  Reversibility principle  Detraining Muscle Structure  Composed of thousands of cells called muscle fibers  Each Muscle fiber is covered by the endomysium  Fascicle – Bundles of muscle fibers  Fascicles are covered by the perimysium Muscle Structure  Bundles of fascicles make up the muscle  Covered by the epimysium  Muscle fiber cells do not run the length of the entire muscle  Connective tissue coverings are necessary to transmit contractile forces Muscle Fiber Structure  Made up of threads of proteins called myofibrils  Enclosed in the sarcolemma  Each myofibril contains smaller threads called myofiliments Myofiliments  Protein moleculus  Actin  Thin filiment  Myosin  Thick filiment  You have already learned the sliding filiment theory in A&P I Motor Unit  A motor neuron, its axon and all of the muscle fibers which it innervates  Number of muscle fibers/motor unit varies from 5- 100  Muscles requiring fine degree of control have smaller number of fibers/neuron than large postural muscles Motor Unit Recruitment  Motor units fire in an “all or none fashion”  Multiple Motor Unit Summation  Increasing strength of a contraction is accomplished by increasing the number of activated motor units Motor Unit Recruitment  Contraction strength is also affected by the freq. of stimulation  Wave summation  Fiber stimulated many times in a row with new contraction starting before the previous one ends  Each contraction adds to the force, increasing contraction strength Twitch vs. Tetany  Muscle twitch  Response to a quick stimulation  Quick contraction & relaxation  Tetany  Frequency of contractions/twitches increase, allowing no relaxation between  Muscle contraction the will increase smoothly up to a point of maximum strength Submaximal muscle contraction  Force is obtained by contracting the different motor units a few at a time but in rapid succession so the tension is a tetanic nature rather than a twitching one  Weak contraction  Only 1-2 motor units contract 2-3 times/second  Units take turns contracting so tetany occurs  Strong contraction  Greater number of motor units are recruited and fire more frequently Muscle Force  Cross sectional area (CSA)  The larger the CSA of a muscle, the more tension is produced during a max contraction Adaptations of Muscle  Twochanges occur to muscle due to resistance training 1. Adaptation of the muscle 2. Extent to which the motor unit can activate the muscle Muscle adaptation  1. Hypertrophy of muscle fibers increases the cross sectional area  Caused by increased synthesis of actin and myosin Muscle Adaptation 2. Learned or Neural Changes  Improvement in the ability of the motor unit to activate the muscle after strength training  Untrained individuals can make significant strength gains in just a few days of resistance training through “learning” how to use their muscles Muscle Loss & Immobolization Muscle loss during aging  Adults who do not strength train lose 5-7 lbs of muscle every decade  Onlymuscle training maintains muscle mass and strength during the mid-life years Immobilization  Leadsto atrophy  Can be reversed with resistance training Metabolic Rate  Muscle loss is accompanied by a decrease in metabolic rate  Adults have a 2-5% reduction in metabolic rate every decade  Regular exercise training in adulthood can help decrease loss of metabolic rate  Adding 3 lbs of muscle mass increases metabolic rate by 7% and daily caloric needs by 15% Bone Density  Progressiveresistance training stimulates increases in bone mineral density  Commonly done in programs for osteoarthritis  Exercisesshould involve many muscle groups Glucose Metabolism 4 months of resistance training increased glucose uptake by 23%  Exerciseprograms, including resistance training, are beneficial to decrease DM II onset. Training Principles  Dosage  Increasing the intensity or amount of weight  Changing sets and repetitions  Decreasing rest periods  Changing frequency of exercise  Mode  The method of exercise (use of weights, tubing, etc.) Theraband resistance by color Training Principles  Repetitions  Number of times an exercise is repeated  Makes up one set  Sets  Performance of an exercise for a number of repetitions followed by a rest break or a different exercise  Frequency  How often the exercises are performed  Rest Interval  Generally from 1-3 minutes Overload  Increase in training load that leads to an adaptation in muscle is overload  When an increased training load challenges an individual’s current level of fitness, a response by the body occurs as an adaptation to the stimulus of the training load  Example: increase in muscle strength Overload  Intensity  Effort of training  May be expressed through change in HR, BP, or by the pt. stating how hard the effort is  “Classic” Study: Rutherford and Jones(1986) showed that a ~170% increase in training weights resulted in a ~10% increase in isometric MVC force  Volume  Amount of training Specificity  Nature of the training will determine the training effect  Ex:f you want to run a marathon, just swimming to prepare would not be a good idea Cross training  You may improve performance in one area by training in another mode  Crosstraining benefits are mostly physiological, not performance based Overtraining  Due to training loads that are too demanding on an individual’s ability to adapt  Resulting in fatigue, substitute patterns, and injury Delayed Onset Muscle Soreness (DOMS)  Due to microscopic tearing  NOT LACTIC ACID!!!!!!!  Develops 24-28 hours after exercise and resolves within a week  Eccentric exercise causes more DOMS than concentric  Can be reduced by performing warmup and cool down exercises RESISTIVE EXERCISES INDICATIONS  Muscle weakness or paralysis  Increase bone density  Improve aerobic capacity  Improve pliability and strength of other connective tissue RESISTIVE EXERCISES CONTRAINDICATIONS  Pain  Inflammation  Severecardiopulmonary disease  Loss of joint integrity RESISTIVE EXERCISES PRECAUTIONS  Valsalva  Substitution  Overwork (weakness) /Overtraining (fatigue)  Muscle soreness and acute DOMS  Pathological fracture Next Week More Strengthening Principles & Practices