Chapter 6: resistance training pt 1 (ther ex)

• Muscle performance


  The capacity of a muscle to do work (force X distance)
• Muscle performance


  • Influenced by all body/organ systems
  • In order to carry out the physical demands of life safely and efficiently, muscles must be able to produce, sustain, and regulate muscle tension to meet demands
• 3 elements of muscle performance


  • Strength
  • Power
  • Endurance
• Resistance exercise


  Any form of active exercise in which dynamic or static muscle contraction is resisted by an outside force applied manually or mechanically
• Resistance exercise


  • Essential element for rehab and integral for conditioning programs to promote and maintain health and well-being
  • Focus of the chapter is manual resistance to the extremities as there are spinal and joint specific chapters later in the text
• Muscle Strength


  The ability of contractile tissue to produce tension and a resultant force based on the demands placed on the muscle
• Greatest measurable force


  The greatest measurable force that can be exerted by a muscle or group to overcome resistance during a SINGLE maximum effort (1 Rep Max/1RM)
• Functional Strength


  The ability of the neuromuscular to produce, reduce, or control forces, contemplated or imposed, during functional activities, in a smooth, coordinated manner
• Strength Training


  A systematic procedure of a muscle or muscle group lifting, lowering, or controlling heavy loads (Resistance) for a relatively low number of reps or over a short period of time
• Increases in muscle strength


  • Primarily due to neural adaptations (first 4 weeks)
  • Increase in muscle fiber size
• Muscle Power


  • Related to strength and speed of movement
  • Defined as the work (force x distance) produced by a muscle per unit of time (force x distance/time)
  • Can be expressed by either a single burst of high intensity activity (anaerobic power) or repeated bursts of less intensity (aerobic power)
• Power Training


  • Exercise that emphasizes strength AND Speed of movement
  • Muscle strength is necessary for developing muscle power; usually started after pt can do two sets safely and correctly
  • Increase the work a muscle must do or reduce the time a muscle has to produce a force will enhance power
• When completing power training with a patient, it is done in short bouts, so the anaerobic and phosphagen systems are stressed
• Muscle Endurance


  The ability to perform low intensity, repetitive, or sustained activities over a prolonged period of time
• Cardiopulmonary endurance


  Total body endurance associated with repetitive, dynamic motor activities and involve the use of large muscles of the body (walking)
• Muscle endurance


  Local endurance/aerobic power: the ability of a muscle to contract repeatedly against a load/resistance, generate and sustain tension, and resist fatigue over a period of time (postural muscles)
• Muscle endurance training causes adaptive changes in Type I muscle fibers
• Muscle strength and endurance are NOT interchangeable terms
• Endurance training


  Having a muscle contract or lift or lower a light load for many reps or sustain a muscle contraction for an extended period of time
• Key parameters of endurance training


  • Low intensity muscle contractions
  • Large number of reps
  • Prolonged period of time
• Results of endurance training


  • Increased oxidative capacity and metabolic capacity of the muscle
  • Decreased force on joints, less irritation to soft tissues, and overall comfort
• Overload Principle


  • The foundation of resistance exercise
  • A load that exceeds the metabolic capacity of a muscle; challenge the muscle to perform at a level greater than that to which it is accustomed
• Progressive loading


  Manipulating the intensity (resistance) or volume (number of reps/sets/frequency) of exercise
• In strength training, resistance is emphasized; with endurance training, emphasis is on time or number of reps
• Performing seated LAQs with a 2# cuff weight when the quads need to lift up to 40% of body weight to perform a sit→ stand transfer independently is not an appropriate overload
• Specific Adaptation to Imposed Demands (SAID) Principle


  • Extension of Wolff's law - body systems adapt over time to the stresses placed on them
  • Specificity of training: exercises incorporated in a program should mimic the anticipated function; mimic mode, velocity, limb position, and movement pattern of exercise as well
• The muscle working at the ankle from heel strike to foot flat is the tibialis anterior, and it is working eccentrically
• Transfer of training/Overflow/Cross-training effect

  • Carryover training effects from one variation of exercise or task to another
  • Have been reported to occur on a limited basis with respect to velocity, and mode of exercise
  • Can also occur from an exercised limb to a non-exercised, contralateral limb in a resistance training program (cross training)
  • Muscle strength program has been shown to improve muscular endurance in a moderate way, but endurance training had little to no effect on cross training to gain strength
  • Some improvement in strength at velocities higher or lower than training speed
• Exercise programs must still be created based on individual goals and to replicate desired functional activity
• Reversibility Principle


  • Detraining: reduction in muscle performance; begins within 1-2 weeks after cessation of resistance exercises and continues until training effects are lost
  • Maintenance programs are important (same resistance, decreased frequency)
  • Incorporate gains in strength and endurance into daily activities
• The #1 goal for resistance exercise is always safety
• Valsalva Maneuver


  • Expiratory effort against a closed glottis with contraction of the abs
  • Increased intra-abdominal and intra-thoracic pressures, which forces blood from the heart and temporarily increases arterial blood pressure
  • Occurs during high effort isometric and dynamic muscle contractions, but rise in BP appears to be the same at all velocities of movement despite decreasing force output of muscle
  • Rise in BP appears to be based more on extent of effort, not just on type of muscle contraction
• Patients at risk for resistance exercise include those with a history of CAD, MI, cerebrovascular disorders, HTN, those who have undergone neurosurgery, eye surgery, or intervertebral disk pathology
• Resistance training for at-risk patients


  Start with low resistance training (30-40% 1 RM for UE and 50-60% 1RM for LEs)
• Prevention is key during resistance exercise - do not let the patient hold their breath
• Patients should be asked to breathe rhythmically, talk, or count during exercise
• Patients should breathe out during the hardest part of the exercise
• Avoid high intensity exercise for at-risk patients
• Substitute Motions


  • Usually occurs when resistance is too high
  • Prevent by choosing correct resistance and giving adequate stabilization
• Overtraining


  • Decline in physical performance in healthy individuals participating in high intensity, high volume strength and endurance training
  • Brought on by inadequate rest, too rapid progression of exercise, or inadequate diet and fluid intake
  • Individual fatigues more quickly and requires more time to recover from exercise