1.Chapter 4: Strength Training Email: mwittbrodt3@gatech.edu Reminder: Part I Ex. Program Due Fri Feb 21 **Office Hours: Tue 11:30 1:00**

2. Learning Objectives Explain the benefits of developing muscular strength and endurance Describe how muscles contract Distinguish between the muscle fiber types Classify the types of muscular contractions Identify the changes that occur in response to strength training List the factors that determine muscle strength and endurance Outline the principles used in designing a strength and endurance program Distinguish between the types of training programs Design a program for improving strength and endurance 3. Strength Training in Daily Living Reduces joint and/or muscle injuries Reduces low back pain and age-related decreases in strength Helps prevent osteoporosis Increases resting energy expenditure 4. Muscle Structure and Function Primary function: provide force for movement, maintain posture, and regulate temperature As they shorten or lengthen, movement occurs Motor Unit: Motor nerves and the muscles it innervates 5. Types of Muscle Contractions Important Prefixes/Terminology for Muscle Contraction: -Iso = same -Metric = movement -Kinetic = velocity -Tonic = tensionIsotonic -Same tension -Most exercises and sportsIsokinetic -Same velocityIsometric -no movement - Useful in rehab 6. Major Muscles of the BodyQuadriceps 7. Positive Work Shortening against gravityNegative Work Lengthening against gravity 8. Agonist vs. Antagonist & Muscle Balance Agonist: Muscle which causes movement stemming from contraction Antagonist: Acts opposite of agonist 9. APPLYING MUSCLE STRUCTURE AND FUNCTION TO RESISTANCE TRAINING AND EXERCISE PERFORMANCE 10. Muscle Fiber Types Fiber TypeForce GenerationFatigueSlow (Type I)Slow and minimalVery ResistantFast (Type IIb)Fast and GreatVery LittleIntermediate (Type IIa)Fast and GreatResistant- Mostly genetically determined - What are differences in elite endurance runners vs. elite sprinters?- Some transient fiber type conversion with specific training 11. Fiber Recruitment Recruitment Principle 1: More muscle fibers = increased muscle forceRecruitment Principle 2: Slower muscles recruited before faster muscles 12. Adaptations to Strength Training Hypertrophy Increase in muscle fiber size Hyperplasia Increase in muscle fiber number - Very minimal; does not contribute to adaptations Muscle Fiber Recruitment Steroid UseStrengthHypertrophy Increase in muscle innervation Time 13. Endurance Training and Muscle Changes Trappe et al. 2006 J Appl PhysiolFiber TypePre-Training %Post-Training %Type I48%57%Type IIa30%30%Hybrids22%13%Take Home: -With 16wk endurance training, there was an INCREASE in TYPE I fibers, a DECREASE in Hybrids, and NO CHANGE in Type IIa. -The Type I fibers also DECREASED in SIZE but INCREASED in FORCEMuscles change with any type of training 14. Rate of Improvement -Depends on initial strength level -Rapid strength gains in relatively untrained beginners -More gradual gains in trained people with high levels of strengthGender Differences-Little difference in initial responses to strength training -After long-term training, men show greater gains due to higher testosterone levels-Women DO NOT exhibit bulky muscles 15. Safety Concerns Use spotters Don't drop weights Always warm up Breathe during exercises Use slow movements Start with light weights and work up gradually 16. Chapter 5FLEXIBILITY 17. Learning Objectives Discuss the value of flexibility Identify the structural and physiological limits to flexibility Describe the three categories of stretching techniques Design a flexibility exercise program 18. Benefits of Flexibility -Increased joint mobility -More efficient body movement -Better posture -Prevents lower back pain -hypokinetic disease 19. Structural Limitations of Movement 1. The shape of the bones 2. Stiffness of the muscle 3. The connective tissue within the joint capsule 4. Tendons (connect muscle to bone) 5. Tight skin 20. Benefits of Good Posture Minimize: - Joint Wear and arthritis - Spine Alignment Stress -Spine nerve stress -Muscle fatigue and pain -Overuse problems and strains Contributes to good appearance 21. Evaluating Flexibility Flexibility is joint specific Sit and Reach Test: -Measures ability to flex the trunk -Focuses on lower back muscles & hamstringsShoulder Flexibility Test -Measures range of motion at the shoulder 22. Improving Flexibility Dynamic Stretching Goal is to prepare body to exercise Conducted prior to exercise and highly recommended Fluid, controlled motion of joint through full ROM Increases blood flow to muscles/joints Increases neuromuscular activity between CNS and PNS Ballistic Stretching Rapid, forceful, bouncing movements More likely to cause injury and thus not recommended Static Stretching Goal is to increase flexibility and recover from exercise Most effective method to increase flexibility at end of exercise, not prior to exercise Slow lengthening of muscles, held for fixed periods 23. Proprioceptive Neuromuscular Facilitation (PNF) Series of motions combining stretching with contraction and relaxation of muscles -relies on contract-relax (CR) and contract-relax/antagonist contract (CRAC) stretching**PNF and Static stretching should not be completed BEFORE a muscular strength or muscular endurance exercise session** 24. Applying the FITT Principle to a Flexibility Exercise Prescription Prescription will vary depending on initial flexibility level Exercises should be static or PNF stretches Recommended sample program might include the following Starter Phase Frequency: 1 session Intensity: 5-minute session/hold for 15 seconds/mild discomfort Time/duration: 1 week Slow Progression phase Frequency: 25 sessions per week/add one session per week Intensity: 1030-minute sessions/hold for 2030 seconds (add 5 seconds per week)/mild discomfort Time/duration: 612 weeks Maintenance Phase Frequency: 45 sessions per week Intensity: 30-minute sessions/hold stretches up to 30 seconds Time/duration: start after about week 7 depending on progress 25. Avoid Stretching Injuries 26. Sample Exercise Prescription for Flexibility: Beginner 27. Sample Exercise Prescription for Flexibility: Intermediate 28. Sample Exercise Prescription for Flexibility: Advanced 29. Maintaining Flexibility Make a commitment to regular stretching Use time management Set aside time for 35 sessions per week Stick to your schedule Build in stretches during everyday activities Make it fun: listen to music, watch TV while stretching 30. Exercise Myth #1: Barre Workout Question: Will a concentrated effort towards small movements actually make a difference?Experience a class 31. Overload and Specificity Applied to Strength Training1)Resistance 2)Sets x Repetitions 32. Muscle Architecture Convergent (Fan Shaped) Muscle: Attachment is wider than point of insertion (i.e. Pectoralis Major) Pennate Muscle: Muscle has diagonal fibers in relation to tendon (i.e. rectus femoris) Parallel Muscle: Muscle fibers run parallel to each other (i.e. Biceps) 33. Muscle Architecture 90 degree angle 30 degree angleMost overall activity of pectoralis muscleMost overall activity of upper part of pectoralis muscle140 degree angleMost overall activity of lower part of pectoralis muscle