Strength Training Principles

Resistance Training

• Increase load to improve strength; decrease load to improve endurance.
• Strength training for novice-intermediate lifters involves using 60-70% of their 1RM (one-repetition maximum), while advanced lifters should use 80-100% of their 1RM.
• Strength training volume: 1-3 sets of 8-12 reps for novice-intermediate; 2-6 sets of 1-8 reps for advanced.
• Novices should train the entire body 2-3 days per week.
• Intermediates should train 3 days with total body workouts or 4 days using upper/lower body splits, training each major muscle group twice a week.
• Advanced lifters should train 4-6 days per week training each major muscle group 1-2 times per week.
• Elite athletes may train 4-7 days per week, depending on the training cycle phase, maximizing muscle group stimulation.
• Higher training frequency generally leads to greater strength gains.
• Exercise selection depends on patient goals, specificity, and transference.
• Strength training should incorporate concentric, eccentric, and isometric muscle actions depending on goals.
• Emphasize multi-joint exercises for maximizing overall muscle strength.
• Rest intervals for endurance are around 30 seconds, while strength training requires up to 3 minutes.
• Strength training = 2-3 min rest for high intensity/heavy loads; 1-2 min for lower intensity/lighter loads.
• Perform multi-joint exercises before single-joint exercises.
• Prioritize power movements first.
• Work large muscle groups before small muscle groups.
• Rotate agonist-antagonist muscle pairings.
• For hypertrophy, target weak muscles first.
• Exercises requiring higher skill/coordination should be performed first.

Power/Plyometrics

• Use low to moderate loads.
• Upper body: 30-60% of 1RM; Lower body: 0-60% of 1RM, low RPE (rate of perceived exertion) and high RIR (reps in reserve)
• Frequency: 2x/week.
• Time: 1-3 sets of 3-6 reps for trained individuals, or 6-10 reps for untrained individuals/older adults.
• Rest for more than 2 minutes between sets.
• Emphasize maximal velocity during movement.
• Increase stability to enhance power output.

Stretching

• Types: manual, mechanical, self-stretching, passive, active, assisted.
• Use low intensity with low load.
• Utilize slow speeds/velocities for muscle relaxation, safety, and ease.
• Static stretches should be held for 30-60 seconds, accumulating 5 minutes per muscle per week.
• Frequency: 5 days/week for static stretching.
• Stretch in the direction opposite of the muscle's action.
• Lengthen single-joint muscles across the single joint they cross and multi-joint muscles across all joints they cross.

Intensity Management

• Understand how to manage light, moderate, and vigorous intensity levels based on patient scenarios.

Indications, Contraindications, and Precautions

Resistance Training

• Indications: desire to improve the rate of force development.
• Contraindications: inflammation, pain, severe cardiopulmonary disease.
• Precautions: ensure proper technique and form, correct compensatory movements, progress patients with bone density pathologies carefully, warm-up with active, dynamic exercises, select appropriate starting and progression loads, allow 48-72 hours between sessions, ensure appropriate temperature, monitor vitals and tolerance, stop if technique or speed regress.

Plyometric Training

• Indications: enhancing rate of force production, established strength base.
• Contraindications: inflammation, pain, significant joint instability.
• Precautions: intolerance to high stress, shock absorbing activities; select beginning-level drills for older adults and kids; ensure 95% normal flexibility and 85% normal strength before initiating; warm-up with active, dynamic exercises; emphasize safe landing techniques; progress repetitions before resistance or jump height/length; allow 48-72 hours between sessions; stop if patient can no longer perform activity with good form because of fatigue; monitor for fall risk.

Stretching

• Indications: limited ROM due to scar tissue, adhesions, or contractures; restricted motion leading to preventable structural deformities; weakness of opposing tissue limiting ROM; prevention or reduction of injury risk; warm-up/cool-down; perception of tightness improving with stretching.
• Contraindications: bony block, recent fracture, acute inflammation or infection, acute pain with muscle lengthening, hematoma, hypermobility with instability, sharp pain on elongation, disruption of healing process, when stiffness enables function in paralyzed patients.
• Precautions: osteoporosis, post-immobilization, elderly, edema, monitor for post-stretch soreness and overstretching.

Exercise Sessions and Programs

Periodization

• Classical: high volume, low intensity to low volume, high intensity.
• Reverse: low volume, high intensity to high volume, low intensity.
• Undulating: frequent volume and intensity changes throughout the cycle.

Sets, Reps, Rest

• Repetitions: number of times a movement is repeated.
• Sets: predetermined number of consecutive repetitions.
• Rest: replenish energy stores (ATP & phosphocreatine), remove metabolic byproducts, optimize training volume and intensity.
• Endurance-focused training requires shorter rest times.
• Power training requires lots of rest.
• Strength: high load, low reps, longer rest.
• Local Muscular Endurance: low intensity, high reps, longer set duration.
• Power: low to moderate load, high velocity.
• Hypertrophy: moderate to high load, middle rep range, higher volume.

General Physiology

Receptors Involved in Stretching

• Golgi Tendon Organs (GTO): monitor changes in tension, contribute to reflexive muscle relaxation during stretching through autogenic inhibition.
• Muscle Spindles: sensitive to quick and sustained stretches, activate reciprocal inhibition.
• PNF (Proprioceptive Neuromuscular Facilitation) uses autogenic and reciprocal inhibition.

Muscle Fiber Recruitment

• Isometric: Type I → Type IIa/IIx; recruitment increases with intensity/duration.
• Concentric: Type I → IIa → IIx; follows size principle; high velocity = more IIx.
• Eccentric: Type II (especially IIa, IIx); fewer units needed, but more force per unit.

General Adaptations to Exercise

Plyometrics & Power

• Greater eccentric contraction leads to greater force production in concentric contraction.
• Increase in muscle fiber diameter (hypertrophy), fiber length, pennation angle.
• Shift in muscle fiber type from type IIX to type IIA.
• Increase in tendon stiffness; amount of force transmitted laterally from muscle fiber to surrounding collagen tissue; capillaries.
• Improves coordination, excitability of neuromuscular receptors, reactivity of neuromuscular system.
• Reduces fatigue and edema.

Stretching: Physiology & Interventions

Contracture Types

• Myostatic: musculotendinous unit has shortened, no muscle pathology present (e.g., gastrocnemius/soleus from high heels, poor posture).
• Pseudomyostatic: result of hypertonicity associated with CNS lesions.
• Arthrogenic/Periarticular: intra-articular pathology (effusion, osteophytes) impairs movement.
• Fibrotic: changes in connective tissue of muscle/periarticular fibers create adhesions between tissues (scar tissue).

Immobility Effects

• Leads to muscle atrophy and weakness.
• Increase in fibrous and fatty tissue within muscle.
• Decrease in overall extensibility.
• Decrease in amount of contractile protein, muscle fiber diameter, number of myofibrils, intramuscular capillary density.

Hypomobility and Instability

• Hypomobility: decreased mobility or restricted motion at a single joint or series of joints. Soft tissue can become shortened including contractile and noncontractile elements (tendons, ligs, joint capsule, fascia, skin, muscle)
• Instability: hypermobility in the absence of dynamic stability; lack of control and unstable joints even without full ROM.

Creep

• Time-dependent property of tissues; low load range allows tissue to relax into position, enhancing the stretch.
• Heating the tissue enhances creep due to increased blood flow and decreased viscosity.

Connective Tissue Composition

• Collagen fibers: provide strength & stiffness.
• Elastin fibers: extensibility; more elastin = more flexibility.
• Reticulin fibers: provide tissue bulk.
• Ground substance: gel made of proteoglycans & glycoproteins; hydrates matrix, stabilizes, resists compressive forces.

Hip and Knee Positioning for Stretching

• Extending the hip and flexing the knee stretches the rectus femoris and TFL.
• Adding 5-10 degrees of abduction puts the TFL on slack, isolating the rectus femoris more.
• To emphasize the TFL more, put it into some adduction.
• Hip flexion and knee extension - stretch hamstrings.
• Medial hamstrings - lateral rotation of hip + minimize abduction.
• Lateral hamstrings - medial rotation at hip + minimize adduction.

Rotation

• 90 degrees external rotation prone going to available internal rotation involves eccentric external rotation until neutral then concentric internal rotation until meets rom

Unit 3-4 Quiz Answers

• What best defines local muscle endurance? Capacity of the muscles to sustain repeated contractions against an external load and resist fatigue
• What is an example of a power exercise? A vertical jump
• Which of the following best defines power in an exercise context? The ability to exert force quickly or the rate at which work is done
• In humans, what is the proposed mechanism of muscle growth? Increased muscle cell size
• Which muscular adaptation can occur most quickly in response to exercise? Increased neural input (rate coding, total recruitment)
• What type of exercise is best for improving overall muscle strength? Compound exercises that engage multiple muscle groups
• Increased rate of force development is the goal of which training method? Power
• At what stage of training should plyometric exercises typically be introduced? After a foundation of strength has been developed