Lab 3: Resistance Training and Torque

If we are training for power what do we want to avoid?

• Don’t want to get fatigued!

• Avoid higher reps

• Used highest amount of force possible (but still want individual to move relatively quickly)

What adaptations are seen in the neural system with strength training?

• Increases in supraspinal activation (from brain)

  • Better able to elicit more motor units (up-regulation of synapses)

• Reduced co-activation of antagonist (release of DOF)

  • Strength gains are improved if you reduce co-activation

• Greater activation of the agonist and synergist muscles (EMG)

  • More output will create more activation

• Increased motor unit synchronization

  • Increase amount of strength with more coordination

What adaptations are seen in tendons and ligaments with strength training?

• Tendons decrease compliance (become stiffer)

• May increase CSA (over long-term exercise)

What happens to tendon/ligaments with aging? Can strength training reverse these effects?

• As we age, tendons/ligaments increase compliance (less able to transmit forces)

  • Older tendon has more collagen but less water and elastin (so increases rigidity and makes it more prone to injury)

• Strength training in older individuals can decrease compliance to level of young tendon

What adaptations are seen in bone with strength training?

• Increase in bone mineral density

• Increase in bone mass

How does hypertrophy occur?

• Occurs through sarcomerogenesis (in parallel)

  • Due to altered gene expression

• DOES NOT occur through hyperplasia

What is sarcomerogenesis?

Refers to the ability of the muscle fiber’s genetic machinery to change either the quantity (number of proteins leading to more sarcomeres) or quality (specific fiber types) of protein it expresses

DNA → RNA → Protein

Time between sets needs to ________ to train for hypertrophy.

(Hint, think of a body builder)

Time between sets needs to increase to train for hypertrophy

What is the difference between strength training and hypertrophy training?

Not much difference besides for hypertrophy training there is an increased time between sets (like 5-10 minutes between sets)

What mitochondrial adaptation occurs with muscular endurance training?

• Muscular endurance training will lead to a decrease in fatiguability

• Increase in mitochondria and capillaries in Type I fibers (primarily

What mitochondrial adaptation occurs with strength training?

Changes in mitochondria density and fiber type transition will occur prior to muscle getting larger

Using the ACSM guidelines to improve performance, what is the % of 1RM that should be used for those who are untrained, recreational, or a serious athlete?

• Untrained: 45-60% 1RM

• Recreational: 60-80% 1RM

• Serious Athlete: 80-95(100)% 1RM

“Untrained” or “Painful” populations gain strength with _____ loads and ____ reps

“Untrained” or “Painful” populations gain strength with lighter loads and higher reps

(really becomes like endurance training)

What are the repetitions, sets, and frequency (times/week) of a resistance training program that emphasizes strength gains?

• Moderate Load

• 8-12 reps

• 2-3 sets

• 2-4 days / week

What are the repetitions, sets, and frequency (times/week) of a resistance training program that emphasizes endurance gains?

• Low load

• 15-30 reps

• 2-3 sets

• 2-6 days / week

What are the muscular strength training parameters (% 1RM, reps, sets, and frequency) for an untrained individual?

• 45-60% 1RM

• 15-20 reps

• 1-3 sets

• 2-4 days / week

What are the muscular strength training parameters (% 1RM, reps, sets, and frequency) for a recreational lifter?

• 60-80% 1RM

• 8-12 reps

• 2-4 sets

• 2 days / week (for each muscle group)

What are the muscular strength training parameters (% 1RM, reps, sets, and frequency) for an athlete or serious lifter?

• 80-100% 1RM

• 5-6 reps

• 4 sets

• 2 days / week (for each muscle group)

What are the muscular endurance training parameters (% 1RM, reps, sets, and frequency)?

• Same as the “untrained individuals” that are gaining strength

• 40-60% 1 RM

• 15-30 reps

• 1 -3 sets

• 2-4 days / week

What are some signs and symptoms of fatigue?

• Uncomfortable sensation in the muscle (pain)

• Trembling of the muscle

• Unintentional slowing of muscle contraction on successive reps

• Jerky movements

• Inability to move through full ROM

• Substitution patterns

• Inability to continue low-intensity physical activity

• Decrease in peak torque (isokinetic)

What type of training would be considered high reps and low load? What phase of healing would we use this type of training in?

• Muscular Endurance Training

• Fibroblastic Phase

What type of training would be considered low reps and high load? What phase of healing would we use this type of training in?

• Muscular Strength Training

• Maturation Phase

What type of training would be considered low reps and low load? What phase of healing would we use this type of training in?

• Muscular Endurance Training

• Inflammatory Phase (may also need to consider more limited ROM)

How do we make an exercise more challenging?

• Move weight farther from joint axis (increasing moment arm)

• Increasing the weight / load

We cannot change ________ torque but we can change ________ torque

We cannot change internal torque but we can change external torque

What are three types of internal forces in the body? What kind of forces do they create?

• Muscle - creates movement or resists movement

• Ligaments - applies opposing forces during distraction/shearing forces

• Bone - long bones apply compressive forces on each other

Define an external force. What are some examples?

An external force is any force that is not coming from inside the body (e.g., gravity, friction, external load)

T/F: External forces only restrict movement

False!

External forces can facilitate or restrict movement

What is torque?

• Rotation around an axis

• Torque = Force x MA

• MA is the moment arm = perpendicular distance from the axis of rotation

Consider the equation: Torque = MA x Force

If the MA is doubled then the force can be ______.

If the MA is doubled then the force can be halved

Where is the axis when using a resistance band?

Axis is in the hand

T/F: The internal moment arm changes throughout ROM

True

If a joint system needs to be able to develop large torques, what three options could be used?

• High Force

• Large MA

• Combine muscles

Muscle force varies with changes in __________.

Muscle force varies with changes in joint position

Joint reaction force (JRF) is greater with…

A shortened external moment arm

T/F: To gain muscular strength, we want to overload throughout ROM

True