POE L5 "Resistance Training"

why train?

1. increase muscle strength

2. increase muscle size

3. increase muscle performance/function

define progressive overload

-training that takes place at a higher intensity than the body is accustomed to

how is progressive overload achieved with resistance training?

achieved by gradually increasing the demands on the muscles or increasing training frequency so the muscles are continually challenged and adapt by becoming stronger

define specificity of training

-body adapts specifically to the type of exercise performed, so improvements occur in the muscles, movements, and energy systems that are trained

how can specificity of training be applied to resistance training?

by choosing exercises that target the specific muscles and movements you want to improve, so those muscles adapt and become stronger

define 1-RM

-(one-repetition maximum) is the maximum amount of weight a person can lift for one complete repetition of an exercise with proper form

how much can strength increase with 1-RM?

25-100% increases in strength over a period of 3 to 6 months

define multiple-RM

-(multiple-repetition maximum) is the maximum amount of weight a person can lift for a specific number of repetitions before fatigue

how much can strength increase with multiple-RM?

25-100% increases in strength over a period of 3 to 6 months

what “adapts” in neural adaptations?

1. Increased ability to recruit high threshold (type II) motor units

2. Increased synchronization of motor unit recruitment

3. Decreased inhibition (from Golgi tendon)

4. Increased firing frequency

what is the “time course” of neural adaptations?

• Occur quickly (perhaps after one bout)

• Occur prior to any increase in CSA of muscle

What is specificity of neural adaptations?

• nervous system improves at activating the exact muscles and movement patterns that are trained

define cross-over effect

-train 1 arm/leg and the contralateral also gets stronger

what “adapts” in contractile protein adaptations?

actin and myosin adapt by increasing in number and size, which increases the muscle’s ability to produce force

what is the “time course” of contractile protein adaptations?

6-8 weeks to begin to see measurable increases in CSA

what are the “limits on size” for contractile protein adaptations?

• Most people can see from 5-40% increase in CSA of muscle

• Large genetic component

• Can be affected by drugs (steroids)

What is hypertrophy protein balance?

• positive protein balance

What is atrophy protein balance?

• negative protein balance

what are the acute changes in protein synthesis in response to a single bout of exercise

after resistance exercise, protein synthesis is elevated up to 72 hours, but meal-induced increases last ~24 hours, and protein breakdown also rises to supply amino acids

define hyperplasia

-increase in the number of muscle fibers, rather than their size, contributing to muscle growth

define fiber growth

-increase in the size (cross-sectional area) of individual muscle fibers, mainly due to more contractile proteins, which leads to stronger and larger muscles

cellular pathways

-series of molecular interactions inside a cell that transmit signals and trigger specific responses, such as growth, energy production, or protein synthesis

define mTOR

-(mechanistic/mammalian target of rapamycin) is a key protein kinase in cells that regulates muscle growth by stimulating protein synthesis and inhibiting protein breakdown in response to resistance exercise and nutrients like amino acids.

which hormones increase after resistance exercise, and how do acute changes in these hormones affect muscle hypertrophy?

1. testosterone

2. growth hormone

3. IGF-1 increase

their acute spikes stimulate protein synthesis and signal muscle growth, supporting hypertrophy over time

Define satellite cells

-muscle stem cells located on muscle fibers that activate in response to injury or resistance training, fuse to existing fibers, and donate nuclei, which helps support muscle growth and repair

Define myostatin

-protein that inhibits muscle growth. Higher myostatin levels limit muscle size, while lower levels allow for greater hypertrophy

how do genetics influence muscle hypertrophy?

affects fiber type distribution, hormone levels, satellite cell number, and overall potential for muscle size and strength, setting a ceiling for growth