Designing Resistance Training Programs
(Pages 181-218) Part 1
What is resistance training?
A systematic program of exercise for the development of the muscular system
What are the health benefits of resistance training?
- Increased muscular strength
- Increased muscular endurance
- Builds bone mass: increase in bone density & bone strength, counteracts loss of
bone mineral, decreases the risk of falls with age
- Increase in size and strength of ligaments and tendons
- Lowers BP in hypertensive individuals
- Increase in fat-free mass
- Decreases fat mass & relative body fat
- May prevent the development of low back syndrome
What are some of the properties that are used to classify muscle fibers?
- Speed of contraction
- Fatigue resistance
- Energy source
How are slow-twitch, intermediate, & fast-twitch muscle fibers different from each
other based upon these properties?
Characteristics Slow-Twitch Intermediate Fibres (TypeFast-Twitch Fibres (Type IIX)
Fibres (Type I) IIA)
Colour Red Red / White White
Contraction Speed Slow Moderately Fast Very Fast
Strength Low Medium High
Fatigue Resistance High Fairly High Low
Source Aerobic Aerobic / Anaerobic Anaerobic
Which protein structures compose individual muscle fibers?
Identify physical activities in which slow-twitch muscle fibers or fast-twitch muscles
- Slow twitch: endurance activities. Ex: jogging
- Fast twitch: strength and power. Ex: sprinting
How does resistance training increase muscle strength?
- Hypertrophy of the muscle fibers - Muscle learning
What do hypertrophy, hyperplasia, and muscle learning mean?
- Hypertrophy: an increase in the size of a cell or tissue larger muscle fibers
- Hyperplasia: increase in number of muscle fibers
- Muscle learning: body’s ability to recruit motor units increases strength even
before muscle size increases
How does resistance training hypertrophy skeletal muscle?
- First 2-8 weeks: rapid increase in strength due to neural adaptations. No
difference in rate of progression between males and females
- 8-10 weeks: muscle hypertrophy contributes more than neural adaptation to
strength gains, but hypertrophy eventually levels off. Greater hypertrophy in
males due to testosterone
- Greater than 6 months: contributes to increase strength without hypertrophy.
Believed that a secondary phase of neural adaptation is most likely responsible
for strength gains occurring between 6-12 months of training. Hypertrophy may
be limited to no more than 12 months
Does resistance training preferentially increase the size of one fiber type over
Preferentially increases the size of fast-twitch muscle fibers most responsive to a
Does resistance training increase the number of muscle fibers?
What is a motor unit?
- Makes up the functional unit of movement
- Made up of a nerve cell called an alpha motor neuron connected to a number of
- To exert force: the body recruits one or more motor units to contract.