PT 856 lecture 3: resistance training

Resistance training details

- Effective intervention strategy to enhance muscular performance via muscular and neural adaptations

Basic elements of muscle performance (3)

- Strength

- Power

- Endurance

Muscle strength (muscle vs neural adaptations)

- Muscle: increased cross-sectional area or hypertrophy, selective hypertrophy of fast twitch type 2

- Neural: increased recruitment and rate-coding

What motor units are recruited first (hennemans size principle)

- Small motor units then large

Spatial vs temporal summation

- Spatial: increase in force by increasing the number of motor units recruited

- Temporal: increased in force by increasing the firing rate

Increases in muscle strength are driven by what in the first 8 weeks.

- Neural adaptations

Muscular adaptations to lead to increased endurance

- Increased capillarization

- Increased mitochondrial density

- Increased oxidative capacity

What is most effective in eliciting tendon adaptations

- High intensity loading

What do ligaments adapt to?

- Mechanical stress

o Less than tendons

Force velocity curve details (eccentric vs concentric)

- Eccentric:

o Slower: decreased force

o Faster: increased force

- Concentric

o Slower: increased force

o Faster: decreased force

Force- length relationship

- Optimal length is in midrange -> more overlap and more force generated

Three energy system

- ATP-PCR

- Anaerobic glycolysis

- Oxidative

When are the three energy systems used?

- ATP-PCR: rapid max effort (second)

- Anaerobic glycolysis: brief moderate- high intensity (minutes)

- Oxidative: endurance (multiple mins - hours)

What is a one rep max

- Maximal weight an individual can lift for only one rep

What is the gold standard for assessing strength

- Isokinetic dynamometer

An isokinetic dynameter can test what types of contractions

- Isokinetic: resistance against an angular velocity

- Isometric: resistance against fixed surface

Power measures

- Chair rise test

- Vertical jump

- Single arm shotput

- Wingate test

Endurance measures

- 6 min walk test

- Isokinetic dynamometry

What is progressive overload

- The gradual increase of stress placed on the body during resistance training

Effects of targeting single joint of multi joint muscles

- Single joint: less skill dependent and may target muscle groups better

- Multi joint: may be tailored to more specific task

When to use isometric, concentric and eccentric movement

- Isometric: early post op and tendinopathy

- Concentric: power and strength adaptations

- Eccentric: tendinopathy

Exercise order guidelines

- Large muscle groups before small

- Multi joint before single joint

- High intensity before low intensity

Muscle strength progressive overload

- 1-3 sets, 1-12 reps at 80-100% of 1 rep max

- 2-3 mins rest

Muscle power progressive overload

- 1-3 sets, 3-6 reps, 30-40 % of 1 rep max

- 2-3 mins rest

Muscular endurance progressive overload

- 1-3 sets, more than 15 reps, 40-60 % 1 rep max

- Short periods of rest (less than 90)

2 for 2 rules

- If the patient can perform 2 or more reps over the assigned goal for at least 2 consecutive sets, add weight