Chapter 11 : Development of Strength and Flexibility

Muscular strength and endurance are ____________ fitness components that may improve or maintain: ​

health related

Bone mass​

Muscle mass​

Glucose intolerance​

Musculotendinous integrity ​

Ability to perform activities of daily living​

Fat Free Mass​

What is Muscle Mass

Sigmoid growth pattern ​

Sex differences minimal until puberty ​

Minimal changes during adulthood up to 50, then decline​

Muscle Strength is the ability to

exert force

Different types of muscle strength

Isotonic, Isokinetic, and Isometric

Isotonic

Exertion of a force against constant resistance through the range of motion of a joint ​

• bench press

Isokinetic

Exertion of force at a constant limb velocity through the range of motion of a joint ​

• clinical setting (keeps at the same speed doing same movement)

Isometric

Exertion of force without a change in muscle length ​

Different ways to assess strength

Isotonic : 1Repetition Max (1RM) of a free weight​

Isokinetic : Machine where speed is constant ​

Isometric : Dynamometer ​

Functional Tests : Chin-Ups, Flexed Arm Hang​

​

Developmental Strength in youth : Strength ____ as children grow

increases

• strength is related to muscle mass

Strength levels of boys and girls are similar until age

13

Development Strength - Youth : Maturation

of the Nervous System ​

The development of muscular strength in childhood is ​

controversial

Can children increase their muscular strength through participation in a program? ​

as long as adults are teaching them the right ways, they should be fine

Strength Training – Youth ​ (Fritz and Coleagues (2016))

Musculoskeletal effects of physical activity​

Children (6 – 9 yrs. old) ​

7-year period

What were the results of Fritz and Colleagues Strength Training for Youths?

Results: The children in the intervention group gained more muscular strength than the children in the control at the end of the 7 years ​

• knee flexion strength

• Tibia Cortical Thickness

• Additionally, girls experienced an increase in spinal bone mass ​

Strength is not related to

muscle mass/size alone

__________ training programs effective an enhancing motor skill performance ​

Resistance

Younger children can demonstrate ______ gains in performance than adolescence (Behringer et al., 2011)​

greater

Change in adolescent around 14

• comparison in gender differences

• boys have a lot more testosterone

Greater effect of strength training learning for an

unlearned and untrained individual ​

Youth strength training ____ ____ prevent injury among at risk youth: physically inactive​

may help

______ ______ of children and adolescents training is key ​

close supervision

Resistance training programs are effective in enhancing

motor skill performance ​

• Children and adolescence can improve muscular strength ​

• Physical activity Interventions

What negative effects could strength training cause in youth

Susceptible to injury

Traumatic Injury

Adolescent workouts should be no more than

8-10 exercises

Intensities : body weight exercise choices

Resistance training : <80% of 1RM

Sets and Reps : 1 to 3 sets ( 6-12 reps)

When movement patterns develop, you should

add more exercise

What are the performance benefits of Resistance Training for Youth?

What are the health benefits of Resistance Training for Youth

For development of strength in adults, there is

sex differences

• muscle mass

• slow twitches and fast twitches (woman have less type II)

cultural norms

differences are not strictly biological

Strength levels are __________ throughout 20s and 30s ​

maintained

Isometric and Isokinetic strength __________​

decline

• nervous system

There is a decrease in _________ in the muscles for adults

capillaries

Child Workouts

Should be no more than 8 – 10 exercises ​

Intensities should be ​

• Body weight exercise choices ​

• Resistance training <60 1RM ​

• Sets/Reps​

• 1 to 2 sets ​

• No more than 10 repetitions​

Strength training is beneficial to

young and middle-aged adults

Adults over ___ can increase muscle strength training

60

• 60-85% of their maximum voluntary strength ​

• 3 – 4 times a week ​

High and Low volume training is ______ ​

benefical for adults

Silva et al. (2014) found that the longer the training program duration for older adults

the greater the strength gains

After the growth period ceases, increases in muscle mass are associated with ________________​

resistance training

Are there long term or short term effects of anabolic steroids in adults

short term : increase blood pressure, acne, increased tendon tears

long term : increased death, disorders, cardio vascular..

Summary of Strength Changes - Aging​

What is flexibility

The ability to move joints through a full range of motion ​

Range of motion (ROM) possible at any joint depends on that

joint bone structure and the soft tissues remnants to movement​

Assessing Flexibility includes

Sit-and-Reach Test ​

Shoulder reach Test ​

Goniometer ​

Very joint specific ​

​

Flexibility among children is ____ but it ______ in older children ​

high but declines

Soucie and colleagues (2011) measured the average range of motion for 4 age groups ​

Age 2 -8 (Greater range of motion) ​

Age 9 – 19 ​

Age 20 – 44 ​

Age 45 – 69 ​

McKay and colleagues (2017) also measured range of motion for 4 age groups and found small sex differences - AUS​

Ages 3 – 9​

Ages 10 – 19 ​

Ages 20 – 59 ​

Ages 60+ ​

There is _____ _____ in youth and decrease in age​

greater flexibility

Differences between boys and girls for flexibility ?

• Stretching exercises are more valued in other societies, culture ​

• Activities that require flexibility are more acceptable for both boys and girls ​

Flexibility training in youth has

limited research

• flexibility/stretching program

• training WORKS

Flexibility declines from the mid to late ____

twenties

• occurs faster in some joints

What are causes of loss of flexibility in adults

Osteoarthritis

Osteoporosis

Degeneration of Tissues

Disuse/Inactivity

Training can maintain range of motion in those with

full range

Training can improve range of motion in those with

limited range ​

RECOMMENDATIONS FOR DEVELOPMENT OF STRENGTH AND FLEXIBILITY​

Muscle-strengthening: As part of their 60 minutes or more of daily physical activity, children and adolescents should include muscle-strengthening physical activity on at least THREE a week​

How much activity does adults need?

As part of their weekly physical activity, older adults should do ______ ______ ________ that includes balance training as well as aerobic and muscle-strengthening activities.​

multicomponent physical activity

The younger you are, the greater

ROM you have