Download Health consequences of sedentary behaviour Hypokinetic diseases

 Health consequences of sedentary behaviour
 Hypokinetic diseases – disease caused by or associated with a lack of PA
 E.g. Type II diabetes, obesity, CV diseases, some cancers, osteoporosis, back problems,
depression
 2. Types of exercise and physical fitness
 TYPES
 Health related
 Sport-specific
 Occupation specific
 COMPONENTS
 Cardiorespiratory (aerobic)
 Indicates the capacity of the body to deliver oxygen to tissues and remove metabolites
 Compromised by CV disease
 Musculoskeletal fitness
 Strength, muscle endurance =, flexibility
 Reduces injury and back pain
 Compromised by bone/joint disease, as well as neuromuscular disease
 Body composition
 Excess body fat  increased disease risk
 Lack of muscle and bone density  frail elderly
 3. Pre-exercise screening and fitness testing
 Pre-exercise screening
 Pre-exercise questionnaire
 Medical evaluations
 Musculoskeletal assessments
 ESSA
 Stage 1 – compulsory
 Determine who is at high risk (medical clearance needed before undertaking any training
program)
 Stages 2 and 3 – optional
 Determine who is at moderate or low risk
 FITNESS TESTING
 Assess health status
 Assess for sports needs
 Set training goals
 Rehabilitation
 Requirements
 Specificity
 Validity


Objectivity
Reliability
 4. Principles of exercise training and types of training
 Principles
 Overload
 Specificity
 Responsiveness
 Reversibility
 Types
 Resistance
 Endurance
 Interval
 Circuit
 5. Skeletal muscle and exercise
 MORPHOLOGICAL CHANGES
 Muscle force increases with increases in muscle size. Size increases for atleast 12
months of training, but there is eventually a limit to further increases. Taking steroids is
an exception
 Influences on the magnitude of muscle size changes
 Muscle group
 Selective area
 Fibre type
 Age
 Gender
 Training variables
 MECHANISMS OF SIZE CHANGES
 Fibre hypertrophy (bigger fibres)
 Clear evidence of muscle hypertrophy
 Increase size of fibres
 Myofibril proliferation
 Increased protein synthesis
 Fibre hyperplasia (more fibres)
 Evidence less clear. Verdict uncertain
 Fibre length
 Evidence unclear. Difficult to establish
 FLEXIBILITY AND MUSCLE LENGTH
 Muscle length can limit flexibility. Insertion of more sarcomeres in fusiform muscles
could increase muscle length.
 Loss of elasticity contributes to reduced flexibility
 Skeletal muscle cells are multinucleated. Fibre myofibril content is proportional to
myonuclei
 Type II fibres ~ 2X myofibrils per nucleus of type I fibres