THE PHYSIOLOGY OF FITNESS The body’s response to acute exercise Part Three: Musculoskeletal Response

Session Outcomes List two responses of the musculoskeletal system to acute exercise Describe the processes involved in one response of the musculoskeletal system Explain why the process occurs and the benefits it generates for exercise

Recap : Responses to physical activity Can be acute or chronic Acute – body’s immediate responses to exercise Chronic – adaptations to the body that occur through regular training

Responses to physical activity Musculoskeletal responses: Increased blood supply Increased muscle pliability Increased range of movement Muscle fibre tears

Musculoskeletal system Consists of muscles, tendons, ligaments, bones and cartilage. Their function is to support and move the body (posture) The system is controlled by the nervous system to produce voluntary movement. Nerve impulses cause muscles to contact LINK http://www.youtube.com/watch?v=7Rzi7zYlW no

Musculoskeletal system Muscle tissue has four main properties: Excitability (ability to respond to stimuli) Contractibility (ability to contract) Extensibility (ability of a muscle to be stretched without tearing) Elasticity (ability to return to its normal shape).

Individual task What acute responses have occurred in your musculoskeletal system? Identify responses and try to explain why you believe these responses have occurred.

1. Increased blood supply Increase in temperature and metabolic activity. Muscle contraction produces heat and as much as 70% of body heat is produced by energy production in muscle tissue (Shivering !!) The greater demand for oxygen is met by an increase in blood supply through capillary dilation

2. Increase in muscle pliability KEY TERM: Pliability – relates to the stretchiness of your muscles and connective tissue. Question: Muscle damage – increase or decreased risk when warm? Warming of muscles makes them more pliable and reduces the risk of injury and damage – natural response

3. Increased range of movement KEY TERM: Viscous: the measure of resistance (thickness) of a fluid. Acute responses to the skeletal system is demonstrated by changes within the joints Joint movement stimulates the secretion of synovial fluid The fluid becomes less viscous and the R.O.M. at the joint increases

4. Muscle fibre micro tears The stress placed on your muscles during exercise leads to tiny tears in the muscle fibres The tears will cause swelling in the muscle tissue, this creates pressure on the nerve endings and pain Training improvements will only be made if the body has sufficient fuel and rest to repair the micro tears. Repair of the tears will make the muscle a little bit stronger than it was before

Session Outcomes List two responses of the musculoskeletal system to acute exercise Describe the processes involved in one response of the musculoskeletal system Explain why the process occurs and the benefits it generates for exercise

TASK In pairs you are to produce a poster presentation of an elite athlete showing acute responses to their activity? Cardiovascular responses Respiratory responses Musculoskeletal responses Energy systems used

Practical Practical Task in groups of 4 You are to plan exercise in the sports hall for each main energy system. Cp energy system -10s ‘explosive’ 1 min rest intervals Lactic acid energy system 60-90s ‘high intensity’ 3min rest Aerobic energy system 2min+ Plan how you can record acute responses to these activities