Exercise and Physical Activity for Older Adults

Lizl van Heerden Sanette Steyn

Exercise is known to simultaneously impact and

mediate chronic disease, many impairments, functional deficits, quality of life, and cognition and prevent the negative sequelae as sociated with sedentary lifestyles.

Role of physical activityAny bodily movement that

involves skeletal muscle contraction and the substantially increases energy expenditure.

Physical activity is typically leisurely activity, requires little to no supervision, is of lower intensity than exercise, and may be thought of as usual activity

Older adults should get at least 150 minutes of moderate intensity physical activity per week as well as muscle strenghtening exercices on two or more days per week.

Physical inactivity is a risk factor for developing many chronic conditions that impact functional mobility in older adults.

Conditions like: Heart diseases Cancer Depression Hipertension Tipe 2 diabetes Obesity Osteoporoses Peripheral vascular disease Stroke Balance problems and falls

Physical inactivity also increases the risk of disability in individuals with various

chronic health conditions.Disabilities like: Chronic back pain Arthritis Frailty Debilitating illness Total joint arthroplasty Lower extremity fractures Parkinsons disease

The slippery slope of ageing

The age related loss of strength is one of the most crytical factors contributing to mobility disability and therefore greately interests physical therapists working with older adults.

The average adult strength decreases at a rate of 10% per decade starting after age 30 years accelerating tot 15% per decade after age 60 years.

Other physiological systems also decline at approximately the same rate , including the cardiac and respiratory systems , the hepatic and renal systems ,and the cognitive and sensory systems.

Because no other organ system affects mobility as directly as skeletal muscle does, the muscular system can be characterized as the entry way to frailty.

Taking into account the slippery slope of functional decline in ageing, it is appropriate to set goals that will have long-range health benefits and reduce or prevent mobility disability , physical therapists should be aware of the normative values of mobilty including usual and fast gate speed , distance walked in 6-minutes , chair rise time , stair climbing and floor rise.

Applying the appropriate principles of an exercise prescription should seek not only to return an individual to his or her previous level of function but also to increase physical reserves to return the individual to a higher level of function.

Physical stress theoryThe physical stress theory (PST)

is the predictable respons of tissues, organs and systems to mechanical and physiological stressors.

The PST explains the effect of overload or insufficient load on tissues, organs or systems as well as the lack of change in tissues, organs and systems if “usaul” stress is applied consistantly.

If too much stress is placed on a tissue it is due to injury.

If too little stress is consistantly placed in a tissue the tissue loses its ability to absorb and dissipate stresses , the tissues then atrophies.

The same then counts for the cardiorespiratory and musculoskeletal systems.

The concept of progression is also inherent in the PST.

Once the tissue, organ, system and person adapt to being able to absorb and dissipate a certain level of stressor, this level becomes the usual or maintenance level, and increased levels of stress are needed to achieve further gains.

Elements of an exercise prescription

An exercise prescription should encorporate all necessary parameters to promote the desired change to a system.

When attention is paid to appropriately manipulating the type of exercise, intensity, duration, frequency, type of contraction, speed of contaction, and concepts of motor learning, the outcome of exercise can be more accurately predicted.

Elements

1. Overload 2. Specificity3. Functional training4. Types of contraction5. Motor learning6. Frequency7. Sets8. Durations

1. OverloadOverload is the crytical

parameter needed to extend the limits of muscular performance and that appropriate intensity of exercise is needed to achieve high levels of function.

2. Specificity Specificity is achieved by

prescribing exercises that match the type of muscle contaction, the speed of contaction and consideration of the functional movement inherent in the desired outcome.

Current knowledge of specific actions of muscles involved in a movement is crytical to apply the specificity concept.

3. Functional trainingFunctional training refers to

overloading the movement or activity of interest to challenge this whole neuromuscular system rather than simply challenging a muscle.

Instead of breaking down a movement into individual muscle actions, fuctional training challenges the patient to use multiple joints through multiple axes of motion incorporating body weight and balance.

Progression of functional exercise program is obtained by moving from:

1. Simple movements to more complex movements

2. Normal speed to either quicker or slower movements

3. Stable surfaces to unstable surfaces4. Eyes open to eyes closed5. An emphasis on form to an amphasis

on intensity and the working over from base of support to working outside the base of support.

Speed and powerPower – the time rate of force

development.Speed – a necessary of certain

fuctional movements to challenge patients.

4. Types of contactionsFunctional activity can be

analyzed to detemine whether the type of muscle contraction needed to complete the activity is concentric, eccentric or isometric.

5. Motor learningMotor learning occurs with

repetition and sufficient stimulus.Repeating a movement over and

over again results in improving the patients ability to perform that movement and that movement alone.

6. Frequency Frequency refers to the number

of exercise sessions per week that are necessary or advisable to obtain optimal results.

Frequency of exercise sessions varies with the type of exercise being done.

7. Sets The recommended number of

sets of a particular exercise are 3 sets to be more effective for strength gains, rather than 1 or 2 sets.

8. Duration The amount of time of each

exercise or the length of time of an exercise session.

Typically skill and balance activities are practised 20-30 minues per session.

Aerobic exercise durations are 30 minutes , with short periods of 5-10 minutes of warm-up and cool-down.

Conclusion There are numerous variables to

consider when designing an exercise perscription :

1. Whether or not the exercise will challenge or overload a patients ability

2. Specificity of type of exercise, speed of exercise, and type of muscle contraction are full further considerations.

The creative challenge of exercise prescription is how the physical therapist manipulates

the variables to achieve the desired outcome.