11/26/2013

Exercise Dosage How to properly prescribe the single-most beneficial medicine ever created Brian Riddle, DPT, OCS, ATC, CSCS

Objectives

Are physical activity and exercise identical?

• Observe the interplay of and differentiation between physical activity, exercise and therapeutic exercise • Defend why exercise is medicine and become competent in the basics of exercise prescription • Identify client barriers to exercise and discover the motivating factors behind the psychology of human behavior

Definitions

“Physical activity" should not be mistaken with "exercise“ (WHO) • Physical activity • Exercise as well as other activities which involve bodily movement and are done as part of playing, working, active transportation, house chores and recreational activities

• Exercise: • Intentional, planned, structured, repetitive & purposeful physical activity for improving health and fitness beyond ADLS (ACSM & WHO)

Definitions (cont.)

• Physical therapy • diagnosis and management of movement dysfunction and enhancement of physical and functional abilities; restoration, maintenance, and promotion of optimal physical function, optimal fitness and wellness, and optimal quality of life as it relates to movement and health; and prevention of the onset, symptoms, and progression of impairments, functional limitations, and disabilities that may result from diseases, disorders, conditions, or injuries

Therapeutic exercise • systematic performance of planned physical movements, postures, or activities intended to enable the patient/client to: • remediate or prevent impairments, • enhance function, • reduce risk, • optimize overall health, and

Guide to Physical Therapist Practice 2003.

• enhance fitness and well-being.

Guide to Physical Therapist Practice 2003.

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Muscle Slings

DOES EXERCISE DOSAGE REALLY MATTER?

Twenty Leading Causes of Death Among Persons Ages 10 Years and Older in US

www.cdc.gov

“All parts of the body, if used in moderation and exercised in labors to which each is accustomed, become thereby healthy and well developed and age slowly; but if they are unused and left idle, they become liable to disease, defective in growth and age quickly.” Hippocrates (~400 BC)

Increased physical activity, increased lifespan

Moore SC. PLOS Medicine. 2012

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Tissue Reponses Injury

Immobilization

Activity

Bone

Failure on tensile side of force, regeneration

Lose density

Hypertrophies, Wolf’s Law

Muscle

Denervation or inhibition of fibers, atrophy

Contracture and atrophy

Hypertrophy and increase number of cells

Tendon

Thickening through acute inflammation or degenerate through chronic overload

Disorganization of fibers and adhesions

Increase thickness and strength

Cartilage Degeneration through external force or inflammation

Adhesions, wasting, less water and protein content

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Ligament Elongation or rupture

Weakened

Thicker, stronger and stiffer

Nerve

---

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Irreplaceable, except PNS depending on proximity to cell body

EXERCISE DOSAGE PRINCIPLES

Physical Stress Theory

Exercise Prescription & Dosage

• Application of exercise science to prescription (Mueller MJ

• Parameters & variables include…

& Maluf KS, 2002)

• Principles include… • Overload (Moffroid & Whipple, 1970) • Specificity (Sale, 1988; Cronin JB, 2002) • Progression • Recuperation / recovery • Use / disuse

• • • • • • • • • • •

Type of contraction Intensity Volume Speed Duration Rest periods Frequency Sequence/order Environment Feedback Exercise selection

Hall & Brody, 2005; Baechle & Earle, 2000

Multiple vs. Single Sets • One set per exercise (after warm-up) performed to volitional muscular failure is sufficient to maximize gains in muscular strength and hypertrophy (Alen et al, 1988; Brzycki M, 1988; Graves et al, 1988; Jones A, 1971, Luthi et al, 1986; Marcinik et al ,1991; Wescott WL, 1986)

• Single-set training is appropriate for untrained individuals or those in the first several months of training (Fleck, SJ & Kraemer WJ, 1997; Graves et al, 1988) • Higher volumes are necessary to promote further gains in strength, especially for intermediate and advanced resistance-trained athletes (Kraemer WJ, 1997; McGee et al, 1992; Stowers et al, 1983; Willoughby, DS, 1993)

RESISTANCE EXERCISE

• The musculoskeletal system will adapt to the stimulus and require a different stimulus to bring about continued strength gains (Fleck, SJ & Kraemer WJ, 1997)

• Due to inconclusive reports in many studies, nearly any type of program will cause improvements in strength for untrained subjects (Baechle & Earle, 2000)

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Training Load & Reps %1RM

# of reps allowed

100

1

95

2

93

3

90

4

87

5

85

6

83

7

80

8

77

9

75

10

70

What about resistance training?

Experienced 80%+ 1RM

11 Novice – Intermediate 60-70% 1RM

67 65

12 Beginners & older 4050% 1RM

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Peterson, JSCR, 2005

Baechle & Earle, 2000

Can there be too much of a good thing?

Resistance Exercise • Frequency – each muscle group trained 2-3 d/wk • Intensity • Strength • 60-70% 1RM (mod to hard) for novice to intermediate exercisers • ≥80% 1RM (hard to very hard) for experienced strength trainers • 40-50% 1RM (very light to light) for older persons or sedentary persons beginning an exercise program

• Muscular endurance -