Scientific evidence for the benefits of walking and physical activity – and how to take the “next steps”

Scientific evidence for the

benefits of walking and

physical activity –

and how to take the “next

steps”

CHD

mood, anxiety, QOL, depression, socialbenefits,mental health

PhysicalActivity

Other possiblehealth benefits?prostate Ca. ?lung disease?breast cancerarthritis

diabetes colon cancerosteoporosis

BMI

BP

Cholesterol

Health benefits of physical activity

Stroke, CVD

0

20

40

60

80

100

1 3 5 7

Sandvik et al Ekelund et al Leon et alBlair et al Pafferbarger et al

CV

D M

ort

ality

, R

ela

tive

Ris

k

Level of Physical Fitness or Activity

Overall summary

Relative Risks (RR) of Total Mortality According to Level of Physical Activity Among 40 417 Post-

menopausal Women in Iowa, 1986-1992

Physical Activity Deaths Person-Years

Risk of death

Freq. of walking Rarely/never 722 55404 1.00 1/wk 621 76318 0.71 2-4 times/wk 560 82633 0.63 >4 times/wk 365 55973 0.59 Physical Activity Index Low 1309 126545 1.00 Medium 519 74170 0.77 High 415 67138 0.68

Nurses health study n=72,488 [>10 year

f/up] Walking and risk of CHD

Manson J, NEJM 1999;341:650-8

50

60

70

80

90

100

0 1 hr 3 hrs 7 hrs 10 hrs

time walked per week

Honolulu Heart health : walking & CVD risk

Elderly males

N=2678

Followed for 4 yrs

Hakim AA, Circulation 1999:100:9-13

Walking and CHD (Hakim 1999)

Effects on other risk factors

• Hypertension

• Lipid levels, HDL:total chol ratio

• Overweight and obesity – need 1 hour /day walking

Physiological benefits of walking

• Moderate to Brisk walking

• May help cardiovascular training

• strength, flexibility

• energy/expenditure

• lower injury incidence than most other physical activity (Powell 1998)

Metabolic effects of walking

• Bone density?

• Muscle strength

• influences HDL cholesterol

• improves glucose metabolism

• reduces risk of acute thrombosis

• ?immuno-potentiation

Social and Psychological benefits

• Social activity

• Sense of well being, positive mental health, reduces anxiety

• Sense of community

National Recommendations for physical activity

• every adult should accumulate at least 30 mins + of moderate intensity Physical activity on most days

• can be accumulated in short bouts, intermittently

• use opportunities in everyday life

Burden of disease and injury in AUSTRALIA

AIHW November 1999

• Building on Global BOD study Alan Lopez et al (WHO 1993)

Uses DALYs as a metric

• Comparable across countries

• Useful for assessing health burden

What is the contribution of PA?

• Compared to other risk factors

• Overall to the “burden of disease”

• What conclusions can we draw from this about PA and its positioning among risk factors ?

8.5

6.8

5.4

4.8

- 3

4.3

2.7

2.6

1.8

1.7

0.9

-4 -2 0 2 4 6 8 10

tobacco

phys activity

hypertension

alcohol harm

alc benefit

obesity

low fruit/veg

cholesterol

illicit drugs

occupation

unsafe sex

Percent of total DALYs

Percent of total burden attributed to risk factorsBoD study, AIHW 1999

The health costsof physical inactivity

Introduction

• direct costs (of health care)

• indirect costs (cost productivity)

• intangible costs (QOL)

• economic sector factors beyond the scope of costing studies

28.2 2829.9

13.9

05

101520253035

high moderate low sedentary

Category of level of physical activity

Percent

Australian adults : physical activity levels, November 1997

Mortality attributable to physical inactivity, Australia, 1996.

Disease Deaths 1996

No. attributable to physical activity

Coronary Heart Disease

29637 5335

NIDDM 2991 380

Colon Cancer 3541 680

Stroke 12806 2049

Breast Cancer 2623 228

DIRECT Costs of six major diseases attributable to physical inactivity ($

million)

161

16

101

56.2

27.5

15.7

0 30 60 90 120 150 180

heart disease

Colon Ca

NIDDM

Breast Ca

Stroke

Mental Health

Costs of inactivity ($ millions)

Effect of increasing physical activity on health costs avoided from Coronary Heart Disease

Indicator Proportion of Adult Australianswho are Sufficiently Active

56% 61% 66% 100%

Person years gained(<70 years) from CHDdeaths avoided

6465 13311 55144

A.M.I hosp admavoided

558 1149 5906

CHD health care costsattributable to PA ($m).

161 148 130 0

Potential CHD healthcare savings fromincreased PA ($m).

13 31 161

Potential Savings of Direct Health Care Costs from increased P.A., 1993/94 ($m)

Disease Proportion of Adult Australianswho are sufficiently active

61% 66% 100%

CHD 13 31 161

Stroke 10 20 101

NIDDM 3 6 28

Colon Cancer 2 3 16

Breast Cancer 2 4 16

DepressiveDisorders

6 12 56

Sub-Total 36* 76 378All Causes 439 1003 5651

Recent trends in Australia

63.4

59.6

57.6

61.1

53.8

56

62.2

56.6 56.8

40

45

50

55

60

65

1997 1998 1999 2000

Pe

rce

nt

me

eti

ng

SG

R le

ve

l Men Women Total sample

TRENDS in PA in Australia: % meeting recommended levels

13.714.6

17.5

13.114.7

13.113.414.6 15.3

0

5

10

15

20

97 99 2000

% s

eden

tary

Men Women Persons

Completely sedentary (Nat PA surveys, Australia, November 1997, 99, 2000

Relevance of walking to physical activity

promotion• Accessible to all (equity)

• few age, gender seasonal restrictions

• initial activity most easily adopted

The ‘share’ of walking and other activities from Australian adults aged over 40

MVPA26%

Walking

74%

Physical Activity Interventions more likely

to succeed if:• Not “facilities” or “program attendance”

based – adherence wanes over time

• increased routine or incidental physical activity

• include environmental change - “making walking an easier choice”

Risks of Activity - [i] Cardiac and [ii]

Injury

• cardiac events and injury increased slightly in vigorous activity

• Injuries when running - up to 35-65% p.a.

• very low risk - walking, gardening <1% p.a

The evidence is very good for

health benefits of walking and

physical activity

“Walk a mile per day” (1.6 km)

• Achievable strategy for most people

• expend about 2 mega joules/week

• without any extra energy intake, would consume enough energy for 3 kg weight loss/year

Walking project in RockhamptonQueensland Govt, 2001- 2002 Investment $ 800,000

Other [beyond health] issues in promoting

walking• ecological impact of reduced car use

• increased DOT/ public transport usage

• Social well being / social capital strategy

• community growth – shops, restaurants

• urban planning – fits into designs for sustainable urban growth

• increased recreation / leisure sector

• walk to schools - PA among children

What to do next ?

NEW SOUTH WALES, Australia, 1996-2002

The NSW Premier’s Physical Activity

Taskforce

NSW Physical Activity Task Force

• An intersectoral [inter agency] and whole of Government strategic approach to the promotion of physical activity in NSW

• Partners : NSW Health, Sport and Recreation, Education, Local Government, Fitness Industry, Heart Foundation,, DUAP, DOT, RTA

NSW PATF achievements

• International model for strategic planning for PA

• Achieved major goals in PA when focused programs 1998-2000

• prevented national decline in PA – ONLY in NSW

NSW PATF : future• Existing PATF infrastructure and network

will continue for future programs

• After 5 years, undergoing a strategic review March- April 2002

• current review will suggest clear need for future integrated program directions

• Needs program resources – never had any to date [a remarkable model, but not sustainable in the climate of PA decline]

Conclusions• physical inactivity, and especially

walking is an issue for all in NSW

• infrastructure exists in NSW – PATF – to assist with PA interventions

• needs the commitment and political will to move (forwards)