What did the gene pool evolve from and what did humans develop?
- Gene pool evolved from hunter-gatherer lifestyle; physical activity required for food procurement
- Humans developed “thrifty genes” – genes that maximise metabolic efficiency
- Little change in human gene pool over 10 000 years
What is thrifty storage?
Replenish skeletal muscle glucose and TG: more efficient storage of excess glucose and TG in adipose tissue.
What does more thrifty storage equal?
More likely to survive through the next famine/activity phase until next feast.
During a famine or activity what happens?
Decrease in glycogen and TG stores.
What occurs during the feast?
Intake of glucose and fat
What occurs in the stalling of a famine or activity?
- No cycling of metabolic processes= fuel gets shunted into an even greater and unhealthy storage.
- Feast= Unlimited food supply with no exercise
- Thrifty storage exists but famine and physical activity are not utilised
What is the result of evolution on energy expenditure?
-Average energy expenditure of modern humans is 38% of H-G ancestors
How do you find out the current health status of the population?
-How do we find out? o Large scale surveys -Phone surveys -Need to be quick -Need to be easy for the participant to answer
What are METs?
- Another method to estimate intensity
- MET’s (metabolic equivalent) denotes the energy required to complete a task/activity
What do we need to perform activity and what does 1 MET equal?
-We need O2 to perform activity, thus measuring oxygen consumption is the gold standard for measuring energy expenditure
o 1 MET = 3.5 ml/kg/min-1
-Ainsworth et al. (2000) has calculated the MET’S associated with a variety of different activities:
EXAMPLE
-Boxing in a ring (77 kg) = 17.1 METS
-Axe chopping (77 kg) = 22.9 METS
-Playing a Flute (77 kg) = 2.7 METS
What is the purpose of surveys in Australia?
-To inform Australia’s decisions by providing objective, trusted and relevant data and statistics on a range of matters including economic, social and population.
What is the World Health Organisation?
- “Direct and coordinate international health within the united nations system” (WHO website)
- Provide global statistics
What is the global inactivity percentages and where is it most prevalent?
-2008 – 31% of adults ≥ 15 were inactive
o Females = 34%
o Males = 28%
o Highest in Americas and Eastern Mediterranean
o Lowest in South East Asia
In the National Health Survey what was the percentage of inactivity, insufficiently active and what is recommended?
- Recommended Level of PA = 55.5%
- Insufficiently Active: 30%
- Inactive: 15%
In the Australian Health Survey what were the results?
- 1/3 of children and 1/10 young people did the recommended 60 minutes of activity per day
- 60% of adults did less than recommended
What is inactivity?
-Not meeting the current recommendations for physical activity
o Less that 30 minutes of moderate intensity physical activity on most days of the week (< 150 min/week)
Why are people inactive?
-Why?
o Decrease in the amount of leisure time physical activity
o Increase in sedentary time in occupational and domestic duties
What is the Health Burdon of Inactivity?
-Chronic inactivity is physiologically abnormal
o Human bodies fail to function properly to maintain health in many different ways when there is a loss of adequate amounts (historically ‘‘normal’’ amounts) of physical activity
Define morbidity, mortality, all cause mortality and disease.
- Morbidity – a diseased state, the existence of disease
- Mortality – subject to death
- All-cause mortality – all deaths that occur in a population
- Disease – a disorder of structure or function in a human that produces specific symptoms
Define chronic disease and non communicable disease.
-Chronic disease – a disease that persists for some time or has long lasting effects (more than three months)
o E.g. asthma, cancer, diabetes, arthritis, HIV/AIDS, multiple sclerosis
-Non communicable disease – condition or disease that is not caused by infectious agents (non transmissible).
o Can be chronic
-E.g. Chronic kidney disease, diabetes, asthma, Alzheimer’s
What is the global burdon of inactivity?
- Inactivity attributed to 3.2 million deaths in 2008
- Physical inactivity = 4th cause of death due to non-communicable disease = 3 million (6%) preventable deaths every year
How is burdon measured and what is it calculated as?
-For the individual:
o Morbidity and mortality are measured using the Disability-Adjusted Life Year (DALY)
-One DALY is a lost year of ‘healthy’ life
o DALY = YLL + YLD
o YLL = Years of Life Lost
o YLD = Years Lived with Disability
-Calculated as a combination of years of life lost due to premature mortality and equivalent ‘healthy’ years of life lost due to disability (morbidity)
For society what is the economic burdon of inactivity?
-Economic burden – Cost $$$$
o Direct costs – associated with utilisation of healthcare resources, largest component is the cost of hospital admissions
o Indirect costs – premature retirement, absenteeism, carer costs
What are Co-Morbidities of Inactivity?
-Modifiable risk factor for mortality and chronic disease
o Physical fitness vs physical activity= strong relationship with health outcomes
o Steeper for physical fitness
