Video Notes on Health, Wellness, and Physical Activity (Ch. 1-7)
Health and Wellness: Evolution of Definitions
- Original framing: health mapped to dictionary definitions; health as an endpoint (continuing existence) and wellness as the process to attain health. Overall, a clean, tidy picture where health was the goal and wellness was the path.
- Problem with evolving terminology: groups started swapping terms (e.g., switching health to “healthier,” wellness to “well-being”), creating confusion where wellness could be both the endpoint and the continuum.
- Modern framing of health: health is a point of homeostasis — the balance between demand and capacity.
- Health as adequate functioning: if you’re unhealthy, your systems cannot meet your needs; if you’re very healthy, functioning systems work so well that almost anything you try is doable.
- Health can be dynamic: you can become healthier over time, and you can be healthy yet still experience issues (e.g., mobility problems) without negating health, as long as you’re not aiming for extreme performance (like running a marathon) that your body cannot support.
- Health as a product: health is viewed as an outcome associated with other inputs; analogous to a product you buy or obtain.
- Examples of national discourse and misalignments:
- Emphasis on nutrition education for all doctors (even though nutrition is already part of medical curricula).
- Interest in universal wearables for all Americans; yet wearables can lead to decreased activity in some people.
- Behavior as part of health, but not the sole determinant:
- Social determinants matter (education level, access to healthcare, residence, transportation, safety, environment).
- Education and geographical access affect health outcomes (e.g., Michigan urban vs rural disparities in hospital access; transport times; helicopter evacuations from rural areas).
- Economic factors: employment-based health insurance with cost caps (e.g., parental coverage caps) can limit care affordability; caps may affect access to high-cost treatments.
- Social determinants and the healthcare system’s focus:
- The national discourse emphasizes behavioral determinants but may systematically cut other supports (education, safety, transportation, basic social services), risking a weaker overall product when nutrition is prioritized in isolation.
- Genetic and learned-behavior factors:
- Genetic risks vs. learned behaviors (influenced by socialization, friends, family, and social media) contribute to health outcomes; not all health is reducible to behavior alone.
- Well-being vs. wellness distinction (and how it’s taught in universities):
- Well-being: an overarching subjective evaluation of state of being (overall life satisfaction, happiness, quality of life).
- Wellness: sub-dimensions of well-being (components) that contribute to the whole; not a single dimension but a composite of multiple dimensions (e.g., physical, emotional, social, spiritual).
- Grandparents example: someone may have poor health yet high overall wellness due to life satisfaction; well-being is not simply the sum of physical health.
- Historical vs. modern conceptions of wellness:
- Michigan’s 9-dimension model is mandated in some contexts; five-dimension model often used in coursework.
- Modern view: wellness is not strictly about maximizing every dimension; balance is relative to individual values and life stage.
- The balance point changes across life stages and maturation; earlier views assumed stability, but contemporary views acknowledge state- and life-event-dependent shifts.
- Measurement challenges: surveys may not fully capture state-dependent fluctuations; re-testing may yield similar results due to response fatigue or stable responses, which can obscure true changes.
- Summary of definitions:
- Health: state of balance between demands and capacity, adequate functioning; can be viewed as a product or outcome influenced by determinants.
- Wellness: overarching subjective evaluation of state of being; composed of dimensions; balance is individual and dynamic.
- Well-being: the subjective state within each dimension contributing to overall wellness.
- Key takeaway: different fields and institutions may use historical vs. modern definitions inconsistently; expectations for consistency across disciplines vary.
Physical Activity vs Fitness: Definitions and Taxonomy
- Physical activity: umbrella term for a broad range of bodily movements that require energy expenditure beyond resting (beyond normal physiological demands).
- Examples: walking to class, writing, light housework; activities of daily living (ADL) fall under physical activity; numerous domains below.
- Fitness: an attribute or capability, akin to a “crayon” that may be present or lost; represents the outcome related to physical activity rather than the behavior itself.
- Health-related components of fitness (five):
- Aerobic (cardiovascular) fitness
- Body composition
- Muscular strength
- Muscular endurance
- Flexibility
- Performance-related components of fitness (six):
- Agility
- Coordination
- Balance
- Power
- Reaction time
- Speed
- Historical note: the labels health-related vs performance-related come from historical framing (sports/performance orientation); there is substantial overlap with everyday health and function; don’t overemphasize the labels.
- Practical example: grandparent grocery shopping may involve slower motor speed and balance issues; maintaining health-related attributes supports daily functioning and safety; overlap with performance domain is evident.
- Relationship: Physical activity is the process/behavior; fitness is the outcome/attributes that may change as a result of activity.
- Dimensions within physical activity:
- Activities of daily living (ADLs): routine tasks at home (brushing teeth, dishes, household chores).
- Occupational physical activity: work-related tasks (e.g., construction) that involve more physical work.
- Transportation: how you get to activities (walking, cycling, bus vs car).
- Leisure-time physical activity: exercise or recreational activities during free time.
- Trends in population activity (data-driven examples):
- US: relative to 1960s, a 30% reduction in overall physical activity by 2029 projections, despite increases in leisure-time activity; major declines in occupational physical activity due to changes in job types.
- In contrast, active leisure (exercise) has increased compared to 1960s; similar worldwide patterns observed (UK, China).
- Interpretation: increases in exercise do not fully counterbalance declines in occupational/total activity; overall activity remains suboptimal.
- Sedentary behavior: two conceptualizations to define and measure.
- Endpoint perspective (traditional): physical activity is a continuum from sedentary to vigorous; any low-intensity activity beyond rest is considered sedentary if below light activity; easy to measure with devices like accelerometers or smartphone data; examples include sitting, watching TV, scrolling, long periods of inactivity.
- Independent construct perspective: physical activity is its own continuum (from very light to vigorous), while sedentary behavior is a separate construct defined by wakeful sitting/reclined behavior, regardless of the rest of the day’s activity.
- Explanation of measurement nuance: endpoints focus on activity intensity thresholds; independent construct focuses on sustained wakeful stillness; both approaches have value but yield different interpretations.
- Intensity classifications using METs and HRR:
- Moderate to vigorous physical activity (MVPA): approximately
- 3 \leMET \le6 METs and/or
- 40 ext{%} \\le HRR \le60 ext{%}
- Vigorous intensity:
- MET > 6 or
- HRR > 60 ext{%}
- Light intensity:
- 1.6 \le MET \le 3.0 and/or
- 30 ext{%} \\le HRR \\le 40 ext{%}
- Note: these cutoffs come from exercise physiology conventions; different datasets may use slight variations; important to interpret in context.
- Practical measurement considerations:
- Endpoint perspective is easy to measure but may miss important contributions from non-MVPA activities and long sedentary periods.
- Independent construct perspective highlights the independent risk associated with prolonged sedentary time, even if MVPA is achieved elsewhere in the day.
- Illustrative scenarios:
- If you run 2 hours of MVPA but sit for 22 hours, endpoint perspective may not fully capture health risk; interpretation depends on measurement approach.
- If you sit for long periods but are otherwise lightly active, independent-construct views may indicate different risk profiles than endpoint views.
- State-dependence and measurement challenges:
- State-dependent changes: daily energy levels, mood, social context, life events can shift one’s activity patterns and wellness.
- Repeated surveys may produce similar responses due to response patterns, not necessarily stable wellness; measurement instruments may need sensitivity to context and time.
COVID-19 Death Data and Death Certification
- Public discourse around COVID-19 mortality has highlighted discrepancies between sources; examples cited:
- US internal statistic: about 767,000 deaths attributed to COVID-19 during the height of the pandemic.
- World Health Organization (WHO) data often shows around 1.1 million deaths globally attributed to COVID-19.
- The discrepancy is not about lying; it stems from differences in counting methods and attribution practices across databases and levels of aggregation.
- Root issues: cause-of-death attribution and coding practices.
- People worried about potential manipulation or misattribution point to debates about cause-of-death definitions and triggers.
- International classification and standardization (ICD):
- History: WHO, established in 1948, created standard definitions and a system for classifying and coding diseases to track public health data.
- ICD-11 (the 11th revision) is the current (digital) system used for diagnosis coding and data tracking.
- Objective: provide a universal framework to record diseases and causes of death for epidemiology and health system planning.
- Cause-of-death framework under ICD-11:
- Immediate cause of death: the final disease or condition that directly caused death.
- Intermediate causes: conditions that contributed to the immediate cause.
- Underlying (root) cause: the disease or condition that initiated the chain of events leading to death.
- Other significant conditions contributing to death may be recorded.
- Practical implications of ICD-11 and cause-of-death coding:
- Digital, linked coding allows more precise categorization of diseases and their subtypes (e.g., subtypes of heart failure).
- Clearer tracking of disease risk factors and their links to outcomes across populations.
- Better data for understanding epidemiological trends and evaluating interventions.
- Healthcare system and policy implications:
- Even though the U.S. is not formally a member state of the WHO, many health and insurance systems rely on WHO guidelines and ICD-11 for billing and data standards.
- Accurate coding is essential for reimbursement; incorrect codes can affect payment and coverage.
- Critics argue that withdrawal from WHO can reduce transparency and tracking of mortality causes, hindering public health responses.
- Takeaways for epidemiology practice:
- Understand both the underlying and immediate causes of death and how multiple conditions contribute to mortality.
- Recognize that data sources may differ due to attribution rules, cultural practices, and policy decisions.
- Embrace standardized, digital ICD-11 coding to enable cross-national comparisons and trend analyses.
Connections to Foundational Principles and Real-World Relevance
- Health, wellness, and well-being concepts connect to core public health and clinical decision-making:
- Definitions shape measurement, policy priorities, and resource allocation.
- Social determinants (education, access, transportation, safety, environment) influence outcomes beyond individual behaviors.
- The shift from viewing health as a static endpoint to a dynamic balance informs how we design interventions across life stages.
- Measurement and interpretation are foundational for evaluating programs, wearables, nutrition education, and screening strategies:
- Clarifying terms helps avoid misaligned goals and expectations.
- Understanding the domains of physical activity and their relationships with health outcomes informs exercise prescription and public health messaging.
- Ethical and practical implications:
- Emphasizing behavioral determinants without robust attention to structural supports can misguide policy.
- Accurate cause-of-death data are essential for transparency, research, and policy decisions.
- Data systems (ICD-11) enable better surveillance but require careful interpretation to avoid misattribution or misinterpretation of trends.
- Moderate to vigorous physical activity (MVPA) thresholds:
- 3 \,\le \, MET \,\le \, 6 \text{ METs}
- 40\% \, \le \, HRR \, \le \, 60\%
- Vigorous intensity thresholds:
- Light intensity thresholds:
- 1.6 \, \le \, MET \, \le \, 3.0
- 30\% \, \le \, HRR \, \le \, 40\%
- Endpoints vs Independent Constructs (conceptual): Endpoint perspective treats activity on a continuum from sedentary to vigorous; independent construct treats physical activity and sedentary behavior as separate continua.
- ICD-11 framework for cause of death: Immediate cause → Intermediate causes → Underlying cause (initiating cascade); digital coding supports data extraction and analysis.
Practical Study Tips for the Exam
- Be able to differentiate health as a state, wellness as a subjective evaluation across dimensions, and well-being as dimension-specific components within wellness.
- Memorize the five health-related and six performance-related components of fitness, and understand their overlap with day-to-day functioning.
- Understand the four domains of physical activity (ADL, occupational, transportation, leisure) and how population trends show reductions in some domains but increases in others.
- Explain the two perspectives on sedentary behavior (endpoint vs independent construct) and the implications for measurement and health risk.
- Know the MET and HRR thresholds for MVPA, light, and vigorous intensity, and be able to interpret them in practical scenarios.
- Be familiar with ICD-11 concepts (underlying vs immediate vs intermediate causes) and why standardized coding matters for epidemiology and health policy.
- Recognize the political, economic, and systemic factors that influence health determinants and the interpretation of health data in public discourse.
