Physical Activity, Physical Fitness, Exercise, and the Fitness Professional: Comprehensive Study Notes

Physical Activity (PA): Defined as any bodily movement produced by the contraction of skeletal muscles that results in an increase in caloric requirements over resting energy expenditure.
Exercise: A specific type of physical activity consisting of planned, structured, and repetitive bodily movement. It is performed deliberately to improve and/or maintain one or more components of physical fitness.
Physical Fitness: A set of attributes or characteristics that individuals have or achieve. These attributes relate to the individual's ability to perform physical activity and activities of daily living (ADLs).
Health-Related Physical Fitness (HRPF): These are components of fitness specifically associated with public health. They include:
- Cardiorespiratory fitness.
- Muscular strength.
- Muscular endurance.
- Flexibility.
- Body composition.
Skill (Sport)-Related Physical Fitness: These are components related to athletic ability and performance rather than strictly health outcomes. They include:
- Agility.
- Speed.
- Coordination.
- Power.
- Reaction time.

Physical activity exhibits a linear relationship to health; as activity increases, health benefits generally increase.
Exercise is a sub-category of physical activity that is goal-driven, purposeful, and structured.
Engagement in exercise is necessary to achieve physical fitness.
Role of Genetics: Genetics plays a role in determining the baseline or potential level of physical fitness an individual can achieve, but exercise training is required to maximize that physical fitness potential.
Practical Examples of HRPF in Daily Life:
- Hiking: Requires cardiorespiratory fitness, muscular endurance, and body composition.
- Yard Work: Requires muscular strength, muscular endurance, and flexibility.
- ADLs: Activities of daily living generally require an energy expenditure close to $5.0\,\text{METs}$ .

Definition: The metabolic equivalent of task (MET) is a physiological measure used to express the energy cost of physical activities as a multiple of the resting metabolic rate.
Reference Value: One MET is defined as the energy expended while sitting quietly. This is equivalent to an oxygen consumption of $3.5\,\text{mL/kg/min}$ (milliliters of oxygen per kilogram of body weight per minute).
Intensity Categories and Thresholds:
- Sedentary: < 1.6\,\text{METs}. Activities involving lying or sitting with low energy requirements.
- Light: $1.6$ to $3\,\text{METs}$ . Intensity can be sustained for $60\,\text{mins}$ and does not affect breathing rate.
- Moderate: $3$ to $6\,\text{METs}$ . Aerobic activity where an uninterrupted conversation can be held. This can be performed for $30$ to $60\,\text{mins}$ .
- Vigorous: $6$ to $9\,\text{METs}$ . Intensity that cannot be maintained without compromising speech and conversation. This can only be maintained for $30\,\text{mins}$ .
- High: > 9\,\text{METs}. Intensity that generally cannot be sustained for more than $10\,\text{mins}$ .

Improvement in Cardiovascular and Respiratory Function:
- Increased maximal oxygen uptake resulting from both central and peripheral adaptations.
- Decreased heart rate and blood pressure at any given submaximal intensity levels.
Reduction in Cardiovascular Disease (CVD) Risk Factors:
- Reduced resting systolic and diastolic blood pressure.
- Increased serum high-density lipoprotein (HDL) cholesterol.
- Decreased serum triglycerides.
Decreased Morbidity and Mortality:
- Higher activity and fitness levels are associated with lower incidence rates for coronary artery disease, stroke, combined cardiovascular diseases, and many other chronic diseases.
- Cardiorespiratory Fitness (CRF) is a significant and independent predictor of all-cause mortality.
Psychological and Cognitive Benefits:
- Decreased anxiety and depression.
- Improved cognitive function.

General Recommendation: Move more and sit less throughout the day.
Types of Training: Both aerobic (endurance) and muscle strengthening (resistance) training are necessary for health benefits.
Substantial Benefit Guidelines:
- Perform at least $150\,\text{min} \cdot \text{wk}^{-1}$ of moderate-intensity activity, OR
- Perform at least $75\,\text{min} \cdot \text{wk}^{-1}$ of vigorous-intensity activity.
Extensive Benefit Guidelines:
- Perform at least $300\,\text{min} \cdot \text{wk}^{-1}$ of moderate-intensity activity, OR
- Perform at least $150\,\text{min} \cdot \text{wk}^{-1}$ of vigorous-intensity activity.
Muscle Strengthening: Perform activities involving all major muscle groups on $2$ or more days per week.

Purpose of Measurement:
- Educating participants regarding their fitness status relative to age- and sex-matched norms and health standards.
- Providing data to develop individualized exercise prescriptions.
- Collecting baseline and follow-up data to evaluate progress.
- Motivating participants via attainable fitness goals.
Crucial (VO_2) Max Cutoffs and Norms:
- Heart Failure Survival: A peak $VO_2\text{max}$ of $14\,\text{mL/kg/min}$ is the cutoff for survivors vs. non-survivors.
- ADL Independence: A cutoff of $18.3\,\text{mL/kg/min}$ is needed to avoid requiring assistance with activities of daily living.
- Full Independence at Age 85: Men require $17.7\,\text{mL/kg/min}$ and women require $15.4\,\text{mL/kg/min}$ .
- Average College Male: Approximately $40\,\text{mL/kg/min}$ .
- Athletes: Range between $60$ to $70\,\text{mL/kg/min}$ .
Fitness Status and Mortality Studies: Significant research proving the link between fitness and health includes studies by Lakka, Sandvick, Blair, and Ekelund.

Academic Pathways: Many universities offer degrees in Exercise Science, though titles and specific curricula vary.
Accreditation Bodies:
- CAAHEP: Commission on Accreditation of Allied Health Education Programs.
- CoAES: Committee on Accreditation for the Exercise Sciences (established in 2004 with CAAHEP support).
ACSM (American College of Sports Medicine):
- Provides the most widely recognized certification programs.
- Offers both health fitness and clinical types of certifications.
- Certifications are accredited by the NCCA (National Commission for Certifying Agencies).