• with age, exercise less - even from freshman vs senior in college
• young more active than poor
• wealthy more active than poor
• whites more active than other ethnicities
• more educated more active than less educated
• men exercise more than women (and do more vigorous activity)
• people who are married, employed, and have kids work out less

reasons to be inactive

time

• lack of time is most frequently cited reason for not exercising
• but those who cite lack of time actually perform more hours of activity than those that don't list it at all
• people do actually tend to have enough time than they believe they just spend it in other ways

reasons to be inactive

energy

• typically more mental than physical
• exercise can help improve energy levels
• particularly low intensity
• frequent, short, low impact activity can be just as effective as a long, formal workout

reasons to be inactive

inconvenience/lack of facilities

lack of skill

• sedentary & active people had an equivalent # of exercise facilities within a 2-5 kilometer drive
• can do something you know how to, join a gym & get a trainer, ask a friend, use internet, work out at home

reasons to be inactive

health/injury

cost

• people in poor health could benefit the most
• injuries shouldn't preclude from participating in ALL forms of activity
• lifestyle exercise & walking programs cost next to nothing
• cost of poor health typically outweigh cost of exercising

reasons to be inactive

lack of motivation

safety/bad weather

• often tied to an imbalance in the perception of the rewards of exercise vs. the perceived costs
• drive to park in a better neighborood, exercise in home or yard, mall walks, gym

reasons TO be active

appearance/weight loss/weight control

• #1 reason given for starting an exercise program
• weight loss improves appearance, health, self-esteem, quality of life
• exercise best when combined with diet for weight loss, not effective alone
• weight loss takes a while so rewards are delayed
• people that use this reason enjoy exercise the least

reasons TO be active

health & fitness benefits

• physical activity increases strength, stamina, flexibiility, coordination, mobility
• physical activity decreases obesity, diabetes, risk of cardiovascular diseases, incidence of most types of cancer, risk of fall in ederly

reasons TO be active

stress reduction

enjoyment

• people who have been active for >6 months scored significantly higher for stress reduction and revitalization as a motivator for exercise than those that have been active for <6 months
• exercise can be playful, exciting, distracting, and fun
• exercise may be biggest reason why people maintain a physical activity program

reasons TO be active

socialization

competence/challenge/self-esteem

SOCIALIZATION

• excellent way to meet new people, make friends or find romantic partners, spend quality time with people,
• experience affiliation and competition (top reason why college students participate in sports)
• socialization also another major reason why people maintain an exercise program

competence/challenge/self esteem

• improves body image
• provides feeling sof astisfaction, accomplishment, mastery
• increases self-confidence
• adherents to exercise programs score higher in competence as a motivation than non-adherents

• longer legs, bigger Achille's tendons, larger gluteal muscles = increase efficiency & stability of running in humans compared to apes
• tendon acts as spring & uses less energy
• larger gluteal muscles keeps from falling, contract power falling when running
• nuchal ligament holds head steady during running (back of neck - connects head to neck)
• (watery) sweating allows humans to run without compromising heat dissipation ~ hairlessness
• but these also have other functions/benefits

• scavenging - getting to a dead animal first, some scientists believe we were scavengers for hundreds of thousands of years
• persistence hunts - chasing animals until they get overheated and used by some hunter-gatherer societies (but not most)
• however it is aslo done infrequently
• acute exercise increases positive mod and activates reward pathways
• running ncreases endocannabinoid levels in species that run but not in species that don't run

• lots of low to moderate intensity activities - walking - very little vigorous activity (produce largest increases in positive mood, increases blood endocannabinoid levels)
• a variety of low,moderate, and vigorous activities each week rather than the same thing every day
• a pattern of bursts of activity interspersed throughout the day with plenty of rest
• highly social/interactive, goal directed and required skill and knowledge

Exercise & Anthropological Hypothesis of Depression

Also BOredom

• within last 50-75 years, humans haven't need to do as much physical activity to survive
• may explain why depression rates have skyrocketed since early 20th century
• when physical activity is not social or goal-directed, the exerciser may not be intellectually stimulated as ancestors were

• evolution shaped by scarcity of food rather than surpluses
• tendency toward sedentary behavior as ameans ot conserve energy
• meditation techniques that promote relaxation and non-activity have been shown to increase dopamine release

• twin studies show between 0-85% of variation in physical activity is inherited
• large differences may reflect differences in population characteristics or study design (how physical activity was measured)
• obligatory activity (activity required for continued survival of the organism or species) have a larger biological and genetic component because they are necessary for continued survival

Hypothalamus

basic functions

• different nuclei in the hypothalamus receive extensive input from sensory & internal sources regarding temperature, energy/hunger levels, osmolarity/thirst (hydration status), light and other circadian cues, sexual stimuli, threats, etc
• these nuclei then connect to many other brain/cotrical strutures that influence behavior, most notably the prefrontal cortex
• initiates goal directed behaviors, movement goals & plans

Hypothalamus

LH

VMH

• lateral hypothalamus - hunger and thirst circuit & triggers increased activity behaviors tailored to acquiring food & water and lesions to it decrease these activities
• ventromedial hypothalamus - part of the satiety circuit and als otriggers increased spontaneus activity in response to a high fat meal, and lesions to it decrease spontaneous activity designed to burn excess calories
• CCK & Leptin released onto arcuate when stomach full or fat cells when filling up -> release MSH on MC4Rs on VMH neuron -> release CRH onto PFC satiety behavior neurons -> increased spontaneous activity
• small amounts of CRH increase spontaneous activity, in large amounts go against and suppress activity
• Ghrelin & low glucose on arcuate nucleus -> NPY release onto LH -> release orexin on PFC hunger behavior neurons -> increased hunger activity (move around to find food)
• orexin knockout eat less & move WAY less
• mutations in either of these pathways often produce severe decreases in physical activity & increase the propensity to develop obesity in mice and may in humans too
• feed a high fat meal, body designed to move more
• eat more than the pathway can handle
• obese people perhaps don't have as effective a pathway

Hypothalamic Nuclei

SCN

MPO

• suprachiasmatic nucleus - receives input about light and circadian cues and increases physical activity during daylight hours
• median pre-optic area - receives input about body temperature and hydration and inversely affects physical activity

nigrostriatal pathway

mesolimbic pathway

mesocortical pathway

• nigrostriatal pathway - critical for activating voluntary movement & inhibiting involuntary movement through its connection to the striatum in basal ganglia
• substantia nigra -> striatum
• genetic defects result in greatly decreased voluntary movement and increas in involuntary movement (parkinson's)
• excessive DA signaling through pathway thought to contribute to hyperactivity in activity-based anorexia (ABA) which is weight loss caused by excessive exercise
• mesolimbic pathway - critical for anticipation of rward and pleasure through is release of DA into neruons in nucleus accumbens
• VTA -> NAc
• NAc lesions derease lcomotor activity especially in response to rewarding cues
• rats bred to be highly active have elevated DA levels but reduced DA receptor levels in NAc
• genetic variation in D1 and D2 receptors are associated with differences in human physical activity
• chronic exercise increase activation of NAc and DA synthesis in VTA - VTA producing more DA but NAc not responding
• overweight women show decreased activation of the NAc when shown pictures of exercise than lean women
• mesocortical tract - connects DA reward pathway with prefrontal cortex
• VTA -> prefrontal cortex
• D4 7R gener variation associated iwth lower mesocortical DA signaling, greate physical activity, greater migratory behavior in hunter gatherer populations, and greatre risk of hyperactivity/ADHD

• amygdala is part oft eh limbic sstem that regulates negative emotional responses to fearful or unpleasant internal or external stimuli
• unpleasant or harmful stimuli are determined by sensory input as well as cognitive input from the insular cortex (decides on internal states)
• these are sent via amygdala to the hypothalamus which in turn stimualtes the symapthetic nervous system and producs avoidance behaviors - fight to flight
• exercise may increase insula/amygdala activation if it is unpleasant or painful such as it is for sedentary or inexperienced exercisers
• overweight women show greate activation of insula when shown pictures of exercise than lean women

• men are more physically active than women
• probably a cultural or environmental component to this, but also possibly biological
• estrogen inversely and testosterone directly associated with physical activity (in obese Latina women)

• angiotensin converting enzyme (ACE) is an enzyme that ctivates angiotensin and increases blood pressure (blood pressure increases during exercises)
• two version of ACE gene - I and D allele
• I allele associated with lower ACE and lower blood pressure and greater endurance exercise performance and greater adherence to an endurance training program (not uncomfortable, stick with it for longer)
• ACTN3 receptor allele are associated with greater performance in power sports like weight lifting and sprinting but have not yet been tied to adherence in those sports

• people are inherently motivated to meet certain fundamental or innate psychological needs
• relatedness - feeling of connection to others
• competence - a feeling of functioning effectively
• autonomy - the feeling of being the causal agent in one's life
• pyramid/continuum of motivation (amotivation -> extrinsic -> intrinsic)
• person's motivation to perform aparticular behavior and whether it is intrinsic vs extrinsic is dependent upon the three basic needs of SDT
• behaviors that increase feelings of competency, autonomy, and relatedness will increase intrinsic motivation to carry out behavior
• behaviors that result in high levels of intrinsic motivation are associated with high likelihood carrying out that behavior in the future
• most research suggests that intrinsic motivation better correlated with exercise adherence than less intrinsic forms of motivation
• in cross-sectional, high levels of intrinsic motivation associatd with greater physical activity but not so much with the other components (relatedness not at all)
• most studies that target intrinsic motivation have found significant improvements in physical activity outcomes
• theory that accounts for most variation in exercise behavior in studies of adolescents

• intentions, whether or not we feel we will do something, are the best predictor of behavior
• attitudes - a person's postive or negative thoughts and emotions concerning the performance of the behavior
• the subjective norm - the degree to which a person feels social pressure to perform a behavior
• so if we believe that exercise is beneficial and that others think we shoul dexercise, our intention to exercise will be strong and we will be more likely to exercise
• attitudes + subjective norm = intentions -> behavior
• originally developed to predict voting behavior

• intentions predict behavior but perceived behavioral control is important too, particularly for less distinct events
• perceived behavioral control - person's perception of their ability to successfully perform a particular behavior
• perceived behavioral control affects intentions, which influence the likelihood of behavior & can also directly influence behavior
• cross-sectional studies show that intentions have the greatest association with behavior (but it's not perfect, only half), and attitudes & perceived behavioral control have the have the highest association with intention
• interventions have had mixed results but none have shown long-term benefits >12 weeks
• interventions try to improve exercise attitudes, reinforce subjective norm, increase perceived behavioral control
• use past performance accomplishments, give vicarious experiences, do social persuasion, educate on what to expect physiologically and affective/emotional states, increase actual control (make schedule, buy jogging stroller if have children)

• social cognition - human behavior is influenced by both cognitive variables (expectations, intentions, beliefs, attitudes) and social forces, pressures, influences and experiences
• behavior determined by:
• personal (cognition) factors - intentions, beliefs, attitudes, sills, thoughts, feelings, etc
• environmental (social) stimuli - expectations, experiences, interactions, commitments, influence,  of others
• self-efficacy - the extent to which an individual feels they will be successful in performing a desired behavior (task specific) ~ basically the same as perceived behavior control
• if someone has the requisite skills and sufficient motivation, then the major dterminant of their performance is their level of self-efficacy
• self-efficacy is most influential on challenging behaviors
• self-efficacy best predicts initiation of a program of regular physical activity and is less predictive of adherence to an exercise program
• self-efficacy in one's ability to carry out a running training program might also be predictive of ability to carry out a biking training program but not a weight lifting program
• self-efficacy influences by past performance/accomplishments, vicarious experiences, social persuasion, physiological and affective/emotional states
• self-efficacy predicts exercise behavior and participation inregular exercise can increase self-efficacy
• interventions that target self-efficacy tend to show improvements but stil some debate as whether this is due to changes in self-efficacy or some other variable 

• behavioral change is not rapid but this is a gradual and cyclic process that progresses through a series of stages
• precontemplation - people have no intention to start exercising in the future
• contemplation - have the intention of exercising within th enext 6 months
• preparation - intend to start exercising in immediate future, starting to exercise but not yet to recommended levels
• action - people are exercising at the recommended levels for health and fitness
• maintenance - people have been exercising at recommended levels for 6 months or more (arbitrary time limit)
• most people report being in maintenance but most research suggests that most peopl eare probably in contemplation
• move into next stage by changing decisional balance (weigh pros and cons)
• change decisional balance by changing how people think about exercise, how people think about themselves, changing aspects of the environment that influence exercise behavior
• people in maintenance stage tend to be higher in self-efficacy and intrinsic motivation
• can predict whether people will progress, regress, or not move but difficulty predicting which specific stage they'll move to
• intervention studies have not been particularly successful in either changing stage progression or in changing physical activity behavior
• many people may not exhibit a stable and orderly progression through the stages

• instrumental support - providing tangible practical assistance to achieve one's goals
• emotional support - expression of encouragement, caring, empathy, or concern
• informational support - giving directions, advice, or suggestions
• companionship support - the availability of people
• validation - confirming thoughts, feelings, problems, or progress of others
• cross-situational studies demonstrated a correlation between amount of perceived social support and the level of physical activity
• in order for it to be beneficial, the social support desired has to match the support given
• if it is too unconditional, it may decrease intrinsic motivation and self-determinaton

• threats, pressure, or other influence a person feels from society or other people to think, feel, or behave a certain way
• coercion - forcing another to behave in an involuntary manner by use of threats or intimidation or some other form of harm - can be financial!
• ridicule and humiliation - to make fun of the appearance or actions of another
• conformity & peer pressure - the influence exerted by a peer group in encouraging a person to change their attitudes, values, or behavior in order to conform to group norms
• criticism - the practice of negatively judging the merits and faults of a person's thoughts, feelings, beliefs, or behaviors
• social pressure can decrease self-esteem or intrinsic motivation (by decreasing feelings of autonomy) which decreases our likelihood to exercise
• can sometimes serve as a source of inspiration and change someone from amotivational to extrinsically motivated
• social pressure shows us the subjective norm is exercise it can increase our intentions to exercise; also can increase our self-efficacy through social persuasion which increases our intentions to exercise

sources of social support

+ social facilitation

+ competition

• spousal/partner support - dropout rates lower for those that do a program with partner, active people likely to have active partner
• parental/familial - may be single most important variable in determining physical activity of children, and perceived parental support another big variable with two supportive parents to have a stronger influence
• physician - don't give physical activity counseling but when they do most amenable to changewith them
• co-exercisers & strangers - do more activity when other people are around and watching
• social facilitation - tendency for people to do better on simple tasks when in the presence of other people
• competition - desire to do better than someone else at a particular task

• technology has decreased amount of occupational physical activity since stone age
• technology has decreased time & energy spent in household physical activity
• technology takes up the overwhelming amount of our daily free time
• children spend more time in screen time & multitasking, but media use does not predict physical activity levels
• time spent watching TV is small but significant predictor of BMi and being overweight in childhood
• TV viewing associated with poorer dietary patterns (commercials advertising bad food & snacking poorly)

• internet-based interventions demonstrate small & short-lived but statistically significant increases in physical activity or positive health changes related to physical activity in children 
• prompting & reminder to be active, also logging
• PROS cheap, more participants, easier, Americans have access, fits in schedules
• CONS questions more challenging to answer, not everyone has access & these people are also less active, less effective than face to face
• social media-based intervention has shown no increase in physical activity compared to control; use of facebook is inversely associated with physical activity levels in college students
• PROS social support, psyhological foundation, subjective norms, inexperiensive, large population
• CONS not everyone participates, could correlate with specific population, likes probably not enough
• cell phone & smart phone allow exercises to work out and small & growing number use them for health purposes
• cell/smart phone interventions can produce moderate improvements in physical activity (prompting again)
• PROS untether from desks & offices so more time to be active, easy & inexpensive for large subjects, many apps provide info with greatre info about activity, goals, make into a game
• CONS cell phone usage while working out decreases attention &  increases risk of injury & can interfere with workout
• active gaming shows no major gains in health or fitness outcomes & amount of use over time typicall decreases dramatically as kids get bored or distracted
• PROS can make physical activity fun, increase phyisical activity compared to non active game & other sedentary behaviors, allows outlet for self-conscious, insecure, anxious; may be more beneficial for improving strength, coordination, flexibility, functional gains, fitness in health-comprised patients and the elderly
• CONS inrease in energy very slow & no major gains in health or fitness, ay prevents kids from real activity - particularly outside

• commuting by car decreases physical activity
• food preparation time goes down too, so getting fast food
• longer commutes associated with hypertension, greater risk of CVD, chronic disease, greater BMI, weight gain, greater stress hormone secretion, negative mood, sickenss, decreasesd social contact, greater likelihood of divorce, decreased life satisfaction
• people tend to over-value the material fruits of their commute (money, house size) & undervalue what they've given up (free time, social interaction)

• make walking safer
• increase biking and walking! (Smeed/Jacobsen's Law)
• make walking more interesting
• make walking more useful
• make walking more comfortable

• complete streets - streets that are designed to be safe and efficient for all users, including pedestrians, bicyclists, motorists, and transit riders
• road diet - decreasing the number of dedicated auto lanes on a street to increase the space dedicated to other forms of transportation if possible without decreasing traffic flow excessively

• addictive behaviors increase dopamine release by neurons in the VTa of midbrain onto neurons of NAc which is associated with pleasure and reward
• repeated exposure to pleasurable stimuli can increase DA release but decrease DA receptor level which is thought to underlie the phenomenon of tolerance - decrease DA sensitivity
• exercise can be used as a substitute addiction except for in the case of alcoholism where drink alcohol more & exercise more
• DA synthesis enzymes increased and DA receptor levels decreased by exercise also this is seen in mice bred for wheel running
• rats display conditioned place preference to wheel running & aggression when the wheel is locked
• dopamine agonists or antagonists in the nucleus accumbens decreases wheel running activity
• inactivation of endocannabinoid receptor on GABA neurons of the VTA decreases wheel running but not other voluntary movement behaviors
• signs: exercise way too frequence, intereferes with life and goals, continue despite injuries, have no joy or sense of accomplishment
• addiction result in body image disturbances (when think body reality is worse than body ideal), increased injuries, osteoporosis (women, more likely), excessive weight loss (which cancause hormonal disruptions), amenorrhea in females (no more menstruating), heart arrhythmias