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Light and Exercise
Dr. Dawn-Elise Snipes PhD, LPC-MHSP, LMHC
Executive Director, AllCEUs
~ Learn about light, light therapy and circadian rhythms
~ Define exercise
~ Highlight the benefits of exercise: Emotional, Mental, Physical and Social.
~ Review points about exercise that every person should know
~ Explore how exercise can be incorporated into a daily routine

~ Circadian rhythms must be synchronized on a regular basis
~ Suprachiasmatic (supra-ki-asmatic) nucleus (SCN) of the hypothalamus as the central circadian pacemaker
~ The SCN receives direct input from the retina
~ This is reinforced through downstream neural (thinking), neuroendocrine (stress), and autonomic (breathing/heart rate/temperature) outputs. (social training)
~ Normal sunlight has the benefit of setting circadian rhythms as well as helping the body produce Vitamin D which makes neurotransmitters more bioavailable.

~ Daily interactions between the hypothalamic and the (SCN) regulate:
~ Body temperature
~ Cortisol, sex hormone, serotonin, melatonin levels
~ Feeding rhythms, energy expenditure, thermogenesis, and active and basal metabolism.
~ Intensity (>200lux/<12 Lux) and wavelength (temperature (>6000 kelvin/<2000 kelvin)) of a light stimulus has an important influence on the direction and magnitude of response as does timing. ~ We are most sensitive to light during the night and far less sensitive to light in the middle of the day (matinee) ~ When exposed to light in the late day (7-9pm), it produces a phase delay shift (up to 3h) ~ Light exposure in the early morning (3-5am) produces advance shifts (~2h) Light Light ~ Groups exposed to light greater than room light level showed a significant phase advance shift ~ Groups exposed to darkness or dim light (the 12 lux group) for the same 3-cycle 5-hour stimulus timing drifted to a later phase ~ Researchers tested 13 5.3-minute light stimuli interspersed with 19.7-minute episodes of darkness against extended light exposure for 5 hours. ~ The intermittent light group received 63% of the light duration showed phase shifts that were not significantly different from the continuous bright light group (Hope for NICU workers) Light ~ Melatonin was suppressed within 5 minutes of the start of each light stimulus ~ Melatonin levels began to increase within 10 minutes after each light pulse was ended ~ Lack of melatonin can lead to insulin resistance ~ Results indicate that melatonin might prevent obesity through its effect on adipocytes and/or by affecting thyroid hormones ~ Lack of daytime light exposure within buildings or increased exposure to artificial light (or moonlight) at night is one of the causes of insufficient sleep, or so-called social jet-lag Light and Mood ~ Seasonal fluctuations in mood thought to be associated with the intensity and duration of sunlight have been observed in many bipolar patients. ~ Shifts to the depressive phase have been observed to begin in autumn as day length decreases and often persist throughout the winter ~ By march, when day length increases, manic episodes become more prevalent, a phenomenon nicknamed “march madness” ~ Seasonal Affective Disorder is also thought to impact hundreds of thousands of people each year. Light ~ Effects of constant light exposure ~ Increased body weight/food intake ~ Insulin resistance ~ Increased fat accumulation ~ Increased accumulation of cholesterol, triglycerides and fatty acids in the liver ~ Learning deficits ~ Irritability ~ Effects of insufficient light (think hibernation) ~ Disrupted hunger/satiation hormones ~ Fatigue ~ Depression ~ Impaired sleep quality ~ Reduced basal metabolism Light Interventions ~ LED pre-sleep lights emit very little blue light, encouraging the body to release melatonin, the hormone that tells the brain that it is nighttime and to get ready for a peaceful night's sleep. Nighttime lights 2500K or lower (Preferably 2000K) ~ Blue light filtering software and apps; Drift TV ~ 30 minutes of blue-light (daylight) exposure in the morning led to better working memory performance and faster reaction times (How? 6000K or higher, 120 watt equivalent at the table, sunny window) ~ Reducing daily eating duration to 10–11 h for 16 weeks, without decreasing calories or change nutrition quality, induced weight loss and improved sleep (beginning with breakfast) How Exercise Impacts Recovery ~ A body in motion tends to stay in motion ~ A body at rest tends to stay at rest ~ When you exercise you are causing muscles to tense and relax ~ A muscle cannot be tense and relaxed at the same time ~ Exercise reduces muscle imbalances and chronic pain which can improve sleep ~ Exercise releases serotonin and endorphins which have a calming effect and improve relaxation ~ You cannot be stressed and calm at the same time How Exercise Impacts Recovery ~ Exercise increases breathing and oxygenates the blood ~ Exercise can release cortisol ~ Exercise can cause you to be exposed to the sun more ~ Exercise can put you around other positive people ~ Exercise can be a sensation distraction or cathartic ~ Exercise can improve self esteem and self efficacy through the achievement of regular, small goals What is Exercise ~ Anything that moves the body ~ Gardening ~ Playing with the dog ~ Weight lifting ~ Jogging ~ Focused exercise ~ Pay attention to ensuring balance between the right/left and front/back of the body Exercise Basics—Front and Back ~ Biceps bend the arm ~ Triceps extend the arm ~ Exercises ~ Pushups (against the wall, counter or back of the sofa) ~ Vacuuming ~ Picking up and setting down groceries or children ~ Weeding ~ What else? Exercise Basics—Front and Back ~ Chest & shoulder muscles push arms forward ~ Back & shoulder muscles pull arms toward you ~ Exercises ~ Pushups ~ Pushing or pulling anything (try to use both arms equally when vacuuming) ~ Sit tall and squeeze shoulder blades together Exercise Basics—Front and Back ~ Quadriceps straighten the leg ~ Hamstrings bend the leg ~ Exercises ~ Walking up stairs ~ Picking up and setting down boxes (Bend at the knees, not the hips) ~ Squatting and standing (putting away dishes/groceries) ~ What else?? Exercise Basics—Front and Back ~ Abdominals bring the pelvis and ribcage together ~ Lower back straightens ~ Exercise ~ Standing curl pelvis forward ~ Crunches ~ Bending at the waist and standing up (Exercise caution) ~ Sitting on an exercise ball ~ Note: Tight hamstrings and weak abdominals often cause low back pain Exercise Basics –Left & Right ~ Pertains mainly to core muscles ~ Left and right of the spine ~ Obliques (left and right sides of the abdomen) ~ Left/Right imbalances are most associated with ~ Poor posture ~ Back pain and spasms ~ Interventions ~ Ensure you use both arms equally ~ If you lean to one side, lean to the other (purse, briefcase) ~ Pay attention to posture Summary ~ Light helps set our circadian rhythms which impacts cortisol, serotonin, sex hormone and melatonin levels as well as thyroid hormones, thermogenesis, and insulin. ~ Disruptions in circadian rhythms produces many emotional, cognitive and physical symptoms similar to anxiety and depression ~ Exercise can help improve mood through ~ Pain relief ~ Increased self esteem ~ Increased social support ~ Increased oxygenation ~ Maybe even improved hydration