Sitting, Sunlight and Red Light

Truly the light is sweet, and a pleasant thing it is for the eyes to behold the sun. — Ecclesiastes 11:7

Every chapter so far has been about something we let in: a chemical in the water, a metal in a filling, an oil in the pantry, a signal in the air. This chapter is about two things we have let go. Movement and sunlight. Nobody sold them to us in a plastic bottle, and nobody took them away by force. We simply walked indoors, sat down and forgot to come back out.

That matters for detox more than most people realize. A body that sits all day in artificial light is like a house with the windows painted shut and the back door nailed closed. The trash still comes in. It just has nowhere to go.

My guide for this chapter is Dr. Joseph Mercola, whom you met in the sugar and EMF chapters. For years he has taught that sitting, staying indoors and living under the wrong kind of light are hazards in their own right, and that the cure is free: get up, get outside and let the sun do part of the work.

The Indoor Life

Dr. Mercola puts the change in two numbers. For most of history, people spent around ten hours a day outdoors, farming, herding, walking to market, washing clothes at the river. Today, he says, most of us spend less than thirty minutes outside. The rest of the day we are under a roof, usually in a chair, usually under LED lights.

Think of it as a toxin of omission. Nothing harmful has been added, but two things the body counts on every day have quietly been removed:

• Movement, which pumps the lymph, works the muscles that clear sugar and fat from the blood, and makes us sweat.
• Light, the full spectrum of the sun, which the body uses to make vitamin D, nitric oxide and melatonin, and to set its clock.

Lose both, and every other chapter in this book gets harder. The exits you will meet in Chapter 12 slow down. The metals of Chapter 4 linger. The good news is that this is the cheapest chapter to put into practice. You already own a pair of feet and a front door.

The Chair

Here is the part that surprises people: exercise does not undo sitting. Dr. Mercola is blunt about it. You can run in the morning and still carry the risks of sitting for the next nine hours. An hour at the gym does not cancel a day in a chair, any more than a salad cancels a box of doughnuts.

Much of what he teaches on this comes from Dr. Joan Vernikos, the former director of NASA's Life Sciences Division, who studied what weightlessness does to astronauts. Their bones thinned, their muscles wasted, their blood sugar and balance went wrong, and they aged fast. Then she noticed that people who sit all day on earth show the same changes, only more slowly. Her book on it has a title you won't forget: Sitting Kills, Moving Heals.

What she found was that the body needs to fight gravity, and it needs to do it often. In NASA's bed-rest studies, standing up protected the volunteers better than the same amount of time spent walking on a treadmill. The key was not how hard they moved but how often they changed position against gravity.

The numbers to remember:

• Stand up often. Dr. Vernikos recommends getting up from a chair about 32 to 36 times a day. Dr. Mercola's bare minimum is to break up your sitting every 20 to 30 minutes.
• Sit less in total. Dr. Mercola aims for less than three hours of sitting a day (he aims for less than one himself).
• Walk. His goal is around 10,000 steps a day, on top of any exercise.

Getting up does not need to be a production. Stand to take a phone call. Walk to refill your water instead of keeping a jug at your desk. Do a few squats while the kettle boils. Put the printer across the room on purpose. Dr. Mercola points out that blood fats start to rise within about thirty minutes of sitting still, so the small interruptions matter more than the big workout.

And there is a detox reason, too. The lymph, the body's drainage system, has no heart to pump it. It moves when your muscles squeeze and your lungs breathe. A body that sits all day is a body whose drains are barely moving.

What Sunlight Does

For a generation we have been taught to treat the sun as an enemy, something to block, avoid and apologize for. Dr. Mercola teaches nearly the opposite: sunlight is a nutrient, and we are starving for it.

Sunlight is not one thing. It is a whole spectrum, and different parts of it do different jobs:

• UVB makes vitamin D in the skin. Vitamin D runs hundreds of genes, including many in the immune system. Dr. Mercola goes further: he says the vitamin D level in your blood is best understood as a marker of how much sun you get, and that sunlight does far more than a vitamin D pill can.
• UVA releases nitric oxide from the skin into the blood. Nitric oxide relaxes the blood vessels, which is one reason sun exposure is linked to lower blood pressure.
• Near-infrared light, which makes up about half of sunlight's energy, goes deep. It passes through skin, light clothing and even bone. Dr. Mercola, drawing on the work of melatonin researcher Dr. Russel Reiter, teaches that near-infrared light prompts the mitochondria, the power plants in every cell, to make their own melatonin. In his words, about 95 percent of the body's melatonin is made in the mitochondria, not in the brain. There it works as the cell's own antioxidant, mopping up the oxidative damage you met in Chapter 1 and Chapter 9.
• Bright morning light sets the body clock. Light in your eyes early in the day tells the brain it is morning, which is how you get sleepy at the right time at night.

Sunshine through a window still counts. Sitting in a sunny window is healing in its own right: the light sets your body clock, lifts your mood and warms you, and ordinary glass lets some of the near-infrared through. It is not as good as going outside, because window glass blocks the UVB that makes vitamin D, and modern energy-saving glass reflects much of the near-infrared. So on the days you can't get out, sit by the window, open it when the weather allows, and go outside when you can.

Light bulbs are a different story. LED and fluorescent lights have no near-infrared at all and are heavy in blue light. During the day, that is a poor substitute for the sun. After sunset, it is worse: blue light in the evening tells the brain it is still noon and holds back the melatonin you need for sleep.

Put it together and the indoor life looks like this: no near-infrared to protect the cells, too little UVB for vitamin D, too little UVA for the blood vessels, too little light in the morning and too much in the evening. All of it, Dr. Mercola teaches, is fixed by the same thing: going outside.

Sunlight and Seed Oils

If the sun is so good for us, why do so many people burn? Dr. Mercola's answer brings us straight back to Chapter 6.

He teaches that the linoleic acid from seed oils is stored in the fat of the skin. Linoleic acid is fragile. When ultraviolet light hits it, it oxidizes and sets off the inflammation we call a sunburn. In his view, a skin built from soybean, corn and canola oil burns easily, and a skin built from butter, tallow and olive oil holds up far better. The sun didn't change. The skin did.

That shapes his advice on how to get your sun:

• Clear the seed oils first. Until you have been off seed oils for a good while, avoid the strong midday sun. Dr. Mercola gives different time frames in different articles, from three months to six months, and says the oils stored in the body's fat take a year or more to fully clear. Until then, take your sun in the morning and late afternoon, when it is gentler.
• Then build up. Once the oils are out, he recommends working up to about an hour of sun a day around solar noon, with as much skin showing as is decent, a little longer each day.
• Never burn. Pinkness is your signal to cover up or go inside. A burn is damage, not a tan in progress.
• Use shade and clothing before chemicals. Dr. Mercola avoids conventional sunscreens, which block the UVB that makes vitamin D and put the same kind of chemicals on the skin you read about in Chapter 3. When you need protection, a hat, a shirt and a tree work without a single ingredient list. If you must use a sunscreen, choose a mineral one made with zinc oxide.

Red and Near-Infrared Light

The sun is the original red light therapy. Today you can also buy it in a panel, and Dr. Mercola has taught about it for years, interviewing researchers such as Dr. Michael Hamblin, then at Harvard's Wellman Center for Photomedicine. The scientific name is photobiomodulation: using red and near-infrared light to change what cells do.

The idea is simple. Inside the mitochondria is an enzyme called cytochrome c oxidase, the last step in the chain that makes the cell's energy, ATP. Red and near-infrared light are absorbed by that enzyme and help it run, so the cell makes more energy and handles stress better. Dr. Mercola describes the different colors as reaching different depths:

• Red light, around 660 nanometers, works near the surface: the skin, collagen and wound healing.
• Near-infrared, around 850 nanometers, goes deeper, into muscles, joints and organs.

His most important point about dose: more is not better. Light therapy follows what he calls a Goldilocks curve. A little helps, the right amount helps most, and too much turns the benefit off again. For a large panel he suggests sessions of about ten minutes on the front and ten on the back, not an hour.

A panel is a nice addition, not a requirement. The sun is free, it has the whole spectrum, and it comes with fresh air. A near-infrared sauna, which you will meet in Chapter 12, gives you light and sweat at the same time.

Exercise: Enough, Not Extreme

Dr. Mercola's teaching on exercise has changed over the years. He now says exercise has a sweet spot, and that more is not always better.

• Walk the most. Walking is, in his words, the exercise humans were designed to do. He recommends 7,000 to 12,000 steps a day, working up to about an hour of walking daily, and he says walking has no known upper limit of harm.
• Keep hard training short. He recommends keeping high-intensity exercise to under about 75 minutes a week. Past that, he says, the benefits level off, and very high volumes of endurance training strain the heart.
• Build some strength. Two strength sessions a week of 20 to 40 minutes are enough. For older people or anyone with sore joints, he favors blood flow restriction training (KAATSU), which uses light weights with special bands so the muscles get the benefit of heavy lifting without the strain.

If you have been sitting for years, that first number is the only one that matters right now. Walk. Walk after meals, walk while you talk on the phone, walk the dog even if you don't have one.

Moving Toxins Out

Here is where this chapter earns its place in a detox book. Movement and sun are not only about fitness. They open three of the body's exits.

• Sweat. Dr. Mercola calls the skin a second elimination organ. He points to studies in which people's sweat carried out heavy metals such as lead, cadmium, arsenic and nickel, the same metals from Chapter 4, and in which sweat from exercise carried more of some metals than sweat from a sauna. His advice is a few good sweats a week, from a brisk walk on a warm day, real work in the garden, exercise or a sauna, with plenty of water and minerals to replace what you lose. Shower afterward so what came out doesn't sit on the skin.
• Lymph. As you read above, the lymph moves only when you do. Walking is the main pump. Bouncing on a small trampoline (rebounding), dancing and deep breathing all help. Chapter 12 shows a short routine for getting the lymph moving.
• Bowel and blood sugar. Walking after a meal moves the bowel along and helps the muscles take up sugar from the blood. The longer food and waste sit still, the more of what you are trying to clear gets reabsorbed.

There is a fourth benefit that is easy to miss: sleep. The brain does much of its own cleaning at night, and you sleep deeper after a day with real light in the morning, real dark in the evening and real tiredness in the legs.

Outdoors: Sun, Ground and Green

The best way to put this whole chapter into practice is to do it all at once: move outside, in the sun, with your feet on the ground.

In Chapter 9 you met grounding, or earthing: direct skin contact with the earth. Dr. Mercola teaches that the earth's surface carries free electrons that act as antioxidants, and that grounding lowers inflammation and stress. He recommends 30 to 40 minutes a day barefoot on grass, sand, soil or bare concrete, or standing in the ocean. Rubber-soled shoes block the connection; leather soles do not.

Put the pieces together and a single daily walk outdoors does what no supplement can: it breaks up sitting, works the muscles, moves the lymph, makes you sweat, sets your clock, gives you UVB, UVA and near-infrared light, and, if you slip off your shoes for part of it, grounds you. It is the most complete detox therapy in this book, and it costs nothing.

The Other Side of the Debate

As with every chapter, you should know where mainstream medicine disagrees, so you can weigh it with the tests from Chapter 1.

• Sun and sunscreen. The American Academy of Dermatology holds that there is no safe level of unprotected sun exposure for the sake of vitamin D. It recommends getting vitamin D from food and supplements and using sunscreen, shade and clothing. Dr. Mercola points to studies of outdoor workers who did not have more melanoma than indoor workers, and argues that it is burning, not regular sun, that does the harm.
• Seed oils and sunburn. Mainstream skin science explains sunburn as ultraviolet damage to the DNA in skin cells and gives diet little role. The link Dr. Mercola teaches between linoleic acid and burning comes from the chemistry of how that fat oxidizes, and from many people's experience after cutting seed oils; it has not been tested in large trials.
• Mitochondrial melatonin. That near-infrared light makes the mitochondria produce melatonin is Dr. Reiter's hypothesis, and he says himself that it has not yet been proven.
• How much toxin leaves in sweat. Toxicologists agree that metals do come out in sweat but say the amounts are small compared with what the liver and kidneys clear. That is one more reason to open all the exits, not only one.
• How much exercise is too much. Some large studies have found that people who do two to four times the recommended vigorous exercise live as long as, or longer than, those who do less. Dr. Mercola reads the heart-rhythm studies the other way. On walking and sitting less, everyone agrees.

Get Up and Get Out, in Order of Impact

You don't need a gym membership, a light panel or a trip to the beach. Start at the top of this list and work down:

1. Break up your sitting. Stand up every 20 to 30 minutes, all day. Set a timer if you need one.
2. Walk every day, outside if you can. Start where you are, even ten minutes after each meal, and build toward an hour.
3. Get morning light. Go outside for ten minutes within an hour of waking, without sunglasses, and without looking at the sun.
4. Dim the evening. After sunset, use warm, low lamps instead of bright overhead LEDs, and put screens away before bed.
5. Clear the seed oils, then build your sun. Morning and late-afternoon sun first; after several months off seed oils, work toward an hour around midday. Never burn.
6. Ground yourself. Bare feet on grass, sand or soil, ideally during your walk.
7. Sweat a few times a week, with water and minerals, and shower afterward.
8. Add red light if you like, short sessions, eyes protected.

Plain safety facts. Some medicines and herbs make the skin burn much faster in the sun, among them doxycycline and other tetracycline antibiotics, some diuretics, isotretinoin and other retinoids, and St. John's wort. Anyone taking them goes slowly and covers up. Anyone who has had skin cancer works out their sun plan with their dermatologist. Never look straight at the sun, and protect your eyes from bright red-light panels. Anyone who has been inactive for a long time, or who has heart disease, starts with short, easy walks and builds up gradually. Drink water before and after you sweat, and leave the heat if you feel dizzy or sick.

The Creator made us to live in a garden, not a cubicle. We work under the sun, rest in the dark and walk on the ground. Give your body a little more of that each day, and it will do a remarkable amount of its own cleaning.

Footnotes and sources for this chapter

Sources and Further Reading

• Mercola, J. Articles on the dangers of prolonged sitting. Mercola.com, 2014 and 2026.
• Mercola, J. Interview with Dr. Joan Vernikos on low-intensity, high-frequency movement. Mercola.com, 2017; reprinted on his Substack, Take Control of Your Health, 2024.
• Vernikos, J. Sitting Kills, Moving Heals: How Everyday Movement Will Prevent Pain, Illness, and Early Death, and Exercise Alone Won't. Quill Driver Books, 2011.
• Mercola, J. “Is Sunbathing More Important Than Vitamin D?” (melatonin in the mitochondria), Substack, 2022; and “What You Need to Know About Melatonin,” interview with Dr. Russel Reiter, 2022.
• Zimmerman, S., and Reiter, R. J. “Melatonin and the Optics of the Human Body.” Melatonin Research 2, no. 1 (2019): 138–160.
• Mercola, J. Articles on sun exposure and cellular health (2024) and natural detox (2026), Substack; and “The Fast-Track Path to Clearing Vegetable Oils from Your Skin,” Substack, 2025.
• Mercola, J. Articles on light, mitochondria and circadian rhythms (2025) and on the health risks of LED lighting (2023). Mercola.com.
• Mercola, J. Article on the wavelengths of light used in photobiomodulation, Mercola.com, 2025; and his interview with Dr. Michael Hamblin on photobiomodulation.
• Hamblin, M. R. “Mechanisms and Applications of the Anti-Inflammatory Effects of Photobiomodulation.” AIMS Biophysics 4, no. 3 (2017): 337–361.
• Mercola, J. Article on vigorous exercise, Substack, 2026; and his interview with Dr. James O'Keefe on the sweet spot for exercise volume, 2023.
• Mercola, J. Article on sweating out heavy metals, Substack, 2025; and his interview with Dr. Perry Nickelston on the lymphatic system, Mercola.com, 2025.
• Sears, M. E., Kerr, K. J., and Bray, R. I. “Arsenic, Cadmium, Lead, and Mercury in Sweat: A Systematic Review.” Journal of Environmental and Public Health, 2012.
• Mercola, J. Article on the effects of grounding. Mercola.com, 2015.
• American Academy of Dermatology. Position statement on vitamin D.
• Dr. Joe Mercola: Sun, Sauna, Sleep & Seed Oils, Wake Up Podcast with Aleksandar Svetski, 2022 (the video for this chapter's Lesson).