With the start of fall comes the start of cold and flu season. We’re spending more time indoors, there’s less sunlight, and changing routines can challenge the immune system.
While many people turn to supplements, lifestyle choices are equally powerful in shaping how the body defends itself. Physical exercise, quality sleep, social connection and more play an important role in lowering infection risk and boosting immune resilience.
The Science of Lifestyle and Immunity
The immune system works best when it’s in balance. When it’s too weak, you become vulnerable to infections. If it’s too strong, you run the risk of chronic inflammation or developing autoimmunity, when the body mistakes healthy cells for harmful ones.
Our lifestyle can influence immunity through:
- Exercise: regular, moderately strenuous activity boosts immune surveillance and strengthens the body’s defenses through stimulating immune cells like natural killer cells (NK), and T-cells.
- Stress management: Chronic stress triggers the endocrine (hormone) system which releases stress hormones in the brain and neurotransmitters that affect immune function.
- Time in nature: Spending time in nature and green spaces has been linked to a variety of health benefits including boosting immunity through decreasing stress. Community and connection: Creating bonds and social connection reduces stress and boosts immune responses by improved antibody production and increasing anti-inflammatory markers.
- Sleep: Getting enough, high-quality sleep is crucial for immune restoration, when the body can produce key proteins and cells to fight off infection. Chronic sleep deprivation is linked to increased risk of infection and chronic conditions like cardiovascular and metabolic disease.
Physical Activity: Moving the Body to Prime Immunity
There are several key benefits to moderate exercise on our immune system. It improves circulation, allowing immune cells like natural killer cells and T-cells) to detect and fight pathogens more efficiently. Inflammation is lowered through reducing systemic pro-inflammatory cytokines. Movement and exercise also helps to regulate stress hormones like cortisol, which contributes to inflammation, and supports better sleep.
Research suggests that regular physical activity can help prevent many diseases linked to immune system activation. This is connected to increased muscle tone, cardiorespiratory and metabolic health, sleep and cognition which impact inflammation and anti-inflammatory cytokines. These keep the body in an anti-inflammatory status, a key factor in maintaining health and reducing chronic disease.
How to boost activity this fall:
- Take brisk daily walks in cool weather
- Jump on a bike for a long ride on weekends
- Do yoga or Pilates indoors on rainy days
- Strength training with body weight or light weights
Time in Nature: The Outdoors as an Immune Ally
Nature has a greater effect on us than many realize. The shift to many people in urban and developed areas and spending more time indoors may be affecting our health.
Spending time in nature has been linked to:
- Lowering stress and anxiety.
- Boosting vitamin D when in the sun.
- Exposes you to diverse microbes that support immune tolerance.
- Phytoncides, for example, are plant-derived compounds that we are naturally exposed to when outdoors. They’ve been shown to increase NK cell activity, helping fight infections and abnormal cells.
Forest bathing studies in Japan demonstrate measurable changes in immune markers lasting up 30 days after a nature immersion. Called “Shinrinyoku” in Japanese, these trips involve short leisurely walks through a forest or other wooded area. Research found significantly increased levels of natural killer cells and significantly lower concentrations of adrenaline in forest bathing days compared to controls. This suggests that spending time in nature has the power to boost immune function and protect us from illness and infection.
Implementing nature into you fall activities:
- Take weekend hikes to enjoy fall foliage.
- Try “green exercise” like walking, jogging, or yoga in a park.
- Rake leaves or garden as outdoor chores with added immune benefits.
- If you don’t live near a forest, find a city park or bench near some trees and sit with book.
Community and Connection: Social Health as Immune Health
Humans are social creatures. We need community and social interaction to survive. Chronic loneliness and social isolation are linked to higher levels of inflammation and weaker antiviral and immune responses.
Social connection is a powerful stress buffer. Strong relationships help lower stress hormone levels, while emotional support builds bonds that ease the mental load we carry throughout our day. Being part of a community also encourages healthier habits from sharing regular meals to staying active together, creating a ripple effect that benefits both mind and body.
Research suggests that feeling socially safe and connected can turn down the stress response and inflammatory gene expression. This likely comes from oxytocin, the “connection hormone” that is released during social bonding. It’s linked to lowering stress hormone, directly regulating immune cells, and reducing inflammation.
How build connection this fall:
- Join a community walking or fitness group.
- Host potluck dinners with nourishing, seasonal foods.
- Volunteer for local organizations.
- Make family walks or game nights part of weekly traditions.
Mindfulness and Stress Management: Calming the Immune System
Chronic stress raises cortisol, which suppresses immune function and increases inflammation. Mindfulness and meditation practices have been used for centuries as a way to enhance health and well-being.
Research looked at immune parameters such as stimulating inflammatory proteins, gene expression and cellular transcription, quantity of immune cells, immune cell aging, and antibody response. Results suggest that meditation and stress management are associated with changes in immune processes such as inflammation, immunity, and biological aging improving overall function.
Mind-body practices to try:
- Meditation or guided breathing for 5–10 minutes daily.
- Yoga or tai chi to combine movement and mindfulness.
- Gratitude journaling, mindfulness practice, or prayer to shift focus toward positives.
- Use earlier sunsets as a cue to wind down with calming practices instead of late-night screen time.
Quality Sleep: Restoring the Immune System
Sleep is crucial for all our bodily functions. Inadequate or poor-quality sleep weakens immune defense and increases inflammation. Even one night of poor sleep can reduce natural killer cell activity putting us at risk for infection and sickness.
Studies show that the brain and sleep and the immune system are constantly communicating through shared signals (neurotransmitters, hormones, and cytokines) and the direct nerve connection. Many immune processes follow a daily circadian rhythm that closely follows our sleep-wake cycle. Not getting enough sleep can disrupt these processes negatively impacting how our immune system works.
Strategies for getting quality sleep:
- 7–9 hours per night is critical for immune memory and antibody production.
- Keep a consistent bedtime and wake-up schedule, even on weekends.
- Create a sleep-friendly environment; cool, dark, and quiet.
- Limit caffeine and alcohol in the afternoon and evening.
- Create a wind-down routine, like reading, gentle stretching, or herbal tea.
- Use the season’s longer nights as a natural reminder to shift to earlier bedtimes, aligning your sleep cycle with the rhythm of the season.
Putting It All Together: Your Fall Immunity Plan
This fall, remember the key pillars of strong immunity: movement, time in nature, meaningful connection, mindfulness, and quality sleep. You don’t need to overhaul your life all at once, start small by focusing on one area each week.
With each step, you’ll not only strengthen your immune defenses but also nurture resilience and overall wellbeing, helping you thrive through the season ahead.