5 Biggest Mistakes People Make Before Flu Season
ESTIMATED READ TIME: 4-5 MINSThe shift from summer to fall brings a slew of changes for many of us: less sunshine, less movement, disrupted sleep, and more processed foods, especially once the holidays arrive. This way of living might be normalized, yet it leaves us more vulnerable when flu season arrives.
I don't believe preparing for cold and flu season should begin when you feel the first tickle in your throat. The months leading into winter are an opportunity to strengthen your immune defenses and become more resilient against germs; this way, you're better prepared for what's ahead.
That means spending plenty of time outdoors while the weather's still nice, maintaining healthy vitamin D levels, staying active, prioritizing restorative sleep, and choosing foods that nourish rather than deplete you.
Here are five common mistakes I see people make, and what I recommend doing instead…
1. Wasting the Sunniest Months of the Year
Vitamin D is unique because it functions more like a hormone than a typical vitamin. It influences immune function, inflammation, bone health, muscle function, mental health, and more.
Studies show that maintaining a relatively high vitamin D blood level—around 40–50 ng/mL or higher—can help the immune system function optimally and lower the risk of certain infections, sepsis, and some autoimmune conditions.
And one of the best ways to produce vitamin D is completely free: sunshine.
UVB rays from sunlight trigger vitamin D production in your skin. The problem is that as fall progresses and the days become shorter, many people, especially those living in northern climates, get much less UVB exposure.
That's why I like to think about "solar maxing" during summer and early fall: safely taking advantage of the longer, sunnier days while they're available.
Vitamin D is fat-soluble, which means your body can store some of it for later use. So rather than entering winter already deficient, aim to build your reserves and maintain healthy levels throughout the year, especially as you head into flu season.
Whenever possible, spend regular time outdoors with some skin exposed to the sun without burning. If you live somewhere with long winters or have limited sun exposure, ask your healthcare provider about testing your vitamin D level and whether supplementation makes sense (such as in the range of 5,000 and 8,000 IU daily).
Overall, don't wait until January to start thinking about vitamin D. Prepare while the sun is still shining. Supplementing can be useful too. I generally prefer vitamin D3, often alongside vitamin K2 and sufficient magnesium to help with absorption and how your body uses it.
2. Spending Almost All Day Indoors
Life today makes it surprisingly easy to go from your house to your car to your office or school and back home, all without moving much or spending meaningful time outdoors.
While this is convenient, we weren't designed to live that way. Indoor environments can have higher concentrations of certain pollutants, particularly when ventilation is poor.
Research shows there are often two to five times more pollutants in indoor air because everyday sources release gases and particles that get trapped inside homes and buildings.
Time outside, meanwhile, gives you exposure to fresh air, natural light, movement, and nature, all things that can help regulate your circadian rhythm and reduce stress.
Getting outdoors becomes even more important once colder weather arrives and we're tempted to stay inside all day.
Make outdoor time part of your routine even when the temperature drops. Take a walk after lunch. Drink your morning coffee outside. Play with your kids or grandchildren. Walk your dog. Go hiking on the weekend. Open the windows when weather and outdoor air quality permit.
You don't need to spend hours in the wilderness; 20 or 30 minutes outside is enough to get you moving, expose your eyes to natural light, take some deep breaths, and give your nervous system a break.
3. Letting Your Sleep Schedule Fall Apart
The spontaneity of summer can be wonderful, but it can also wreak havoc on our sleep schedules. Longer evenings, vacations, travel, social events, and later bedtimes can gradually shift when we go to sleep and wake up, sometimes leaving us feeling groggy.
Fall is a great time to bring back consistency to our sleep patterns, particularly because we tend to feel sleepier when it starts getting darker outside earlier.
Sleep isn't merely "downtime." While you sleep, your immune system is actively coordinating defenses, regulating inflammation, and producing molecules that are involved in immune responses. Research has even found that people who routinely don't get enough sleep can be more susceptible to viral, bacterial, and parasitic infections, including respiratory infections like the flu.
For most adults, the general recommendation is to get seven to nine hours per night and keep your bedtime and wake time fairly consistent, even on weekends.
Think of fall as an opportunity to reset your internal clock before winter begins with good sleep hygiene, which can include:
Getting outdoor light shortly after waking
Keeping your bedroom cool and dark
Dimming lights as bedtime approaches
Putting phones and other screens away before bed
Avoiding heavy meals and excess alcohol late at night
Creating a calming nighttime routine that might include prayer, gratitude, Scripture, reading, or simply spending a few quiet minutes with your family.
4. Moving Less as the Weather Gets Colder
When it's warm and sunny, movement tends to happen more naturally, such as when gardening, swimming, walking outside, working outdoors, taking vacations, and playing with our kids and pets.
Then the temperatures fall, daylight disappears earlier, and surveys suggest many adults become more sedentary, especially those who are overweight. That's a mistake not only for your metabolism but also for your immune health.
Regular moderate exercise supports circulation, metabolic health, healthy inflammatory responses, and normal immune surveillance. It also helps maintain muscle, and I consider muscle one of our most important reserves for healthy aging.
Don't let cold weather turn winter into four months of sitting.
Ideally, you want to enter winter with as much metabolic resilience as possible, not spend the entire season losing strength.
That doesn't require hours at the gym, either. Aim for a combination of:
Daily walking
Resistance training several times per week
Mobility work
Outdoor activities you enjoy
Short walks after meals
Adequate protein is also important for maintaining muscle, particularly as you get older. Whole-food proteins should come first, but quality protein powders, branched-chain amino acids, or creatine can be useful tools for some people who struggle to meet their needs through food alone.
5. Letting the Holidays Become a Three-Month Sugar Binge
Starting around Halloween, we're surrounded by candy, cookies, desserts, sweetened drinks, party foods, and ultra-processed snacks.
I'm not suggesting you can never enjoy a piece of pie with your family. The problem is when an occasional celebration turns into an everyday way of eating from October through New Year's Day.
A diet dominated by added sugar and refined carbohydrates can contribute to poor blood sugar regulation, inflammation, and changes in the gut microbiome, all of which matter to your overall health and immune function.
Enjoy special foods when they're actually special, then return to the nutrient-rich foods that actually nourish you. The vast majority of the time, build your meals around:
Quality protein
Colorful vegetables and leafy greens
Citrus fruits and berries
Healthy fats such as olive oil and avocado
Fermented foods such as sauerkraut, kefir, and yogurt
Bone broth and other traditional foods
Herbs and spices, including garlic, oregano, thyme, and clove
Keep in mind that a healthy gut lays the groundwork for a stronger immune response, and that's why one of the best investments you can make before flu season is rebuilding your microbiome, such as with help from fermented vegetables, kefir or yogurt, bone broth, plenty of plant fiber, and a quality SBO probiotic supplement.
If you want additional support during cold and flu season, nutrients such as vitamin C, vitamin D, zinc, magnesium, KSM-66 ashwagandha, and medicinal mushrooms (such as reishi and turkey tail) can complement a nutrient-dense diet when appropriate.
Many of these, such as ashwagandha and magnesium, are useful for staying resilient against the effects of stress, too. The type of ashwagandha called KSM-66 has also been found to have anti-inflammatory, antioxidant, and anxiolytic effects.
Just remember, supplements can't rescue a lifestyle built around sugar, stress, sleepless nights, and inactivity.
The Bottom Line: Prepare for Winter Before It Arrives
Rather than fearing the cold and flu season, you can prepare for it. Before winter arrives, ask yourself:
Am I getting enough sunshine while it's still available?
Am I spending meaningful time outdoors?
Have I gotten my sleep schedule back on track?
Am I staying active and maintaining muscle?
Is most of my diet nourishing my body, or am I already slipping into months of holiday indulgence?
None of these habits is complicated, and that's precisely the point. God has already given us many of the most powerful tools for supporting our health: sunshine, fresh air, nourishing food, movement, sleep, community, and rest. Use them consistently now rather than waiting until you're sick to wish you had started sooner.
References:
https://pubmed.ncbi.nlm.nih.gov/39727935/
https://pubmed.ncbi.nlm.nih.gov/37686873/
https://pubmed.ncbi.nlm.nih.gov/36077185/
https://www.epa.gov/report-environment/indoor-air-quality
https://pubmed.ncbi.nlm.nih.gov/30920354/
https://pubmed.ncbi.nlm.nih.gov/26417606/
https://pmc.ncbi.nlm.nih.gov/articles/PMC10454497/
https://pmc.ncbi.nlm.nih.gov/articles/PMC6523821/
https://lifestylemedicine.stanford.edu/protein-needs-for-adults-50/
https://pmc.ncbi.nlm.nih.gov/articles/PMC12680924/
https://pubmed.ncbi.nlm.nih.gov/33803407/
