What Your Immune System Actually Needs Before Cold and Flu Season
What Your Immune System Actually Needs Before Cold and Flu Season
Lakshan WeeraratneSun, September 27, 2026 at 11:00 AM UTC
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1. Sleep, and the number matters
In a study where volunteers were exposed to a cold virus, those sleeping under six hours a night were more than four times as likely to get sick as those sleeping over seven. That was after controlling for age, stress, and health. Nothing in a capsule has an effect that size. If you are choosing between a 5 a.m. workout on five hours of sleep and the workout at lunch, take the sleep.
2. Regular moderate exercise, not heroic exercise
A study tracking roughly 1,000 adults through fall and winter found that people who exercised aerobically five or more days a week had about 43 percent fewer days with upper respiratory symptoms than those who trained one day or less. The gym itself is not the risk. Inconsistency is.
The mistake is the other direction. Very long, very hard sessions, especially marathon length efforts, temporarily suppress immune function for hours afterward. If you are training for a fall race, that is the week to sleep more, not less.
3. Vitamin D, if you are actually low
A large pooled analysis in The BMJ found vitamin D supplementation reduced respiratory infections modestly overall, with the biggest benefit in people who were deficient to begin with. If you work indoors and live north of Atlanta, a fall blood test is cheap, and a basic D3 supplement is the one thing most longevity experts still endorse.
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What to skip
Megadose vitamin C, immune gummies, and anything marketed as a “booster.” A ranked review of popular immune tactics puts most of them near the bottom. Zinc lozenges at the first sign of a cold have some support. That is about it.
When you do get sick
Head cold with no fever: light training is fine if it makes you feel better. Fever, body aches, or a chest cough: rest until you are fever free for 24 hours, then ease back. Training through the flu is how a week off becomes three.
This article is for informational purposes only and is not medical, legal, or financial advice. Consult a qualified professional before changing your training, diet, or supplement routine. The authors and publisher accept no liability for any loss or injury arising from use of this information.
This story was originally published by Men's Fitness on Sep 27, 2026, where it first appeared in the News section. Add Men's Fitness as a Preferred Source by clicking here.
Source: “AOL Breaking”
