It’s winter in Australia—and you can feel it in your bones. Cold mornings, fogged-up windshields, and the all-too-familiar sound of someone sneezing on the tram. It’s the season of running noses and running legs—and figuring out how to navigate both without burning out.

As runners, we’re wired to chase consistency. Progress is the product of routine, discipline, and showing up day after day. But what happens when our body says, Not today? When we’re dragging from a head cold, or worse, laid out with fever? This is where science meets common sense. It’s not just about knowing when to rest, it’s about knowing how to bounce back smarter—and stronger.

How Sickness Affects Training

When you’re sick, your body goes into battle mode. Energy and resources get rerouted to your immune system. That means:

Performance drops – Your pace, power, and endurance take a hit.
Fatigue spikes – Even an easy jog feels like a grind.
Injury risk climbs – Weakened systems can’t recover properly, making you more vulnerable.

Trying to train at full tilt during illness? That’s a fast track to extending your recovery time—or winding up worse.

Adjusting Your Training When You’re Sick

Let’s break it down.

Fever? Skip the run. If you’re battling chills, body aches, or a temperature, your body is already working overtime. Training can strain your system even further and raise the risk of serious complications.
Mild head cold? You can probably keep moving—but dial it way back. Easy walks, slow jogs, light mobility work. Nothing intense. Moderate movement might even help clear your head.
Stomach issues? Sit it out. Vomiting, diarrhea, and cramps can cause dehydration and mess with electrolyte balance. Pushing through can spiral into something much worse.

The key? Listen. Your body whispers before it screams.

Light Training Can Help—Sometimes

Light exercise like walking or yoga can actually support your immune system—when done right. Research shows moderate exercise boosts circulation of white blood cells, helping your body fight off invaders [Nieman & Wentz, 2019]. But there’s a difference between gentle movement and grinding through it.

Build a Stronger Immune System

Think of your immune system like your coach—it’s got your back, but only if you fuel it right.

1. Sleep like it’s your job.

7–9 hours minimum. Poor sleep wrecks immune function [Krueger & Majde, 2003].

2. Eat for defence.

Citrus fruits (vitamin C)
Berries (antioxidants)
Red meats & animal fats (iron, zinc, fat-soluble vitamins)

3. Hydrate properly.

8–10 glasses per day—more if you’re sweating. Electrolytes matter too.

4. Manage stress.

Deep breathing, meditation, hobbies—whatever keeps you grounded.

5. Train wisely.

Regular, moderate movement helps immunity. But too much volume with not enough recovery? That breaks you down, not builds you up.

The Nutrition-Immune Link

A few nutrients are heavy-hitters when it comes to immunity:

Vitamin C – Immune cell function and protection.
Vitamin D – Crucial for immune regulation. Sunshine, supplements, or fortified foods.
Zinc – Found in shellfish, red meat. Fuels immune activation.
Probiotics – Gut health is immune health. Think yogurt, kefir, sauerkraut.

Feed your defence system well. It pays you back in strength.

Own Your Immune System

We love to blame outside forces—the coughing coworker, the grubby kid on the bus—but more often than not, the real reason we get sick? A worn-down system we haven’t supported properly.

Overreaching in training? Guilty.
Skipping meals or eating junk? Been there.
Burning the candle at both ends? Classic.

Take ownership:

Rest when needed.
Fuel like an athlete.
Don’t glorify the grind if it’s costing your health.

Rest is Not Weakness

The reality: rest is training. Especially when you’re sick. Recovery lets your body rebuild, reset, and come back stronger.

Sleep extra.
Stay hydrated.
Eat nutrient-dense meals.
Avoid anything that spikes fatigue or stress.

Your progress doesn’t disappear from a few rest days—it disappears when you ignore what your body needs.

Coming Back After Sickness

Ease back in. No hero moves.

Start light. Walks, mobility, low-intensity runs.
Monitor symptoms. If fatigue creeps back or symptoms worsen, hit pause.
Check your ego. This isn’t about being tough—it’s about being smart.

Final Word

Every runner gets sick. It’s part of the game. But how you respond? That’s what separates the wise from the stubborn.

Adjust when needed. Rest like a pro. Nourish your system. Then come back with fire.

Train smart. Stay strong. Keep showing up.

And if you found this useful, share it with a friend.

Yours in sickness and in health,

Daniel Lucchini

References

Nieman, D. C., & Wentz, L. M. (2019). The compelling link between physical activity and the body's defense system. Journal of Sport and Health Science, 8(3), 201–217.
Krueger, J. M., & Majde, J. A. (2003). Humoral regulation of sleep. Nature Reviews Neuroscience, 4(2), 121–125.
Gleeson, M. (2007). Immune function in sport and exercise. Journal of Applied Physiology, 103(2), 693–699.

Running Through The Fog: How To Train When You’re Sick