If you’re training hard, eating light, popping supplements, grinding at work, or fasting long, your body might read it as stress, not biohacking.
A lot of “healthy” habits are only healthy in the right dose. Push them too far and your body can flip into stress mode, nudging inflammation upward. The tricky part: it often looks like discipline from the outside, while inside you’re stacking poor recovery, low fuel, and chronic strain. Below is what the research says about five common habits linked to higher inflammatory markers, plus the practical guardrails that keep them helpful instead of harmful.
Key Takeaways
- Overtraining can act like a chronic stressor, raising inflammatory signals when recovery is inadequate.
- Undereating (especially with hard training) can disrupt immune and redox balance, making recovery harder.
- Working very long weeks (≥61 hours) has been linked to higher risk of elevated hs-CRP (an inflammation marker).
- Prolonged fasting (≥48 hours) often shows a temporary rise in CRP/IL-6/TNF-α in studies.
- Supplements aren’t automatically benign, and some can trigger liver injury or inflammation signals in certain people.
1) Overexercising (when “more” becomes the stressor)
🔥 When training load rises faster than your recovery capacity, your body can treat exercise like a repeating injury signal. That can mean persistently elevated stress hormones, more muscle damage than you can repair, and immune changes that look pro-inflammatory over time.
What the research shows
- Intense exercise can create an acute inflammatory spike (a normal part of repair). The problem is when that spike becomes your baseline because recovery never catches up. Systematic reviews describe this “too much, too often” pattern as associated with pro-inflammatory effects and impaired immune function in overtraining contexts.
Signs you may be overdoing it
- Persistent fatigue, frequent niggling injuries, sleep disruption, unusually high resting heart rate, or performance that keeps slipping despite training.
Practical guardrails
- Hard days need easy days. Add at least 1–2 real recovery days/week (not “active recovery” that still crushes you).
- If you’re doing high intensity, protect the basics: sleep, carbs around training, and total calories.
2) Undereating (especially while training hard)
🍽️ If you chronically eat less than your body needs, you’re not just “cutting calories.” You’re reducing the energy available for immune function, hormone balance, and tissue repair.
What the research shows
- In controlled research on low energy availability (LEA), short periods of under-fueling have been shown to alter immune cell redox balance and inflammatory responses, including how the body reacts to an acute exercise bout.
- Reviews on LEA describe broad downstream effects on normal physiology, including systems tied to immune function and recovery.
Why this can raise inflammation
- When the body senses scarcity, it may shift into a conservation state that can increase physiological stress, impair recovery, and worsen training-related wear-and-tear.
Practical guardrails
- If you train most days, aim for protein + carbs at most meals, and don’t let “clean eating” become “not enough eating.”
- A simple tell: if your mood, sleep, hair, or performance is sliding, fuel is often the missing lever.
3) Taking too many supplements (or the wrong ones)
💊 Supplements can be useful, but “more” isn’t “better.” Some compounds have narrow safety windows, some interact with meds, and some can stress the liver or gut, which can feed inflammatory pathways.
What the research shows
- Herbal and dietary supplement–induced liver injury (HDS-DILI) is well documented in the medical literature, with outcomes ranging from mild enzyme elevations to severe injury.
- Some supplements marketed for body composition have shown inflammatory effects in trials. One classic example: conjugated linoleic acid (CLA) has been studied in humans with findings that include increased CRP and other inflammation-related signals in certain contexts.
Practical guardrails
- If you can’t explain why you take a supplement in one sentence (and what lab or symptom it’s targeting), reconsider it.
- Prefer “food first,” and if you do supplement: single-ingredient, reputable brand, reasonable dose, and bring your full list to your clinician.
4) Overexertion and chronic stress (including work overload)
🧯 Stress is not just “in your head.” It’s biology. Chronic stress can keep the body in a heightened state, influencing immune signaling and inflammatory markers.
What the research shows
- A cohort study found that working very long hours was associated with higher incidence of elevated high-sensitivity CRP (hs-CRP). Specifically, ≥61 hours/week showed higher odds versus ≤40 hours/week after adjustments.
Why this matters
- If your baseline is “always on,” your body may struggle to downshift into repair. That’s when inflammation-related symptoms (poor sleep, headaches, gut issues, frequent colds) can pile up.
Practical guardrails
- Build non-negotiables: a real lunch, daylight walk, device-off buffer before bed.
- If your schedule is fixed, focus on recovery rituals, not perfect habits.
5) Prolonged fasting (48+ hours is a different animal)
⏳ Intermittent fasting (like 12–14 hours overnight) isn’t the same as multi-day fasts. Once you hit 48 hours or longer, the body can interpret it as a major stressor.
What the research shows
- A 2025 review of prolonged fasting (≥48h) reports that many studies show rises in inflammatory biomarkers like CRP, IL-6, and TNF-α during the fast, often reflecting a stress response (and not always lasting after refeeding).
Practical guardrails
- If your goal is metabolic health, you often don’t need extremes. Many people do fine with 12–14 hours overnight and consistent nutrition quality.
- If fasting causes dizziness, sleep issues, irritability, or binge-rebound, that’s useful data: your plan is too aggressive.
Bottom line
A lot of inflammation reduction is boring: adequate fuel, smart training, real recovery, lower chronic stress, and fewer “hero” protocols. If a habit makes you feel progressively worse but looks “healthy” on paper, treat that as a red flag. Health is what your body can sustain.
Sources
- Beyond physical exhaustion: Understanding overtraining syndrome (2025)
https://pmc.ncbi.nlm.nih.gov/articles/PMC12010411/ - Low energy availability increases immune cell formation of inflammatory responses (2024)
https://pmc.ncbi.nlm.nih.gov/articles/PMC11260862/ - Cohort study of long working hours and increase in blood hs-CRP (2022)
https://pmc.ncbi.nlm.nih.gov/articles/PMC9470891/ - Long-term fasting and its influence on inflammatory biomarkers (≥48h) (2025)
https://pubmed.ncbi.nlm.nih.gov/40484176/
