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Feeling tired after 30 even with sleep and exercise? Dr. Joshua Nderitu, a family physician, explains the real causes of low energy and simple, science-based ways to fix it.
If you are over 30 and feel tired most days—even after sleeping—you are not alone.
In my clinic in Nairobi and Machakos, I hear this often:
“Doctor, I used to have energy. Now I’m tired all the time.”
Many people think this is just aging.
It is not.
The truth is this: energy drops after 30 because of small body changes combined with modern lifestyle habits. The good news? These changes are reversible.
What if the next 90 days could rewrite your next 30 years? Let’s explain why your energy is low—and what actually works.
Why Energy Drops After 30
1. Muscle Loss Slows Energy
From around age 30, adults lose about 3–8% of muscle per decade if they are inactive. Muscle helps the body use food to make energy. When muscle reduces, energy production becomes less efficient, and fatigue increases.
2. Stress Hormones Stay High
Busy work schedules, long commutes, family responsibility, and financial pressure keep the stress hormone cortisol high. When cortisol remains elevated, sleep quality drops, blood sugar becomes unstable, and the body feels constantly tired.
3. Sleep Quality Declines
Many adults sleep enough hours but do not sleep deeply. Late-night screen use, caffeine, stress, and irregular schedules prevent restorative sleep. Without deep sleep, the body fails to repair itself overnight.
4. Blood Sugar Swings
High-carbohydrate meals without enough protein or fiber cause sugar spikes and crashes. This leads to afternoon fatigue, irritability, and poor concentration—very common in people at risk of diabetes or prediabetes.
5. Dehydration and Nutrient Deficiency
Chronic dehydration, iron deficiency, vitamin B12 deficiency, and vitamin D deficiency are common causes of fatigue in Kenya and often go undetected.
A Real Patient Story
Janet is a 35-year-old professional working in a construction firm in Nairobi. She exercised regularly and tried to eat well, yet felt exhausted daily.
On deeper review, we found she was scrolling on her phone late into the night, disrupting her sleep. With simple changes—stopping phone use at night, improving sleep routine, balancing meals, and gentle daily movement—her energy returned.
Today, Janet attends regular check-ups and is thriving, not just surviving.
Medical Conditions That Can Cause Chronic Fatigue
Not all fatigue is lifestyle-related. Some medical causes include:
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Anaemia (low iron)
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Thyroid disorders
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Diabetes or prediabetes
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Sleep disorders such as sleep apnea
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Depression and anxiety
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Chronic infections or inflammation
Some medications—such as certain blood pressure drugs, antihistamines, antidepressants, and sleep medications—can also cause tiredness. Always discuss symptoms with your doctor before stopping medication.
Seek medical review if fatigue lasts more than 2–3 weeks, worsens, or comes with weight loss, breathlessness, or fever.
Simple Habits That Restore Energy
You do not need extreme changes. Start small:
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Move daily: 20–30 minutes of walking or light strength exercise
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Protect sleep: Same bedtime, no screens one hour before bed
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Eat balanced meals: Protein + vegetables + healthy fats
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Drink enough water: 2–3 litres daily
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Manage stress: Prayer, breathing, or quiet time daily
Small daily habits create lasting energy.