The Secret Body Clock That Controls Your Energy (And How to Master It)
Your body runs on short cycles that change how you feel and work throughout the day.
What Are These Short Rhythms?
Your body follows short cycles that repeat many times each day, creating ups and downs in your energy, focus, and brain power.
These cycles run in 90-120 minute blocks, switching between high-energy periods (when you focus best) and low-energy recovery times (when you need a break).
Unlike the 24-hour sleep-wake cycle, these short rhythms affect you many times each day.
The name “ultradian” comes from Latin, meaning "many times a day," which fits how these cycles work.
They control:
Brain activity patterns
Hormone release
Energy ups and downs
Focus ability
Body temperature changes
What makes this exciting? These aren't just feelings—they're real, measurable changes happening in your body.
The Science Behind Your Energy Waves
Your brain creates a pattern of peak performance followed by needed rest that affects how well you think throughout the day.
During high-energy phases, your brain shows more activity, especially in areas that handle focus and decisions.
This happens when brain chemicals tied to alertness and focus, like dopamine and norepinephrine, reach their highest levels.
These chemical shifts create the waves of energy and mental clarity you feel.
And the research shows:
Brain wave tests reveal changes that match these short cycles
How well you do on thinking tasks goes up and down with these brain patterns
Hormones, including stress hormones, follow these short cycles
Even body temperature rises and falls throughout the day
These rhythms affect both performance and mood.
This means these cycles change both how you perform and how you feel about your performance.
Short Rhythms and Your Health
These natural cycles keep you healthy by controlling key body processes and helping you recover from stress.
These cycles affect many health functions, from hormone release to metabolism and stress response.
Disrupting these rhythms can harm both physical and mental health.
These cycles control cortisol, your main stress hormone.
Rather than a steady release, cortisol comes in pulses about once per hour.
This pulse pattern helps maintain proper stress response and recovery.
And there are several important connections with health:
Disrupted cortisol cycles link to higher stress risk
Proper cycling helps keep metabolism and energy balanced
Brain health needs intact cycles, with disruptions tied to brain problems
Growth hormone peaks about every 3-4 hours
Cell repair processes follow these short cycles
Reduced brain activity cycles matched with unhealthy tissue, regardless of brain region.
This suggests healthy brain function needs properly working short cycles.
Most fascinating? These rhythms adapt to your energy needs.
When you're low on energy (like during fasting), these cycles grow stronger, while high energy states make them less noticeable.
This adaptive system helps your body respond to changing energy demands.
Boosting Work Energy With Your Natural Cycles
Working with your body's natural rhythms instead of fighting them can improve your focus, energy use, and total output.
The typical work cycle runs 90-120 minutes of high energy followed by a 20-30 minute rest period.
By matching hard tasks to your natural peaks and taking breaks during your natural dips, you can work better while cutting tiredness and burnout.
This approach differs from the common "push through" mindset in many workplaces.
When you ignore your body's need for breaks, you fight against your biology—a battle you'll lose through worse performance, more mistakes, and possible burnout.
Here's how to use a rhythm-based work approach:
Schedule your hardest, focus-heavy work during peak energy times
Take planned 15-20 minute breaks when you notice your energy and focus dropping
Use breaks for true rest—movement, water, or quick relaxation—not just checking email
Try combining these rhythms with methods like Pomodoro (25 minutes of work, 5-minute breaks)
Track your energy for a few days to find your personal cycle timing
By matching your work schedule to these natural peaks, you can get the most from your brain power.
What makes this approach powerful?
It lasts.
Rather than using willpower or caffeine to push through tiredness, you work with your body's natural energy system.
This leads to better short-term performance and improved long-term output and health.
Brain Performance and Short Rhythms
Your thinking skills—from creative ideas to problem-solving—change throughout the day according to your body's natural cycles.
During peak cycle phases, your brain works at its best.
This is when you focus deeply, process complex information, and generate creative ideas most easily.
During low phases, your thinking skills drop as your brain enters “recovery mode”.
Thses are key thinking functions that follow these patterns:
Attention span and focus
Problem-solving and logical thinking
Creative thinking and new ideas
Decision-making quality and speed
Memory creation and recall
Even after disrupting these rhythms, stress responses stayed changed even after hormone patterns returned to normal.
This suggests these rhythms affect not just how we think but also how we respond to challenges.
Conclusion: Dancing With Your Rhythms
Your body's natural short cycles offer a powerful way to improve both your work energy and health when you learn to work with them, not against them.
These natural cycles—happening about every 90-120 minutes throughout your day—affect everything from your thinking skills to your stress response and health.
By understanding and respecting these rhythms, you can change how you approach work, rest, and health management.
The key insight?
Fighting these rhythms backfires.
When you push through natural energy dips without breaks, you borrow energy from future performance, and that debt comes due through decreased energy, more mistakes, and possible burnout.
Instead, by matching your activities to your natural energy flows (planning hard work during peaks and taking breaks during dips), you create a lasting approach to productivity that works with your biology.
This isn't just about doing more; it's about working in a way that supports your long-term health and performance.
References
Blum, I. D., Zhu, L., Moquin, L., Kokoeva, M. V., Gratton, A., Giros, B., & Storch, K. F. (2014). A highly tunable dopaminergic oscillator generates ultradian rhythms of behavioral arousal. eLife, 3, e05105. https://doi.org/10.7554/eLife.05105
Goh, G. H., Maloney, S. K., Mark, P. J., & Blache, D. (2019). Episodic Ultradian Events—Ultradian Rhythms. Biology, 8(1), 15. https://doi.org/10.3390/biology8010015
Gerkema, M.P. (2002). Ultradian Rhythms. In: Kumar, V. (eds) Biological Rhythms. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-06085-8_17
Hayashi, M., Sato, K., & Hori, T. (1994). Ultradian rhythms in task performance, self-evaluation, and EEG activity. Perceptual and motor skills, 79(2), 791–800. https://doi.org/10.2466/pms.1994.79.2.791
Lightman, S. L., & Conway‐Campbell, B. L. (2024). Circadian and ultradian rhythms: Clinical implications. Journal of Internal Medicine, 296(2), 121-138.