Cortisol, often called the "stress hormone," impacts exercise and sleep cycles. It's why you need time between exercising and sleep. It's also why rest days, especially between intense workouts, are so important.
Definition of Cortisol
Cortisol is a glucocorticosteroid hormone. It secretes from the adrenal glands located on top of the kidneys. Cortisol secretion affects the function of nearly every system of your body! Your nervous system, immunity, cardiovascular health, respiratory system, musculoskeletal system, and integumentary system (skin, hair, nails, and nerves) are all impacted by cortisol production.
How Stress Affects Cortisol Levels
Cortisol helps regulate stress hormones in the body. While its release causes stress, the mechanism is to help us avoid danger. For example, cortisol release when being chased by a dog is a survival mechanism. In this example, our body springs into flight-or-fight mode, which is critical to human survival.
Fight or flight mode releases adrenaline, which stimulates cortisol production. Cortisol then stimulates the release of sugar from the liver to increase energy stores available for stressful situations.
Long-term stress, like a physically and emotionally stressful job, also increases cortisol levels. For example, first responders like ICU (Intensive Care Unit) nurses frequently run codes, save lives, and continually produce cortisol. Initially, this can help focus on the job. However, when cortisol levels remain high chronically, our bodies become inflamed.
Timing of Exercise, Sleep, and Cortisol Secretion
You may have exercised in the evening and struggled to go to sleep. Intense exercise will increase your cortisol levels, activating feelings of stress and restlessness in your body. The "exercise threshold effect" explains this phenomenon.
Moderate to high-intensity exercises increase cortisol levels. Low-intensity exercises do not produce high cortisol levels–they reduce it. Low-intensity exercises are 40% or less of your VO2 max (maximal oxygen uptake). Anything above 40% of your VO2 max is considered moderate to high-intensity. These findings explain the exercise threshold effect.
Cortisol makes your body feel aroused and increases focus and energy. Metabolism, blood sugar, the sleep-wake cycle, and inflammatory processes are all influenced by cortisol. Sleep is crucial to regulating cortisol release. And timing activity and rest help since many hormonal processes require quality rest for optimum function.
When it comes to activity and rest, timing is everything.
- Time your exercise. Regarding the sleep-wake cycle, your body naturally has lower cortisol levels in the evening and higher levels during the day. This means exercising earlier is better for healthy cortisol secretion.
- Time your meals. Meals stimulate cortisol release in our bodies. In a study that examined the effect of exercise on cortisol, exercising immediately after eating created a "blunted" cortisol effect. Avoid exercising on a full stomach to reap the maximum benefits of focus and energy from exercise.
- Rest in between workouts. Putting your body through consistent high-intensity workouts elevates cortisol levels. Therefore, it would be best to incorporate rest days, especially if you're doing a high-intensity training program.
How To Get Your Cortisol Levels Checked
You can test cortisol levels by blood, urine, or saliva samples. Levels depend on what time of day you get them checked.
Cortisol Level Ranges:
6 a.m. to 8 a.m.: 10 to 20 micrograms per deciliter (mcg/dL)
Around 4 p.m.: 3 to 10 mcg/dL
Cortisol peaks in the morning and is lowest at midnight. Remember that working overnight shifts or staying up late can affect this.
Five Tips to Get Your Cortisol in Sync
- "Exercises to relax." Breathing exercises, yoga, and meditation are all great ways to soothe your mind and body before bed. Try a guided meditation if you find it hard to sit still. Dim lighting also helps an activated nervous system, so create a soothing atmosphere in your home, especially in the evenings.
- Reduce stress. Do what you can to leave work at work, or have strict work boundaries if working from home. Let things go–meditation helps with this. Maintain healthy relationships, as this fosters a social connection that alleviates stress.
- Exercise early. Do intense exercise during peak cortisol excretion during the day. Eat after exercising to maximize the benefits of exercise-induced cortisol release.
- Incorporate rest days. It takes longer for your body to re-calibrate between high-intensity exercises. This is because hormonally, cortisol needs time to wind down and re-balance, too. Take at least a day off between high-intensity workouts.
- Try cryotherapy. One study demonstrated that after two whole-body cryotherapy sessions, cortisol decreased, and DHEA (Dehydroepiandrosterone, another adrenal hormone) was reduced. After 14 consecutive sessions, cortisol, DHEA, and estradiol (estrogen) decreased; testosterone increased.
Freeze your cortisol into control and book a cryotherapy session at Restore.
