When Less is More: Listening to your Body

Cortisol — An Athlete’s View From the Inside

If you train hard, you need cortisol. It’s essential, and when in balance, doesn’t cause damage. Cortisol is a glucocorticoid hormone released by the adrenal glands that helps mobilize glucose for energy, maintain blood pressure, and coordinate the body’s stress response so you can meet physical and mental demands (Cleveland Clinic, 2023). It also follows a daily rhythm called the circadian cortisol curve, where levels are normally higher in the morning and gradually decline through the day to support sleep at night (Endocrine Society, 2022). When that rhythm is working, you feel sharp in the morning and calm at night. When it’s off, you feel like you’re stuck in neutral with the engine revving.

1) How increased cortisol happens

From an athlete’s perspective, cortisol rises when your brain perceives load. That load can be physical training, psychological stress, lack of sleep, travel, illness, or under-fueling. The process runs through the hypothalamic–pituitary–adrenal (HPA) axis, where stress signals from the brain trigger adrenal cortisol release to increase alertness and energy availability (Tsigos & Chrousos, 2002).

This response is not bad in isolation. In fact, acute spikes in cortisol during hard sessions are normal and even helpful. The issue arises when stressors stack without adequate recovery. Research on overreaching and overtraining syndrome shows that chronic high training load combined with insufficient recovery and life stress can lead to neuroendocrine disruption that often includes altered cortisol patterns, mood disturbance, and performance decline (Kreher & Schwartz, 2012).

It’s also important to recognize that persistently elevated cortisol can sometimes be medical rather than training-related. Conditions such as Cushing syndrome involve long-term exposure to high cortisol and require clinical evaluation rather than more rest days or mindset changes (MedlinePlus, 2023).

2) What it feels like — the signs athletes notice

Athletes often describe chronically elevated or dysregulated cortisol with one phrase: “wired but tired.” You feel restless and stimulated, yet flat in performance and motivation. Sleep is frequently the first casualty — difficulty falling asleep, lighter sleep, or waking too early are common patterns when cortisol rhythms drift later into the evening (Endocrine Society, 2022).

Mood and perception shift as well. Research on overtraining consistently lists irritability, anxiety, and unexplained fatigue as early warning signs that the body’s stress systems are not recovering adequately (Kreher & Schwartz, 2012). From a physiological standpoint, prolonged cortisol elevation is also associated with higher blood pressure, increased blood glucose tendencies, appetite changes, and slower tissue recovery (Cleveland Clinic, 2023).

In more extreme or pathological hypercortisolism — again, medical territory rather than training stress — symptoms may include central weight gain, muscle weakness, thinning skin, and easy bruising (MedlinePlus, 2023). For most athletes, however, the early signals are subtler: sessions feel harder than they should, motivation dips, and recovery takes longer despite similar training loads.

3) How to prevent it — or bring it back down

The most effective cortisol management tools are not exotic supplements or hacks. They are sleep, recovery structure, fueling, and nervous-system regulation.

Sleep consistency is foundational. Because cortisol normally declines toward night, maintaining a regular wake time and protecting sleep duration helps preserve the natural hormonal rhythm that supports recovery and emotional stability (Endocrine Society, 2022).

Periodizing stress is equally important. The sports science literature emphasizes that alternating load with intentional recovery weeks reduces the likelihood of non-functional overreaching and endocrine disruption (Kreher & Schwartz, 2012). Life stress counts in this equation — hard training plus hard life equals compounded load.

Adequate fueling also matters. Cortisol partly exists to mobilize energy when resources appear scarce. Chronically under-eating, especially carbohydrates around demanding sessions, can keep the body in a prolonged stress state rather than allowing a return to baseline (Cleveland Clinic, 2023).

Finally, intentional relaxation practices such as mindfulness meditation and controlled breathing have demonstrated measurable cortisol-lowering effects in systematic reviews and meta-analyses (Pascoe et al., 2017). For athletes, this isn’t about becoming passive — it’s about training the parasympathetic system with the same seriousness used to train intervals or strength.

When the basics are aligned — sleep, structured recovery, proper nutrition, and deliberate nervous-system downshifting — cortisol becomes what it was meant to be: a performance ally rather than a silent saboteur.

Happy training,
Joe

References (in order of appearance)

Cleveland Clinic. (2023). Cortisol: What It Is & How It Affects Your Health.
Endocrine Society. (2022). The Cortisol Awakening Response and Circadian Rhythm Research.
Tsigos, C., & Chrousos, G. (2002). Hypothalamic–Pituitary–Adrenal Axis, Neuroendocrine Factors and Stress.
Kreher, J. B., & Schwartz, J. B. (2012). Overtraining Syndrome: A Practical Guide.
MedlinePlus. (2023). Cushing Syndrome.
Pascoe, M. C., Thompson, D. R., & Ski, C. F. (2017). Mindfulness Mediates the Physiological Markers of Stress: Systematic Review and Meta-Analysis.