Cortisol Explained: How Stress Can Affect Your Fitness - Jake Langham

Cortisol often gets a bad reputation in the fitness and health discussion, but it's actually an essential hormone that helps your body function, regulate energy and respond to stress.

The problem isn't cortisol itself. It's what can happen when you're constantly exposed to stress without giving your body enough opportunity to recover.

What Is Cortisol?

Cortisol is a hormone produced by your adrenal glands. Often called the stress hormone, it helps regulate blood sugar, metabolism, inflammation and your body's response to physical and psychological stress.

Cortisol naturally fluctuates throughout the day, typically peaking in the morning after waking and gradually declining towards bedtime. Levels also increase during exercise, helping mobilise energy to fuel physical activity.

Why Is Cortisol Good?

You actually need cortisol to function properly. It helps:

• Mobilise energy to fuel exercise and everyday activity.

• Regulate blood sugar levels.

• Support normal immune and inflammatory responses.

• Help your body respond to physical and psychological stress.

• Maintain normal metabolic function.

In short, cortisol is an important part of keeping your body functioning and responding to everyday demands.

When Can Cortisol Become a Problem?

Your body doesn't just experience stress during exercise. Work pressures, family responsibilities, poor sleep and inadequate nutrition all contribute to your overall stress load.

When these stressors become ongoing, they can disrupt normal cortisol regulation and make it harder for your body to recover, adapt and perform.Cortisol also influences how your body manages and uses energy. During periods of stress, it increases glucose availability to provide readily accessible fuel. Alongside changes in insulin sensitivity and other metabolic signals, ongoing stress can affect how efficiently your body mobilises and uses stored fat. Combined with disrupted sleep, increased appetite and changes in eating habits, this can make managing body composition and losing body fat more challenging.

You may notice:

• Persistent fatigue and low energy.

• Poor sleep irratability or difficulty switching off.

• Increased muscle soreness and slower recovery.

• Reduced strength, endurance and training performance.

• Stagnant progress despite consistent effort.

• Changes in appetite and food cravings.
  

This doesn't necessarily mean you have elevated cortisol, but it may be a sign that your overall stress and recovery balance needs attention.

Key Takeaways

You don't need to eliminate cortisol. You need to manage the demands you're placing on your body.

A few simple reminders:

• Aim for 7–9 hours of quality sleep.

• Prioritise protein intake and eat enough overall to support your training, recovery and daily activity.

• Balance hard training sessions with easier days and rest.

• Make time to switch off from work and everyday pressures.

• Recognise when you need to pull back rather than push harder.
  

Remember: Your body doesn't distinguish between a stressful day at work and a demanding training session when managing its overall stress load.

Training provides the stimulus, but recovery allows you to adapt. If you're constantly exhausted and struggling to make progress, the answer might not be another workout. It might be reducing the stress you're already carrying.

This article is for educational purposes only and is not intended to diagnose or treat any medical condition. Persistent or concerning symptoms should be discussed with a qualified healthcare professional.