Article by Olivier Sanchez ND, NT Dip, Ir
You train more. Maxed your protein intake; maybe added some creatine. You are in bed by 10.00 PM. Yet, you’re more tired than you ever were. You do not sleep as well, somehow feel 'flat.' Despite your increased training load, your performance has stalled, perhaps even declining, and you experience persistent muscle soreness. You are doing everything 'right,' and yet you’re getting weaker, not stronger.
What you are experiencing fits a recognised physiological pattern: overtraining syndrome. It is also a signal that your training load has outpaced your recovery capacity.
A short‑term burst in cortisol during and after exercise is normal and necessary. It helps mobilise glucose, supports the immune response to exercise‑induced muscle damage, and is part of the hormonal environment that drives adaptation.
It only becomes a problem when cortisol stays elevated because the training load consistently exceeds your body’s ability to recover.
A brief cortisol spike during training is a useful stress signal, acting specifically as a catabolic signal that triggers the body to break down tissues for fuel. This necessary breakdown is what jump-starts recovery and anabolic rebuilding phases, leading to stronger muscles.
The key is to allow your body to recover properly so cortisol levels can return to their natural baseline.
Again, when training volume or intensity consistently exceeds recovery capacity, cortisol remains elevated between sessions. This shifts the hormonal environment from anabolic (building) to catabolic (breaking down). Instead of repairing and growing, the body starts “cannibalising” lean muscle for fuel. This also explains why you stop noticing progress or worse performance, and fatigue accumulates session after session.
Chronically elevated cortisol doesn’t just make you feel tired. It affects physiological pathways at a cellular level.
High cortisol promotes protein catabolism (the breakdown of muscle tissue for energy). This is exactly the opposite of what you are trying to achieve with training. As a result, strength plateaus, you find it more difficult to maintain muscle mass, and to recover. You’re putting in more work but getting less return.
Cortisol is anti‑inflammatory. This is very useful if you are trying to escape danger and you’re injured. However, persistent high cortisol is a problem because it suppresses immune function. This explains why overtrained athletes frequently get ill. If you’re training hard and catching every cold that goes around, this is one mechanism.
Another mechanism to keep in mind is evening pain. As cortisol levels drop and its anti-inflammatory properties dissipate, you may experience muscle pain, which can make it harder for you to relax and fall asleep.
Cortisol and melatonin are in direct opposition. Chronically elevated training cortisol delays the evening cortisol decline, suppresses melatonin and disrupts sleep architecture. Poor sleep then impairs recovery. This creates a vicious cycle: bad sleep leads to worse training, which leads to worse sleep, more pain and greater susceptibility to infection.
When the adrenal glands are chronically diverting resources, including cholesterol, to cortisol production, testosterone synthesis may be compromised.
Studies have identified that chronically elevated cortisol is associated with lower free testosterone, which affects muscle building, as well as mood, libido, energy, and cognitive function. This is the men’s health angle most fitness content ignores entirely.
Signs of a disrupted testosterone–cortisol ratio: Common signs include:
These can overlap with other conditions; however, in the context of excessive training and lower performance, they are indications that the stress system is overloaded.
Use the checklist below, and if several of these fit, it’s worth considering whether your training load is too high for your current recovery capacity:
If this looks familiar, the solution is to stop training 'hard,' reduce the load, and support recovery.
Here are some techniques to consider:
Adding rest to your routine is the single most important intervention. Consider 'de-load' phases, typically lasting 5 to 7 days of reduced‑intensity, and adequate recovery between sessions, to allow cortisol to fall and anabolic signals to dominate again. Think of it as training 'intelligently,' so progress can continue.
Natural healing and repair only occur during deep sleep. Improving sleep quality is thus the highest‑impact recovery intervention you can control. That means consistent sleep patterns, a wind‑down routine, and minimising late‑evening stimulation. Do not exercise too close to bedtime, to ensure higher body temperature does not impact sleep onset.
Magnesium is required for muscle relaxation, protein synthesis and cortisol metabolism. Deficiency is common in athletes due to losses through sweat. Replenishing electrolytes, including magnesium (through food and, where appropriate, supplementation), will support muscle recovery and stress system regulation.
Standardised ashwagandha extracts such as KSM‑66® have specific evidence in athletic populations, reducing cortisol, improving recovery time, and supporting testosterone levels in men. The effect builds over several weeks and is best combined with sensible training and sleep.
Protein within two hours post‑training helps shift the hormonal environment from catabolic back toward anabolic. For a more potent effect on muscle building, the best window is 30 minutes. Combine protein with healthy fat; think protein shake with avocado and pumpkin or hulled hemp seeds.
When you’re already overtrained, focusing on more HIIT, extra caffeine to push through fatigue and cutting calories to 'get leaner' all push cortisol higher. Instead of allowing your body to build muscle and recover, these habits keep the stress system switched on. Cortisol remains constantly high, repair is compromised, and fatigue establishes itself deeper. This pattern is not helping you progress; it’s maintaining the cycle that’s making you weaker.
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Olivier Sanchez is a registered naturopath and naturopathic nutritionist, an internationally published author, and the founder of Nutrunity. He specialises in digestive, metabolic, and mental well-being, with a key focus on gut health and sleep, helping individuals create sustainable routines that enhance energy, focus, and overall health.
You may also enjoy reading:
Hawley, CJ., Schoene, RB. (2003). Overtraining syndrome: A guide to diagnosis, treatment, and prevention. The Physician and Sports Medicine. 31(6), pp. 25-31. doi:10.3810/psm.2003.06.396
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