Cognitive Load and Burnout: Why You’re Tired Even When You’re Not Training Hard

There are seasons when you’re not training intensely, not logging long workouts, and not pushing your body to its limits, yet you feel completely exhausted.

This kind of fatigue can be confusing. You might even catch yourself thinking, “Why am I so tired? I’m not doing that much.”

But here’s the truth: fatigue isn’t only physical. In many cases, it’s cognitive.

What Cognitive Load Really Is

Cognitive load refers to the amount of mental effort being used at any given time. Every decision, every unfamiliar environment, every new task pulls from the same finite pool of mental resources.

Research on decision fatigue and cognitive overload shows that sustained mental effort can be just as draining, if not more so, than physical work. When the brain is constantly processing new information, problem-solving, and adapting, the nervous system stays in a heightened state of alert.

Over time, that leads to exhaustion.

When Life Becomes the Workout

Recently, my husband and I PCS’d (moved) per the military to Belgium. Physically, our training volume dropped. Mentally, the load skyrocketed.

New country.
New systems.
New procedures.
New routines.
New languages and cultural norms.

Every simple task required thought. Nothing was automatic.

Moving is taxing on its own, but relocating internationally adds a layer of constant decision-making and uncertainty. And it forced me to acknowledge something I’ve coached others through for years: mental stress counts.

Even without hard training sessions, both of us felt drained. Not sore, but depleted.

Why Mental Fatigue Hits So Hard

Unlike physical training, mental load often goes unrecognized. There’s no obvious “muscle soreness” equivalent to signal the need for recovery.

Yet the brain consumes a disproportionate amount of energy. Prolonged cognitive effort increases cortisol, taxes executive function, and reduces emotional regulation capacity. This is why people feel irritable, foggy, or unmotivated even when their bodies haven’t been pushed.

In resilience research, this is a classic setup for burnout: high demand, low recovery.

Rest Isn’t Just for Physical Training

This season reminded me, and my husband, that rest is not something you earn through physical exhaustion alone. Mental stimulation requires recovery too.

Rest can look like:

• Lower training volume without guilt

• Simpler workouts that reduce decision-making

• More sleep and unstructured downtime

• Reduced expectations around productivity

• Earlier bedtimes and increased sleep durations

And perhaps most importantly: permission to be tired without judgment.

Being mentally exhausted is just as valid as being physically tired.

Resilience-First Programming in High Cognitive Load Seasons

This is where resilience-first coaching matters.

Instead of pushing harder, resilience-focused programming asks:

• What is your total stress load right now?

• Where can we reduce friction?

• How do we maintain consistency without overload?

Sometimes the most resilient choice is maintenance, not progression.

Training becomes a stabilizer, not another demand.

The Takeaway

If you’re feeling exhausted in a season where you’re not training hard, you’re not broken, and you’re not lazy.

You’re likely carrying a high cognitive load.

Life transitions, decision-heavy environments, emotional stress, and uncertainty all tax the nervous system. And just like physical exertion, they require recovery.

Resilience isn’t about pushing through everything.
It’s about recognizing what kind of load you’re carrying, and responding wisely.

And right now, that wisdom might look like rest.