Depression

What it is

Depression is a real condition with measurable biological correlates, not a mood or a character trait. It involves changes in brain-derived neurotrophic factor, inflammatory signalling, stress hormone regulation and the reward system - several of which exercise directly affects.

The evidence for exercise is strong: meta-analyses find effects comparable to psychotherapy and to antidepressant medication for mild to moderate depression. The cruel part is that the loss of motivation and energy is the illness itself, so the treatment requires the exact capacity that has been taken away.

What it feels like

• Persistent low mood most of the day, most days
• Loss of interest or pleasure in things that used to matter, which is often the more telling symptom
• Exhausted regardless of sleep, and everything taking more effort than it should
• Sleep and appetite disturbed in either direction
• Difficulty concentrating, and a harsh, flattened view of yourself and the future

What causes it

Most people have more than one of these at once, and they feed each other. Read the list looking for the two or three that sound like your week rather than for the one true answer — the ones that describe you are the ones worth acting on.

Reduced BDNF and neuroplasticity

Brain-derived neurotrophic factor supports the growth and connection of neurons and is reduced in depression. Aerobic exercise raises it reliably, which is one of the better-understood routes by which activity helps.

Chronic inflammation

Inflammatory markers are elevated in a substantial subgroup of people with depression, and inflammation produces sickness behaviour that looks a great deal like depression. Exercise reduces inflammatory signalling.

Dysregulated stress hormones

The cortisol system is often over-active and poorly regulated in depression. Regular exercise improves the responsiveness of that system rather than simply lowering it.

Behavioural withdrawal

Depression removes activity, activity provided reward and meaning, and their absence deepens the depression. Behavioural activation - deliberately restoring activity before the motivation returns - is an effective treatment in its own right.

Loss of self-efficacy

Repeated experience of not managing things erodes the belief that effort produces results. Exercise provides small, frequent, undeniable evidence to the contrary, which is a large part of why it works.

Poor sleep

Sleep disturbance both precedes and follows depression, and treating insomnia improves depression independently. It is one of the highest-value targets.

Life circumstances and loss

Bereavement, unemployment, isolation, caring, poverty and chronic illness all raise risk substantially. Naming this matters: not every depression is a chemical accident, and the physiology still needs support.

Chronic pain and physical illness

Depression is far more common alongside persistent pain and long-term conditions, and the relationship runs in both directions through shared pathways.

Genetics and previous episodes

Family history raises risk, and the strongest predictor of an episode is a previous one. This is a reason to build protective habits during good periods.

Isolation

Loneliness is an independent risk factor of substantial size. Group-based exercise addresses both the activity and the isolation at once, which is why it often outperforms solitary exercise in trials.

Who tends to get it

• Anyone with a previous episode, which is the single strongest predictor
• People with chronic pain or a long-term physical condition
• Anyone who is isolated or recently bereaved
• People sleeping badly over a sustained period
• Anyone with a family history of depression

What makes it worse, and what settles it

The qFIT routine for this

Ready-made routineStress & Anxiety Relief

qFIT already has this one built. It runs massage first, then stretching, then strength — the order that works on a body that is already sore — and every activity in it carries the reason it is there.

The button below opens your Checklist with this routine already selected, so instead of your whole list you land on just its Categories, Targets and Exercises, each with its checkbox, ready to tick as you work through them.

Have more than one problem? Tick yours under My Problems on My Profile and your Checklist's Routine list gains Recommended for my problems — every routine for the problems you picked, merged into one. Your picks stay private; that filter is the only thing they feed.

Get it checked if…

Suicidal ideation - urgent professional help; exercise is an adjunct not a substitute for treatment

And whatever the body part: chest pain or unusual breathlessness on exertion; a fever alongside the pain; unexplained weight loss; pain that is constant and unrelated to how you move; new numbness, weakness or loss of bladder or bowel control; or one calf that is swollen, warm and painful. Any of those, stop and get assessed.

How it usually goes

Exercise effects on mood build over four to twelve weeks, with some benefit noticeable much sooner, and the effect is dose-related up to a point. It works alongside talking therapy and medication rather than instead of them, and none of those is a failure to use. Severe depression, and any thoughts of self-harm or suicide, needs professional help promptly - that is not a situation for self-management, and asking for help is the correct move rather than a last resort.

Prevalence basis: National mental health surveys

Others the same routine covers

These share the Stress & Anxiety Relief routine, so the work is the same. If one of them also sounds like you, that is a reason to expect more from it, not less.

This is general information, not a diagnosis, and it cannot examine you. If it matches you, use it to ask better questions of a clinician rather than to replace one.