When the ward breaks you… and movement puts you back together
When you work as a junior doctor in Africa, you go through some tough times. I still remember that rotation: long shifts, bleary-eyed nights, spending entire weekends on call in the hospital, ‘stealing’ a couple of hours of sleep on the couch in the staff tea-room. The work was intense, stress levels through the roof, immense responsibility despite lack of maturity and lack of experience. The “rest of life” got squeezed into whatever scraps were left. I recall many occasions when I would sit on my couch and the tears would just stream down my cheeks… from exhaustion and emotional depletion. We all had a hard time.
But, one colleague of mine didn’t just struggle under the pressure — she unravelled.
At first it looked like what many of us do when we’re running on fumes: more coffee, more convenience food, more sugar “just to get through”. Then the drinking crept in. Then it wasn’t “creeping” anymore — it was heavy, regular, and clearly doing more harm than relief.
She became quieter. More withdrawn. She lost weight. Her mood flattened into something that felt frighteningly distant. She became less reliable, turning up late or forgetting she was on call. And then, the part that makes my stomach tighten even now: she started making major clinical mistakes.
It escalated quickly: a disciplinary hearing, mandatory sick leave, months away from work.
When she eventually returned, I hardly recognised her — not because she looked different (although she did), but because her energy was different. Grounded. Cheerful. Present. Functioning. Balanced.
I assumed she’d seen a psychiatrist, started antidepressants, maybe had structured therapy.
But she said something that surprised me:
“I didn’t want conventional treatment for my psychological problems. I knew medication wouldn’t be the long-term answer for me because I had already tried to treat myself with caffeine and alcohol. I had to change what I was ‘physically doing’ to cope with my situation.”
Her “treatment” was exercise.
She joined a gym and became, in her words, a bit obsessional about it. She attended all the group classes (step class, abs and glutes, kick-boxing, spinning, dance, aerobics). Within weeks, she started feeling better — and movement became her coping strategy.
When she returned to work, the stressors were the same. The workload was the same. The emotional demands were the same. But, she discovered that exercise allowed her to evacuate the stress in an adaptive and positive way. She had more physical energy and mental alertness.
She went on to specialise in internal medicine… one of the most academically challenging, exhausting and detailed specialities in the medical field. And, she never needed to take medication.
This post is about why her strategy makes physiological sense, which brain chemicals are involved, and how you can use exercise as a practical tool for depression, anxiety, stress, and sleep.
(Please note: exercise can be powerful, but it’s not a substitute for urgent mental health support when someone is at risk of harm to themselves or others. I’ll come back to that.)
Why exercise changes your mind
Exercise doesn’t “just distract you”. It changes the chemistry and biology of the brain and body in ways that directly affect mood, anxiety, and sleep.
Here are some of the key players:
1) Serotonin, dopamine, and noradrenaline (your motivation + mood circuit)
Physical activity influences monoamines (including dopamine, noradrenaline, and serotonin) — neurotransmitters involved in mood, drive, focus, and emotional regulation.
Think of these as part of the brain’s “get-up-and-go” and “feel-good” system. When they’re low or dysregulated, everything feels harder: motivation, concentration, hope, pleasure. Even basic daily functions like personal hygiene become major obstacles requiring a lot of persuasion.
When I was working night-shift I always stopped at the gym on the way home in the morning. I was exhausted, often grumpy because there were inevitably unnecessary and annoying cases (like drunk students with nausea and vomiting) that had kept me up all night. But, as soon as the warm-up started in my Zumba class… I could feel the misery leave me. By the time the warm-up was over, the physical soreness and stiffness was gone, and I couldn’t remove the smile from my face. On the way home from gym, it was like the stress of the previous night had been erased. I was happy and relaxed.
2) Endorphins and endocannabinoids (your built-in calming and pain-relief system)
You’ve heard of the “runner’s high”. While endorphins play a role, endocannabinoids are also strongly implicated in the mood-lift and anxiety-reduction that can follow aerobic exercise. Any activity that causes your heart to beat faster, deep breathing and makes you break a sweat can leave you feeling more cheerful and less stressed.
This matters because stress and depression often come with a body that feels tense, restless, or numb. These systems help the body feel safer and more comfortable in itself. I’ve never heard anyone leaving the gym after a great workout saying: “I really regret today’s training”. Instead, you hear phrases like: “Wow! My legs are shaking but I feel fantastic now!”
3) BDNF (brain fertiliser for resilience)
BDNF (brain-derived neurotrophic factor) supports brain plasticity — the ability to adapt, learn, and recover. BDNF plays a major role in the formation of new neural pathways. Chronic stress and depression are associated with reduced plasticity; exercise tends to push in the opposite direction.
In plain language: movement helps your brain adapt and increase its capacity for change under challenging circumstances. Physical activity boosts neurological resilience. Doing regular exercise that involves physical challenges helps banish brain fog.
4) The stress system (HPA axis + cortisol)
Exercise is a controlled stressor — the useful kind. Over time, it can improve stress regulation and reduce the “always-on” physiological stress state that fuels anxiety, low mood, cravings, hyper-vigilance and poor sleep.
One of my patients, a single mother and remedial teacher, came to me with burn-out. Physical and mental depletion. She was struggling to get up in the morning. Despite eating a very well-balanced diet, she had gained more than 10kg in the preceding 6 months and she noticed her belly had become ‘jiggly’. She had previously enjoyed running… but life had become so full of other priorities that she neglected her sport in favour of caring for her kids and attending to her responsibilities at work. Her blood cortisol level was 3 times the upper limit.
I asked her to take 2 weeks off work, re-structure her schedule so she could include just 20 minutes of exercise 3 days per week.
The transformation was quite amazing. Withing 3 months, her belly was flat again, and she was feeling in control of her life. Her job was the same, her kids still needed the same amount of attention but she had changed her routine to include exercise that she enjoyed and that had positive physiological effects her body and her brain.
5) Inflammation and sleep
Regular physical activity is associated with reduced systemic inflammation and improvements in sleep quality and efficiency — both closely tied to mood and anxiety symptoms.
A powerful real-life example of this is one of my patients with ankylosing spondylitis (a nasty auto-immune condition that causes inflammation in the spine that results in debilitating pain and often severe disability). He decided that he would try yoga to improve his flexibility. After 6-7 months of regular classes (with not other change in lifestyle or medication), his inflammation levels in his blood decreased to normal. We were able to reduce his chronic anti-inflammatory medicine to ‘as needed’ instead of daily doses. Besides experiencing less pain and improved mobility, he said: “Yoga saved my life. I feel like a different, happy person now”.
But, is all exercise equal when it comes to health and nerve-system benefits?
Different types of exercise, different brain effects
Not all movement feels the same — and that’s the point. If you match the type of movement to the symptom, you can often get a better result.
A) Aerobic exercise (walking, jogging, cycling, swimming)
Best for: low mood, stress overload, mental fog, mild–moderate anxiety
Key mechanisms: monoamines, endocannabinoids, BDNF, stress regulation
If someone says, “I feel heavy, flat, unmotivated, and my head is full of cotton wool,” aerobic movement is often the fastest way to shift state. 2-3 minutes of intense aerobic activity is all you need to feel a mood boost. If intense exercise is not your thing, then 10 minutes of moderate exercise will do the trick.
B) Strength training (weights, resistance bands, bodyweight)
Best for: depression with low confidence/low agency, rumination, fragile self-worth
Key mechanisms: mood pathways + psychological leverage (competence, self-efficacy, identity shift)
A major meta-analysis (the highest level of quality clinical research) found exercise is an effective treatment for depression, with strength training (along with walking/jogging and yoga) showing particularly strong effects.
Strength training also gives people something depression often steals: a measurable sense of progress. You can physically see and feel the changes in your body as you gain strength and power.
C) Yoga / tai chi / mindful movement
Best for: anxiety, stress dysregulation, sleep problems, “wired but tired”
Key mechanisms: autonomic nervous system shift (more parasympathetic tone), downshifting arousal; also effective for depression
This is the lane for people who don’t need more intensity — they need more safety in their nervous system.
D) HIIT (high-intensity intervals)
Best for: some people with low mood and low energy who enjoy intensity and thrive on conquering challenges
Caution: if someone is anxious, overstimulated, sleep-deprived, or burnt out, HIIT can be counter-productive and feel like petrol on a fire.
HIIT can increase arousal and stress hormones acutely; for some it’s empowering, for others it worsens jitteriness and may worsen sleep. Timing matters (more on sleep below).
So, how do you get started when life already feels like it’s too heavy to handle?
Using exercise for specific mental health goals
1) Depression: “I can’t get myself to do anything.”
Start tiny. The goal isn’t fitness — it’s momentum.
The evidence is clear: exercise can meaningfully reduce depressive symptoms. Specifically, walking/jogging, strength training, and yoga perform well in clinical research studies.
Practical approach:
- Minimum effective start: 10 minutes brisk walking daily for 7 days.
- Add 2 strength sessions/week (even 15–20 minutes at home).
- Add 1 calming session/week (yoga, stretching, mobility).
Why this works: it hits mood chemistry, self-efficacy, and stress regulation from different angles.
2) Anxiety: “My body feels on edge.”
Anxiety isn’t just thoughts — it’s a body state of tension and hyper-alertness. You can break the cycle by doing 10-15 minutes of specific activities that reduce the physical stress response:
Best starting tools:
- Moderately intense aerobic exercise – ‘Zone 2’ (you can talk, but you’re breathing a little more rapidly and you’re warm) – brisk walking / gentle jogging, swimming, cycling, rowing, line-dancing etc
- Mind-body movement (yoga/tai chi)
These can reduce physiological arousal and give the brain a new signal: you are safe enough to move, breathe, and recover.
If panic is prominent, start with short, predictable movement: 5–10 minutes, same route, same time, same music — make it feel safe with no potential surprises.
3) Insomnia: “I’m exhausted but I can’t sleep.”
Exercise improves sleep quality and efficiency in many people with insomnia, especially when it’s consistent and moderate.
What tends to work best:
- Moderate-intensity aerobic exercise (e.g., brisk walking) 30 minutes, 3x/week
- Mind-body (yoga/tai chi) if you’re wired at night
Timing tip: vigorous exercise too close to bedtime can disrupt sleep for some people; exercise earlier in the day is often easier on the nervous system and better for sleep.
The “Exercise Prescription” (simple, realistic, effective)
If you want a structure that works for most people:
Week 1–2: Stabilise
- Daily: 10–20 minutes walking (outside if possible)
- Twice weekly: 15 minutes strength (squats, lunges, push-ups against a wall, rows with a resistance band, weight training)
- Once weekly: 20 minutes yoga/stretching
Week 3–6: Build
- Aerobic: 150 minutes/week moderate activity (or work gradually towards it)
- Strength: 2 days/week (train all your major muscle groups)
- Optional: one session that’s purely for fun (dance, hiking, team sport)
Week 7 onward: Personalise
Choose based on your brain:
- Low mood → more aerobic + strength
- Anxiety → more zone 2 + mind-body
- Insomnia → consistent moderate + earlier timing + calming mobility in evenings
Advice to anyone facing burn-out, or physical or mental exhaustion
If you’re reading this as someone in a pressure-cooker, during a time of your life where the demands on you seem overwhelming — occupational responsibilities, parenting, exams, entrepreneurship, caregiving — here’s the uncomfortable truth:
When life is particularly tough, your brain needs movement most… and that’s exactly when it feels hardest to do it.
So don’t aim for perfect. Aim for non-negotiable minimums.
- 10 minutes counts.
- Walking counts.
- Stretching counts.
- “I did it even though I didn’t feel like it” counts the most.
A word of caution: when exercise isn’t enough on its own
Exercise can be a cornerstone, but please don’t use it to white-knuckle through something dangerous.
If you (or someone you care about) has:
- destructive or suicidal thoughts or self-harm urges, or feeling unsafe
- severe functional impairment (can’t work, can’t eat, can’t perform self-care)
- symptoms of mania/hypomania (reduced need for sleep, racing thoughts, risky behaviour)
- substance dependence or abuse that’s escalating
…that’s a now problem, not a “gym will fix it” problem. Exercise can sit alongside proper care — not replace it. Please see a healthcare professional for support and advice on management that best suits you and your personal situation.
Here are some questions for you to reflect on:
- When you feel mentally worse, what changes first: sleep, food, alcohol, movement, connection? Becoming more aware of how you change when you feel stressed can help you identify when you need to adapt your routine, behaviour, current strategy to prevent spiralling and burning out.
- What type of movement leaves you feeling calmer and happier: walking, lifting, yoga, dancing? If you know what fuels you… try to do it more often.
- What is your “minimum non-negotiable” on hard days? (5 minutes? 10 minutes?) By defining your worst case scenario, you identify your baseline minimum that is realistically achievable and you should manage to do this (if not more) on most days.
- What would make exercise easier this week: a friend, a class, a schedule, a nearby route? What are practical ways you can remove barriers and friction and enable you to move more, and more regularly?
If you would like to download a guide on physical activity… with specific recommendations to improve your overall well-being, consider the following resources:
STARTING OUT WITH EXERCISE HANDOUT