By Teresa Alasio
We have all heard and read recommendations from medical experts, fitness gurus and even official government offices about how much exercise adults and children need to stay healthy and live longer lives. According to the American Heart Association, if adults get at least 150 minutes of moderate aerobic activity, like brisk walking, or 75 minutes of vigorous activity, like running, in addition to muscle strengthening exercises and balance activities, our hearts stay pumping longer and better. Similarly, the Presidential Fitness Test, which was developed in the 1950’s to combat obesity, chronic disease and improve strength among our young people, looks to maintain the bodies of our young people.
But did you ever hear about how exercise affects the brain?
When considering whether or not to engage in physical exercise, it’s important to be aware that movement doesn’t just shape your body, it reshapes your brain. Exercise boosts the production of brain-derived neurotrophic factor (BDNF), shifts key hormones like atrial natriuretic peptide (ANP), and even changes the structure of brain regions tied to memory, focus, and emotional balance. These transformations help explain why staying active can ease depression and anxiety, sharpen attention in ADHD, and enhance executive function, the mental control center in your prefrontal cortex.
To bring this all into the public spotlight, psychiatrist John J. Ratey, through his influential book Spark, argued that aerobic exercise is one of the most effective tools for improving mood, thinking, and learning. In his book, Ratey weaves together decades of research showing that raising your heart rate kicks off a biochemical chain reaction that primes the brain for change, a process known as neuroplasticity. He uses multiple examples from studies done worldwide that demonstrate the extraordinary effects of exercise on the brain in both children and adults. His work draws on the same molecules and mechanisms scientists continue to explore today.
Factors and Peptides Provide Growth and Calm
Brain Derived Neurotrophic Factor (BDNF) acts like a nutrient for your neurons, helping them grow, connect, and communicate better. Studies show that even one workout can temporarily spike BDNF levels, while consistent training makes the effect stronger over time. A large meta-analysis found that both single workouts and long-term routines reliably boost BDNF — offering a biological explanation for why exercise helps memory, mood, and mental clarity.
ANP, or atrial natriuretic peptide, is a lesser-known heart hormone released during exercise that may help calm anxiety. Research suggests higher ANP levels are linked with lower panic and anxiety responses, hinting that aerobic workouts might soothe the nervous system from the inside out.
Exercise grows the brain, literally
The changes aren’t just chemical. Imaging studies show structural transformations in the brain, too. In one landmark trial, older adults who walked regularly increased the size of their hippocampus, a key memory and learning region, and performed better on spatial-memory tasks than those who didn’t. Because the hippocampus and prefrontal cortex govern memory, stress, and decision-making, these physical changes provide a solid foundation for improved mental health and sharper thinking.
Real-world results for mental health
Beyond lab data, clinical trials show that exercise often rivals traditional treatments for mood and attention challenges:
• Depression: In studies comparing exercise to antidepressants, both groups showed similar improvements. Meta-analyses confirm a moderate impact of physical activity on depressive symptoms.
• Anxiety: Exercise consistently lowers anxiety levels, likely through BDNF, ANP, and better stress regulation.
• ADHD: For children and adults with ADHD, regular aerobic exercise improves focus, impulse control, and overall executive function — likely thanks to increased dopamine and norepinephrine activity.
The prefrontal cortex in motion
Your brain’s “CEO,” the prefrontal cortex, manages planning, focus, and emotional regulation. Exercise promotes better blood flow, increases growth factors like BDNF, and strengthens communication networks between brain regions. Over time, this synergy translates to sharper thinking, steadier emotions, and better decision-making — a reminder that moving your body can literally help you think more clearly.
What long-term research shows
Months of consistent aerobic activity lead to measurable effects: slight increases in hippocampal volume, sustained elevations in BDNF, and lasting improvements in mood and anxiety. These benefits appear across age groups and fitness levels, even with moderate routines like brisk walking or cycling. The key is regularity, not perfection.
What we still don’t know
Some questions remain. Blood measurements of BDNF don’t perfectly reflect levels inside the brain, and individuals vary in how much exercise they need for noticeable improvements. Scientists are still studying which types and intensities of exercise best serve different mental health or cognitive goals, and how genetics and medications may influence results.
The bottom line
If you want to boost your mood, concentration, or long-term brain health, the evidence points to a simple strategy: move often and find activities you enjoy. Aim for regular aerobic exercise like walking, cycling, or swimming and add strength work when possible. Even small, consistent efforts yield real biological and psychological benefits.
Exercise isn’t magic, but it’s close. After decades of research, from brain scans to clinical trials, the picture is clear: physical activity is one of the most reliable, accessible ways to improve mental health and make your brain more adaptable. It’s a hopeful message for everyone proof that movement strengthens not just muscles, but the mind itself.
