How to Grow Your Brain with Exercise

The Theory

The brain is plastic; it isn’t fixed rigid from the day you were born to the day you will die. Brain cells can grow or die, they can strengthen or weaken throughout your life. You’ve probably heard the saying ‘when neurons fire together, they wire together.’ This is a fancy way of saying that, if you do something over and over again, you’ll get better and better at it and, eventually, you’ll be able to do that something without even thinking about it. Remember when you learnt to ride your bike? It was a nightmare at first, then you had stabilisers, then you were as free as a bird, flying down the road. That was the result of your brain’s neurons firing together over and over again and eventually wiring together so tightly that you didn’t have to think about pedalling or steering or braking any more.

Only mobile creatures need brains. Brains are very expensive things to run, they cost us a lot in terms of energy. If we didn’t really need a brain, we wouldn’t have one. There’s a particular mollusc that is born with a brain so that it can move across the rocks away from its birthplace. When it has found a new home, it doesn’t need the brain anymore so it eats it. Yum. You could say that thinking is the internalisation of movement, therefore it is only to be expected that exercise should have a profound effect on the brain.

And indeed it does. Exercise elevates the following chemicals in your brain:

  • Serotonin, which controls your mood.
  • Dopamine, which is your brain’s ‘reward centre’, linked with movement and learning.
  • Norepinephrine, which controls your attention and motivation.
  • BDNF, dubbed ‘MiracleGro for the brain’. This creates new branches of synapses. In other words: it grows brain cells.

And the more exercise you do, the more it spikes growth.

The Workout

The brain can’t learn while exercising, but blood goes to the prefrontal cortex immediately after exercise, making it ripe for learning something new.

  • Both aerobic (e.g. running, cycling) and complex activities (e.g. playing the piano, martial arts) are important.
  • Aerobic exercise elevates executive function neurotransmitters. This will create new blood vessels and new cells.
  • Complex activities increase BDNF, which strengthens and expands synapse networks. 
  • Tennis is a good example of an activity that combines both aerobic and complex activity. Other examples are yoga, pilates and dancing. Dancing to an irregular rhythm, like the tango, is particularly good for improving your brain’s plasticity.
  • Try to hit a least 35 minutes at 60-70% intensity (for women) or at your maximum heart rate (for men).


Information from this article is taken from Spark! The Revolutionary New Science of Exercise and the Brain by John J. Ratey and Eric Hagerman.

How to beat Anxiety and Fear with Exercise

The Theory

If you think about what happens when you become anxious, it is very similar to your response to hard exercise: your heart rate increases and you get out of breath. That’s stress. Because of this, exercise can become a safe place to have a high heart rate and fast breathing. You can learn that a high heart rate and fast breathing does not mean that you are having an anxiety attack. Over time you become more comfortable with arousal and your brain gets reprogrammed to deal with stressful situations without feeling anxious.

The science of it is that exercise increases levels of something called FFA in the bloodstream. As a result, this lowers the ratio of tryptophan in the bloodstream. To bring the ratio back to normal, the body increases production of tryptophan, which in turn builds serotonin, which is the chemical that makes us feel good.

Fear is the memory of anxiety

Fear is the feeling we get when we are presented with a situation that we have faced before and which made us feel anxious: it is the memory of some past anxiety. There is some truth in the saying that ignorance is bliss. Panic is the state we get into when we are paralysed by our anxiety.

Drown out the fear

You can’t erase fear completely, the synaptic pathways in your brain cannot be erased. However, you can ‘drown out’ the fear by creating new positive synaptic pathways that strengthen and become the brain’s first response to the stressful situation. Simply doing something in response to your anxiety, rather than being passive, is beneficial. This is called ‘Active Coping’.

There are a number of ways that exercise tackles anxiety:

  1. It is a distraction, literally, from the stress.
  2. It reduces muscle tension, just like beta-blockers, but unlike beta-blockers, you are totally self-reliant, which will also build your self-confidence.
  3. It builds brain resources (chemicals like serotonin, norepinephrine, GABA and BDNF), making your brain tougher.
  4. It teaches you a different outcome of a stressful situation: your heart rate is up, you’re expecting to panic – but all is good! It reroutes your negative circuits to positive ones.
  5. It improves your resilience to stressful situations. You are in control, not the anxiety.
  6. It is active, not passive, so sets you free. Locked down people get anxious and depressed.

The Workout

  • Rigorous exercise is the best way of hurting anxiety: 60-90% of your maximum heart rate.
  • It’s not just for those with anxiety disorders, exercise will help with everyday anxieties that we all face.
  • Try 3 x 90 minute workouts per week.


Information from this article is taken from Spark! The Revolutionary New Science of Exercise and the Brain by John J. Ratey and Eric Hagerman.

How to beat Stress with Exercise

The Theory

Stress is stress, the only difference is degree. There’s the extreme stress of losing your job, but even standing up from the computer is a stress on your body. The only difference is degree.

Exercise is controlled emotional and physical stress. Exercise breaks down neurons, just like any other stress, but in a controlled way. The repair mechanisms that kick in after the exercise leave you stronger for next time. A low level of stress is good for you, like a vaccine. Exercise raises your brain’s tolerance for stressful situations and you will be better able to deal with the stresses and strains of everyday life if you exercise regularly.

There’s no such thing as ‘bad’ stress

Your body makes no distinction between ‘good’ and ‘bad’ stress. Winning the lottery and being faced with a hungry lion both trigger a stress response in the brain. ‘Good’ and ‘bad’ are just our opinions and sometimes the same stress can be ‘good’ in one situation and ‘bad’ in another. For example, a soldier trained to suspect car bombs feels stress when he is faced with an unknown car: great in Afghanistan, not so useful in Amersham. Stress is what saves us when faced with the hungry lion by triggering the fight or flight response. When your brain is stressed it boosts levels of norepinephrine and dopamine, increasing your focus and attention, helping you get that essay done on deadline day!

But of course we all know that too much stress, or constant low-level stress is miserable. Stressed people become obsessed (not emotionally, chemically) with the object of the stress and ignore everything else. Stress inhibits learning as well, making the stress self-reinforcing, as your brain can’t learn from the past mistakes that have caused the stress. It becomes a negative feedback loop.

Loneliness can become a part of this negative feedback loop as well. Stress makes us less likely to seek out society and, with fewer friends, we have less support through the tough times and the stress persists.

As we all know, stress can have a serious negative impact on our health. One of the ways it does is poor diet. After stress the brain craves glucose to replenish its stocks. This is fine if we are only occasionally stressed, but if we’re constantly stressed out then this response becomes unhealthy.

How does exercise tackle stress?

  • Exercise builds more insulin receptors, for more efficient use of glucose.
  • Exercise strengthens the synaptic pathways in your brain by increasing production of BDNF. This makes your brain better able to deal with future stresses.
  • Exercise relaxes the resting tension in the muscles, so the brain can relax too.
  • Exercise lowers blood pressure.
  • Exercise can increase social activity through participation in team sports or social contact at the gym.
  • Exercise is something you can do, it gives you control over the stress. This will boost your self-confidence.

The Workout

Exercise has been shown to be more effective against stress than food, alcohol or medication so make exercise a part of your life. Consider the fact that palaeolithic man used to walk 5-10 miles a day. Today, however, a large proportion of the modern Western population (including myself) has a predominantly sedentary lifestyle. This is not the lifestyle that our brains have evolved for.

I keep exercise in my daily life by cycling around London instead of taking public transport. When I haven’t got any plans to cycle anywhere, I make sure that I take several walks during the day and try to go for a short run as well.

Team sports are particularly good ways of building exercise into your life because very often there is a constant stream of games and the obligation of not letting the team down compels you to exercise. It’s also good fun!


Information from this article is taken from Spark! The Revolutionary New Science of Exercise and the Brain by John J. Ratey and Eric Hagerman.

How to Live Longer

Eat less for a long life

It has been found that calorie restriction (i.e. eating less) in mice:

  • Extends life.
  • Prevents rapid tumour growth.
  • Makes the mice more active as well.

Anecdotally, the Okinawans of Japan, one of the world’s longest living and active populations, abide by an old saying, ‘hara hachi-bu,’ which translates roughly as ‘eat until you are 80% full.‘ Of course that is only an anecdote. In reality, they eat, on average, 11% less than the average Japanese diet.

How does that work?

It could be because, when you eat, your body produces insulin to metabolize carbohydrates and fats. Insulin also promotes growth. That means it promotes growth in malignant, i.e. cancerous, cells. Diet can change the growth environment of cells, including cancer cells. It changes the nurture, not the nature of cells. Diet does not contain carcinogens. It can just create an environment that cancer cells will flourish in.

If you restrict rats to 2/3rds of calories then they will live 30-50% longer. Why? Because they have less body fat? Because they have lower weight? No. Obese mice on a restricted diet live longer than non-obese mice on a non-restricted diet and the same as non-obese mice on a restricted diet.

Eating less is the thing, not leanness.

Why?

The popular answer is that it reduces the creation of free radical cells and therefore reduces the oxidation of cells and thus the opportunities for cancerous cells to develop. When food is scarce (i.e. when your body gets a signal that it is not eating a 100% diet) you live longer so that you will survive the starvation period and still be young enough to reproduce.

This may well be correct, but calorie restricted mice also have:

  • Low insulin resistance.
  • Low blood sugar.
  • Low insulin levels.
  • Low levels of Insulin-like Growth Factor (IGF).

Low-carb for a long life?

The glucose found in carbohydrates causes IGF and insulin levels to rise sharlply, in comparison to other food groups. So, in 2004, Cynthia Kenyon asked: could a low-carbohydrate diet lengthen lifespan in humans?
By reducing carbohydrates and glucose she was able to reduce:

  • Blood pressure.
  • Triglyceride levels (a fatty acid linked to incidence of heart disease and strokes).
  • Blood sugar levels.
  • And to increase levels of HDL (High-density lipoprotein, ‘good’ cholesterol).

While she is not able to conclude, after just six years, that a low-carbohydrate diet will lengthen the human lifespan, it seems to be promising data.


This article is based on the information found in The Diet Delusion by Gary Taubes (p218 onwards)