• Muddy Shoes: Better That Way

    This time last year I wrote a blog about the brain benefits of regular exercise. I mentioned the idea that taking your exercise off-piste, i.e. avoiding any hard pavement or tarmac surfaces, is not just easier on the body (joints, ligaments, bones etc), but actually better for your brain. I’m going to expand on this theme here.

    If you’re jogging round the park and stick to the paths, you’re going to cross paths with many people also out exercising. Sticking to the grass, ideally by going right round the perimeter of your biggest nearby park, is likely to mean not having to come into close contact with other people who might be breathing Covid-19, flu or the common cold into the air you’re breathing. So there’s one good reason to exercise off the beaten track right there. You’ll be doing your civic duty in terms of reducing the spread of various diseases.

    By now you’re probably aware of the huge brain benefits of taking regular moderate to intense levels of cardiovascular exercise – in other words giving your heart / blood vessels plenty of work to do and getting out of breath to stretch those lung tissues. The better your heart functions, the more effectively it pumps blood to the brain. The better your lungs function, the more oxygen is added and waste gases removed as that blood passes through the brain.

    Exercise every other day and both these systems adapt to the high levels of activity so that, little-by-little, day-by-day, week-by-week, they slowly-but-surely become stronger and better coordinated when working together. That’s a reason to keep as active as possible because that way you’ll live longer and enjoy a better functioning brain. Exercise day. Rest day. Exercise day. Rest day. This kind of rhythm keeps brains happy. Not to mention the mood boosting impact of the adrenaline and endocannabinoids that are released into your bloodstream to help you keep going.

    Put exercise together with being outside and off-piste, THEN you have something even better: vestibular and cognitive training; to improve your kinaesthetic and information-handling intelligences, respectively. This is why I do a 6-10km run around Richmond Park at least once a month and have done for many years. It’s partly just the joy of being outdoors in all seasons. Usually I really feel the cold deep in my bones. I’m always the one wrapped up in more layers than anyone else; from autumn to spring. But when you’re out running you generate so much heat you always feel nice and toasty as you pick your way up hills, through woods, along the water’s edge and, in particular, after the killer climb towards the end.

    Note the puddles in the background on the right – a very slippery affair: Southwark Park 2021

    The fresh air clears out your lung holes, the exercise-triggered hormones make you feel high as a kite and the up-and-down bouncing motion even compacts all the food in your gut (helping whatever is in there to sit more comfortably; in my experience anyway). It’s almost as if our bodies were designed to do precisely that. Through millennia of careful natural selection, evolution expertly crafted our bodies and internal organs to have the capacity to run down much larger and stronger prehistorical animals. These animals were usually faster than us in a sprint, but jogging after them for hours and hours as a groups was thought to enable our ancestors to keep up until they ran out of puff making it easy to stick them with a spear. Jogging might seem a bit dull, but our bodies are very well adapted to it.

    When I say “vestibular training” – this isn’t a term you’ll find elsewhere. I use it to describe the type of workout that pushes the brain systems devoted to balance and coordination of body movements particularly hard. To picture what the vestibular system does it can be helpful to imagine yourself being thrown around on a roller-coaster. When your head (and body) fly though space on track weaving through space in three dimensions, a pair of special sensory structures inside the inner ear detect acceleration in the forwards <-> backwards and upwards <-> downwards directions. The sensory device that picks up acceleration in the upwards <-> downwards direction is called the saccule and for the forward <-> backward direction we have the utricle; both of which are a bit like a seed rattling around in a hair-lined pea pod inside your inner ear. They’re constantly broadcasting to the rest of the brain whether you are stationary or accelerating in one direction or another.

    The saccule and utricle get much more of a workout when running across open plains, meadows, hills, woods or even just muddy tracks. When there’s no path to follow, leaping across puddles and picking your way across a wooded inclines causes a lot of up and down movements as you dart around trying to make sure each footfall strikes a firm surface. When running on flat smooth surfaces, on the other hand, the information these sensory systems send to the rest of the brain is very basic, simple and straight-forward – too predictable to offer much of a challenge for the brain to integrate with the other sensory information. In other words, what I’m proposing is that our vestibular system thrives on being adventurous.

    Another part of the vestibular sensory system are the semi-circular canals (superior, posterior and lateral canals; see below). These three semi-circular fluid filled tubes are responsible for monitoring rotations of the head (and, by attachment) the body. These are the three types of rotation, each of them dealing with in terms of common head gestures: Nodding to say “yes” – that’s “pitch” rotation. Shaking your head to say “no” – that’s “yaw” rotation. (If you’re Greek, please reverse that ;-)) If you try to touch your ear to each shoulder in alternating fashion – that’s “roll” rotation. These semi-circular canals are also in the inner ear and broadcast any changes in the signal they detect to the rest of the brain too.

    The inner ear

    What does the brain do with all the info on acceleration and rotation (from saccule, utricle and semi-circular canals) as you pick your way around a puddle on the slippery canal tow path? One important role for it is as feedback on how well the brain is steering your movements. If you don’t find firm footing, and slip, the saccule / utricle will detect the unexpected changes in acceleration, and if your body has twisted in the slip this will be detected by the semi-circular canals, so the cerebellum (at the back of the head) has the information it needs to instruct various leg muscles to contract in the right order to catch our fall, in the blink of an eye. This is exceedingly good brain training. And you don’t get the same bang for your buck if you’re just doing laps of the local athletics track.

    Cerebellum (in red) hanging off the back and underside of the cortex

    This approach is not without its jeopardy. Rolled or sprained ankles can happen if you lose concentration and take you’re eye off the uneven terrain. But take it slow and easy on the more treacherous stretches and you can get away with it; even in middle age. And then there are the added challenges posed by man’s best friend.

    In any London park (and I’m sure it’s the same all over the UK) every time you step from tarmac to grass you run the risk of stepping in dog shit. Unpleasant yes, but every cloud has a silver lining. I’ve found it’s possible to harness the power of disgust to push yourself harder in terms of increasing focus and concentration. Recall how disgusting it is to realise you’ve stepped on a turd by getting a whiff of that foul stench and feelings of repulsion that come with the knowledge that you’re now bringing it with you, can be used as an incentive to become a full-on dog poo ninja.

    It may sound ridiculous, but constantly keeping a keen eye on precisely where you put each foot fall is really taxing on a variety of sensorimotor and cognitive abilities. In other words, not only do you get really good at dodging the doo doo, but you end up with abilities that are helpful in everyday life even when you’re not exercising. The kind of far transfer I’m talking about stems from the fact that doo doo dodging requires a high level of vigilance, stretching the brain pathways of attentional control to their limit, placing greater time pressure on the brain to think quickly the faster you go. You have to be ready to change direction and veer off from your chosen foothold at the drop of a hat. The concept of poo dodging might not be pleasant, but I’m convinced it speeds up your reaction times, improves your running gait and ultimately leads to a more nimble running style.

    Running on the flat encourages a very uniform gait. It becomes a matter of developing muscle density, stride cadence and boring things like that. Running on all terrains requires you to develop the brain capacities of a mountain goat: sure-footed even on uneven slopes scattered with slippery scree. The brain has to work out how to deal with all sorts of unexpected obstacles that you often don’t notice until you are right on top of them: branches to hop over, tree trunks to swerve around, streams to fjord, fern-filled valleys to scramble up and down. A richer, undulating terrain provides a greater challenge for the various brain regions receiving the vestibular sensory information to sink its proverbial teeth into.

    And then there’s the evidence – outlined in a previous blog – indicating that being outside in mother nature doing any kind of recreational activity for 2-5 hours per week has a demonstrable impact on happiness and well-being. What are you waiting for? Slip on that thermal underwear, a tracksuit and a pair of old trainers you don’t mind running through puddles in and get out there!

    In addition to these monthly brain blogs I also tweet the occasional bit of excellent brain science that I stumble on via Twitter (@drjacklewis).

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  • The Runner’s High by Dr Jack

    In previous articles on this blog I’ve described some of the many long-term brain benefits of regular exercise. These have mainly focused on the benefits that regular exercise offers to older people in terms of reducing the rate of age-related cognitive decline. But the brain benefits of taking regular exercise are applicable to everyone, young and old.

    Do It For Your Brain’s Sake

    runners-highPeople who exercise regularly have lower rates of anxiety and depression. They even boast greater cortical thickness in parts of the prefrontal cortex and the medial temporal lobe. Specifically brain scanning studies have demonstrated that the left and right hippocampus, fundamental both to creating memories and knowing where we are in space, are a little larger than in sedentary people. This increase in tissue thickness is thought to be indicative of a denser meshwork of synaptic connections reflecting a greater complexity of neuronal network. In other words several brain areas fundamentally involved in memory and cognition are able to perform better. What’s more regular exercise leads to improvements in mood and even helps you sleep better. And there is little better than a good night’s sleep for helping brains to reach peak performance.

    Exercise leads to increased levels of nerve growth factors like BDNF (brain-derived neurotrophic factors) that promote the birth and survival of new brain cells, synapses and development of new blood vessels. So this is thought to a likely mechanism for the changes in the thickness of various brain regions in people who take regular exercise and quite possible the long term benefits in cognitive ability and mental health.

    In my talks, workshops and first book (Sort Your Brain Out) I urge people to move away from thinking about exercise as a pastime motivated by the desire to improve the appearance of our bodies and more as something we should get in the habit of doing regular exercise to manage our mood / productivity in the short term and brain health in the long term. When people are feeling stressed out their motivation to hit the gym is often at rock bottom levels. A huge shame because exercise is exactly what would make them feel much, much better almost immediately.

    endocannabinoidsWhat Causes the Runner’s High?

    Athletes often talk of the “runner’s high.” This has long been explained as a result of endorphins released in the brain in response to moderate to intense exercise. It makes good theoretical sense because endorphins, the brain’s natural opiates, have the twin effect of numbing pain and making us feel good. The trouble is that up until 2008 there was little if any hard evidence to back this notion up. Yet further doubt was cast on the whole endorphin hypothesis when a study demonstrated that the runner’s high still occurred even when the effect of any released endorphins was blocked with a drug called naxalone.

    Looking elsewhere for a mechanism through which the runner’s high might be achieved researchers started to focus on a possible role for endocannabinoids. Similar in structure to the hundreds of cannabinoid chemicals found in the Cannabis sativa plant smoked recreationally in pursuit of a mood-enhancing effect, endocannabinoids are naturally produced throughout the brain.

    Subsequently, elevated endorphin levels were observed in a brain scanning study that compared brains that had recently completed a 2-hour endurance run compared to other brains that hadn’t (Boecker et al, 2008). So consensus now is that the anxiolytic effects of exercise are mediated by a combination of endocannabinoid and endorphin release in the brain.

    EndorphinsWhat Purpose Might the Runner’s High Serve?

    From an evolutionary perspective pain signals clearly should be switch on and off-able because they can be helpful or disabling depending on the context. Pain signals from damaged body parts helps us to avoid worsening the injury when at rest or engaging in gentle exercise, clearly an advantage when the priority is to allow a twisted ankle, strained knee or inflamed muscle to heal properly. But in the context of evading a predator or attempting to catch prey, such pain signals could lead to the huge potential disadvantage should it lead to getting caught and killed by the predator, or failing to catch the very food that might keep us, and our dependents, alive. The benefit of the analgesic / hedonic effect is that if a person is running to save their skin, then switching off the pain signal and inducing a light high to further compensate for any residual pain resulting in an unimpeded getaway makes perfect sense. Better to endure minor tissue damage if it is the only way to ensure you’ll live to see another day.

    runLittle and Often

    There is a huge amount of evidence to support the concept that regular exercise is extremely good for body and brain. The trouble is, we all know this but few actually get around to taking regular exercise. In my view the main reason for this is partly feeling overwhelmed by their busy lives but also probably involves exercising in the wrong way: when people do finally get around to exercising they often overdo it. Spending the whole of the next day aching all over will do little to incentivise them to take the trouble to exercising again any time soon.

    I would argue that little and often is the best policy. Even at the frantic pace of modern life everyone can fit in 20-30mins of exercise a day. That way, even if some weeks you only hit 50% of your target, you’ll still be getting your heart rate and breathing rate up, flooding the brain with highly oxygenated blood, endorphins, endocannabinoids and BDNF, 3-4 times per week – exactly the recommended dose!

    In addition to these monthly blogs you can catch my weekly podcast Geek Chic’s Weird Science (on iTunes, audioboom, libsyn, podbay) and subscribe to @drjacklewis on Twitter where I share at least three good brain news related articles every day.

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  • Gyms of the Future – Good for Body, Good for Brain by Dr Jack Lewis

    healthy brainExercise is good for health, we all know that. That said it is also clear that the whole world is utterly fixated on the benefits to the body. The considerable benefits of physical exercise for the brain are invariably overlooked. As proof of these benefits continues to trickle in and the exact mechanisms by which exercise improves brain function gradually makes itself apparent, I’m guessing we’ll find ourselves increasingly inclined to take regular exercise for our brain’s sake. This article reveals insights from a recent report I wrote about why using high tempo music can naturally stimulate the brain to help you exercise harder with a lesser perception of exertion. I also argue that we might as well further enhance this effect by distracting ourselves with on screen activities that give the brain a work out whilst we’re at it.

    lactic 1When it comes to keeping motivated in the gym, the name of the game is distraction from the discomfort caused by lactic acid building up in the muscles when the capacity of aerobic exercise is exceeded and anaerobic metabolism takes over (releasing energy without oxygen). If you are not distracted, each minute of moderately intensive exercise can seem to take an age to tick by. If, on the other hand, your mind is elsewhere, then the minutes can fly by and you can clock up a decent amount of time doing continuous exercise without really noticing the burn in your muscles so much. The bottom line is: if the brain’s attentional resources are focused intently on something in the outside world – listening to upbeat music or watching an engaging TV programme, for instance –  then it limits the amount of brain resources available for sensing what is going in inside your body. This results in a decrease in “perception of exertion” for any given workout as a direct consequence and boosts your mood (so long as it’s music that suits your personal tastes).

    CountdownI gave a talk at last year’s Fitness Industry Association annual conference in Rotherham’s amazing MAGNA Centre (ex-steel works) where I suggested that if people work out harder when their mind is elsewhere – why not go for a double whammy and actually give them some brain teasers to do to as the distraction from the pain associated with moderately intense exercise? All it would take is to have one of the screens in the cardio section of any gym displaying a series of number / word / logic puzzles.

    This vision was inspired by my own experience of playing along with Channel 4’s Countdown whilst pounding the treadmill – I completely lost track of time and clocked up a much longer-than-normal running session (for the benefit of non-UK citizens: Countdown is a British game show where a pair of contestants must create the longest word possible from a sequence of 9 randomly selected letters and a bit of mental arithmetic with randomly selected numbers). I did this three times a week and within a month I was regularly able to find words as long as those found by the on-screen contestants.

    basal_gangliaLast month, brain & fitness became the hot topic yet again when I was unexpectedly commissioned to write a report on the evidence for and against the anecdotal observation that fast tempo music seems to do something to the brain which enables people to get more out of their workout. Part of the effect boils down to plain old distraction, as discussed above. But delving deeper into the neuroscience literature revealed that whenever the brain perceives a regular beat, the basal ganglia become activated, increasing the amount of connectivity between other brain areas: those involved in creating the sound of music (auditory cortex) with those that trigger bodily movements (motor cortex).

    The basal ganglia are the brain structures that are compromised in Parkinson’s disease, which involves difficulty initiating movements, resulting in a shuffling gait and jerky limb control. So with this in mind the responsiveness of the basal ganglia to a music beat is a likely mechanism through which the sounds impact upon exercise to produce the “ergogenic” properties.

    swimming to musicThese ergogenic properties of music, particularly effective in the 162-168 bpm range, enable people to exercise faster, stronger, harder and for longer whether they are running, doing weights, cycling, circuits and even swimming. If the part of the brain involved in initiating movements (basal ganglia) is responsive to the beat, then when that beat is rapid, the muscles of the body are presumably primed to match the pace set by that beat. Creating an exercise playlist where successive tunes gradually increase the tempo should allow you to enjoy a harder work out but with a reduced perception of exertion. More gain for less pain!

    To find out the bpm of your favourite tunes I would recommend using this free, simple, but ingenious, web resource: BeatFinder. Just position your cursor over the big red button and then click along in time with the beat of the tune.

    Catch me on Twitter to hear of amazing breakthroughs in brain research every day.

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