The Science of Iron

I have mentioned before that I am something of a casual gymgoer- it’s only a relatively recent hobby, and only in the last couple of months have I given any serious thought and research to my regime (in which time I have also come to realise that some my advice in previous posts was either lacking in detail or partially wrong- sorry, it’s still basically useful). However, whilst the internet is, as could be reasonably expected, inundated with advice about training programs, tips on technique & exercises to work different muscle groups (often wildly disagreeing with one another), there is very little available information concerning the basic science behind building muscle- it’s just not something the average gymgoer knows. Since I am fond of a little research now and then, I thought I might attempt an explanation of some of the basic biology involved.

DISCLAIMER: I am not a biologist, and am getting this information via the internet and a bit of ad libbing, so don’t take this as anything more than a basic guideline

Everything in your body is made up of tiny, individual cells, each a small sac consisting of a complex (and surprisingly ‘intelligent’) membrane, a nucleus to act as its ‘brain’ (although no-one is entirely sure exactly how they work) and a lot of watery, chemical-y stuff called cytoplasm squelching about and reacting with things. It follows from this that to increase the size of an organ or tissue requires these cells to do one of two things; increase in number (hyperplasia) or in size (hypertrophy). The former case is mainly associated with growths such as neoplasia (tumours), and has only been shown to have an impact on muscles in response to the injection of growth hormones, so when we’re talking about strength, fitness and muscle building we’re really interested in going for hypertrophy.

Hypertrophy itself is still a fairly broad term biologically, and only two aspects of it are interesting from an exercise point of view; muscular and ventricular hypertrophy. As the respective names suggest, the former case relates to the size of cells in skeletal muscle increasing, whilst the latter is concerned with the increase in size & strength of the muscles making up the walls of the heart (the largest chambers of which are called the ventricles). Both are part of the body’s long-term response to exercise, and for both the basic principle is the same- but before I get onto that, a quick overview of exactly how muscles work may be in order.

A muscle cell (or muscle fibre) is on of the largest in the body, vaguely tubular in shape and consisting in part of many smaller structures known as myofibrils (or muscle fibrils). Muscle cells are also unusual in that they contain multiple cell nuclei, as a response to their size & complex function, and instead of cytoplasm contain another liquid called sarcoplasm (more densely packed with glycogen fuel and proteins to bind oxygen, and thus enabling the muscles to respire more quickly & efficiently in response to sudden & severe demand). These myofibrils consist of multiple sections called myofilaments, (themselves made of a family of proteins called myosins) joined end-to-end as repeating units known as sarcomeres. This structure is only present in skeletal, rather than smooth muscle cells (giving the latter a more regular, smoothly connected structure when viewed under the microscope, hence the name) and are responsible for the increased strength available to skeletal muscles. When a muscle fibril receives an electrical impulse from the brain or spinal cord, certain areas or ‘bands’ making up the sarcomeres shrink in size, causing the muscle as a whole to contract. When the impulse is removed, the muscle relaxes; but it cannot extend itself, so another muscle working with it in what is known as an antagonistic pair will have to pull back on it to return it to its original position.

Now, when that process is repeated a lot in a small time frame, or when a large load is placed on the muscle fibre, the fibrils can become damaged. If they are actually torn then a pulled muscle results, but if the damage is (relatively) minor then the body can repair it by shipping in more amino acids (the building blocks of the proteins that make up our bodies) and fuel (glycogen and, most importantly, oxygen). However, to try and safeguard against any future such event causing damage the body does its bit to overcompensate on its repairs, rebuilding the protein structures a little more strongly and overcompensating for the lost fuel in the sarcoplasm. This is the basic principle of muscular hypertrophy; the body’s repair systems overcompensating for minor damage.

There are yet more subdivisions to consider, for there are two main types of muscular hypertrophy. The first is myofibrillated hypertrophy, concerning the rebuilding of the myofibrils with more proteins so they are stronger and able to pull against larger loads. This enables the muscle to lift larger weights & makes one stronger, and is the prominent result of doing few repetitions of a high load, since this causes the most damage to the myofibrils themselves. The other type is sarcoplasmic hypertrophy, concerning the packing of more sarcoplasm into the muscle cell to better supply the muscle with fuel & oxygen. This helps the muscle deal better with exercise and builds a greater degree of muscular endurance, and also increases the size of the muscle, as the increased liquid in it causes it to swell in volume. It is best achieved by doing more repetitions on a lower load, since this longer-term exercise puts more strain on the ability of the sarcoplasm to supply oxygen. It is also advisable to do fewer sets (but do them properly) of this type of training since it is more tiring; muscles get tired and hurt due to the buildup of lactic acid in them caused by an insufficient supply of oxygen requiring them to respire anaerobically. This is why more training on a lower weight feels like harder work, but is actually going to be less beneficial if you are aiming to build muscular strength.

Ventricular (or cardiac) hypertrophy combines both of these effects in a response to the increased load placed on the muscles in the heart from regular exercise. It causes the walls of the ventricles to thicken as a result of sarcoplasmic hypertrophy, and also makes them stronger so that the heart has to beat less often (but more powerfully) to supply blood to the body. In elite athletes, this has another effect; in response to exercise the heart’s response is not so much to beat more frequently, but to do so more strongly, swelling more in size as it pumps to send more blood around the body with each beat. Athletic heart syndrome, where the slowing of the pulse and swelling of heart size are especially magnified, can even be mistaken for severe heart disease by an ill-informed doctor.

So… yeah, that’s how muscle builds (I apologise, by the way, for my heinous overuse of the word ‘since’ in the above explanation). I should point out quickly that this is not a fast process; each successive rebuilding of the muscle only increases the strength of that muscle by a small amount, even for serious weight training, and the body’s natural tendency to let a muscle degrade over time if it is not well-used means that hard work must constantly be put in to maintain the effect of increased muscular size, strength and endurance. But then again, I suppose that’s partly what we like about the gym; the knowledge that we have earned our strength, and that our willingness to put in the hard work is what is setting us apart from those sitting on the sofa watching TV. If that doesn’t sound too massively arrogant.

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Why we made the bid in the first place

…and now we arrive at the slack time, that couple of weeks between the end of the Olympics and start of the Paralympics where everyone gets a chance to relax, wind down a little, and take time away from being as resolutely enthusiastic and patriotic as we have been required to for the last two weeks (or a lot longer if you factor in the Royal Wedding and Queen’s Jubilee). However, it’s also an undoubtedly good time to reflect on what have been, whatever your viewpoint, a very eventful last couple of weeks.

To my mind, and certainly to those of the Olympic organisers, these games have been a success. Whether you feel that it was all a colossal waste of money (although how anyone can think that of an event featuring the Queen parachuting out of a helicopter alongside James Bond is somewhat puzzling to me), or the single most amazing thing to grace the earth this side of its existence (in which case you could probably do with a nice lie down at the very least), its motto has been to ‘Inspire a Generation’. From a purely numerical perspective, it appears to have worked- sports clubs of all sorts up and down the land, even in niche areas such as handball, have been inundated with requests from enthusiastic youngsters after membership, and every other sentence among BBC pundits at the moment appears to include the phrase ‘the next Mo Farah/Usain Bolt/Ben Ainslie/Chris Hoy’ (delete as applicable).

However, I think that in this respect they are missing the point slightly, but to explain what I mean I’m going to have to go on a bit of a tangent. Trust me, it’ll make sense by the end.

So…, what is the point of sport? This has always been a tricky one to answer, the kind of question posed by the kind of awkward people who are likely to soon find an answer flying swiftly towards them in foot-shaped form. In fact, I have yet to hear a convincing argument as to exactly why we watch sport, apart from that it is for some unexplained reason compelling to do so. But even if we stick to the act of participation, why do we bother?

Academics and non-sportspeople have always had a whole host of reasons why not, ever since the days that they were the skinny, speccy one last to be picked in the dreaded playground football lineup (I’ve been there- not fun). Humans are naturally lazy (an evolutionary side-effect of using our brains rather than brawn to get ahead), and the idea of running around a wet, muddy field expending a lot of precious energy for no immediately obvious reason is obviously unappealing. Then we consider that the gain of sport, the extent to which it contributes to making the world a better place is, in material terms at least, apparently quite small. Humankind’s sporting endeavours use up a lot of material for equipment, burn a lot of precious calories that could be used elsewhere around the world to help the starving, and often demand truly vast expenses in terms of facilities and, in the professional world, salaries. Even this economic consideration does not take into account the loss in income presented by the using up of acres upon acres of valuable land for sports facilities and pitches. Sport also increases the danger factor of our lives, with a heavy risk of injury ranging from minor knocks to severe, debilitating disabilities (such as spinal injury), all of which only adds to the strain on health services worldwide and further increases the ‘cost’ of sport to the world.

So why do we bother with it at all? Why is it that the question governments are asking themselves is “why aren’t enough kids playing sport?” rather than ‘why are so many of them doing so’? Simple reason is that, from every analytical perspective, the benefits of sport far outweigh the costs. 10% of the NHS’ entire budget is spent on dealing with diabetes, just one of a host of health problems associated with obesity, and if just half of these cases were to disappear thanks to a healthier lifestyle it would free up around an extra £5 billion- by 2035, diabetes could be costing the country around £17 billion unless something changes. Then there are the physical benefits of sport, the stuff it enables us to do. In the modern world being able to run a kilometre and a half in four minutes might seem like a pointless skill, but when you’re being chased down the street by a potential mugger (bad example I know, but it’ll do) then you’d definitely rather be a fit, athletic runner than slow, lumbering and overweight. Sport is also one of the largest commercial industries on earth, if not on a professional level then at least in terms of manufacture and sale of equipment and such, worth billions worldwide each year and providing many thousands or even millions of jobs (although some of the manufacturing does admittedly have a dubious human rights record). The health benefits of sport go far beyond the physical & economic too, as both the endorphins released during physical activity and the benefits of a healthy lifestyle are known to increase happiness & general well-being, surely the ultimate goals of all our lives. But perhaps most valuable of all is the social side of sport. Whilst some sports (or, more specifically, some of the &%^$£*)@s involved) have a reputation for being exclusive and for demoralising hopeful youngsters, sport when done properly is a powerful force for social interaction & making friends, as well as being a great social equaliser. As old Etonian, heir his father’s baronet and Olympic 110m hurdles finalist Lawrence Clarke recently pointed out in an interview ‘On the track it doesn’t matter how rich your family is or where you’ve come from or where you went to school; all that matters is how fast you can get to the finish line’ (I’m paraphrasing, but that was the general gist). Over the years, sport has allowed mixing between people of a myriad of different genders and nationalities, allowing messages of goodwill to spread between them and changing the world’s social and political landscape immeasurably. This Olympics was, for example, the first in which Palestinian and Saudi Arabian women competed, potentially paving the way for increased gender equality in these two countries.

Clearly, when we all get behind it, sport has the power to be an immense tool for good. But notice that nowhere in that argument was any mention made of being the physical best, being on top of the world, breaking world records because, try as one might, the value of such achievement is solely that of entertainment and the odd moment of inspiration. Valuable though those two things surely are, they cannot begin to compare with the incalculable benefits of a population, a country, a world united by sport for the good of us all. So, in many respects, the success of an Olympic games should not be judged by whether it inspires a new superstar, but rather by how it encourages the guy who turns up with him at that first training session, who might never be that good a competitor… but who carries on turning up anyway. The aim of top-flight sport should not be to inspire the best. It should simply be to inspire the average.