The Slightly Chubby Brigade

As the news will tell you at every single available opportunity, we are living through an obesity crisis. Across the western world (USA being the worst and Britain coming in second) our average national BMI is increasing and the number of obese and overweight people, and children especially, looks to be soaring across the board. Only the other day I saw a statistic that said nearly a third of children are now leaving primary school (ie one third of eleven year-olds) overweight, and such solemn numbers frequently make headlines.

This is a huge issue, encompassing several different issues and topics that I will attempt to consider over my next few posts (yeah, ‘nother multi-parter coming up), but for many of us it seems hideously exaggerated. I mean yes, we’ve all seen the kind of super-flabby people, the kind the news footage always cuts to when we hear some obesity health scare, the kind who are wider than they are tall and need a mobility scooter just to get around most of the time. We look at these pictures and we tut, and we might consider our own shape- but we’re basically fine, aren’t we. Sure, there’s a bit of a belly showing, but that’s normal- a good energy store and piece of insulation, in fact, and we would like to have a life beyond the weight-obsessed calorie counters that hardcore slimmers all seem to be. We don’t need to worry, do we?

Well, according to the numbers, actually we do. The average height of a Briton… actually, if you’re stumbling across this at home and you consider yourself normal, go and weigh yourself and, if you can, measure your height as well. Write those numbers down, and now continue reading. The average height of a Briton at the moment is 1.75m, or around 5’9″ in old money, and we might consider a normal weight for that height to be around 80 kilos, or 170 pounds. That might seem normal enough; a bit of a paunch, but able to get around and walk, and certainly no one would call you fat. Except perhaps your doctor, because according to the BMI chart I’ve got pulled up a 5 foot 9, 80 kilo human is deemed clinically overweight. Not by much, but you’d still weigh more than is healthy- in fact, one stat I heard a while ago puts the average Briton at this BMI. Try it with your measurements; BMI charts are freely available over the web.

This, to me, is one of the real underlying causes of ‘the obesity epidemic’- a fundamental misunderstanding of what ‘overweight’ consists of. Whenever our hideously awful everyone-dead-from-McDonalds-overdose etc. etc. diet is brought up on the news, it is always annotated by pictures of hanging bellies and bouncing flab, the kind of bodies that make one almost physically sick to look at. But, whilst these people certainly exist, there are not enough of them for the obesity issue to be even worth mentioning in everyday society; whilst the proportion of morbidly obese people is significant, it’s not seriously worth thought for most of us.

No, the real cause for all the chilling statistics we hear on the news is all the people who don’t look to be overweight. The kind whose diet isn’t appalling (no 24/7 McDonaldses), who are quite capable of exercise when it suits them, and who might take a rough glance at the dietary information of the stuff they buy in the supermarket. But these people are nonetheless hovering on the overweight borderline, pulling up the national average, despite the fact that they don’t consider anything to be wrong; in fact, some women who are according to the evil numbers overweight, may consider it almost dutiful to not become obsessed over shedding every pound and to maintain their curves. Having a bit of excess weight is, after all, still better than being underweight and anorexic, and the body image pressures some young women are coming under are just as much of an issue as national obesity. Even for those who don’t have such opinions, many of the slightly overweight feel that they don’t have any weight issues and that there’s surely no significant health risk associated with a ‘bit of meat on your bones’ (it’s actually muscle, rather than fat, that technically forms meat, but ho hum); as such, they have absolutely no motivation to get their weight down, as they don’t think they need to.

I won’t waste much of my time on all the reasons for this statement, but unfortunately even this slight degree of overweight-ness will significantly increase your risk of major health problems somewhere down the line, particularly that of heart disease (which is going through the roof at the moment); diabetes isn’t likely to be a risk for the overweight unless they’re really overdoing things, but that’s also a potential, and very serious, health hazard. The trouble is that many of us find it hard to make this connection if we basically feel healthy. Despite what the doctor says and no matter how much we trust them, if we are capable of going for a nice walk and generally getting about without getting out of breath or feeling bad then we probably feel justified in thinking of ourselves as healthy. Our heart doesn’t seem about to give out, so why worry about it.

The thing to remember is that the heart is just a muscle, so if it isn’t stressed it will degrade just like any other. You know those triceps that haven’t done a press up in five years? Feel how small and weak they are? Yeah, that kind of thing can quite easily happen to the muscles that are responsible for keeping you alive. Your heart might be pumping all day long and be a different type of muscle, so the process will be slower, but give it twenty years and you might start to see the effects.

But anyway, I’m not here to lecture you about your health; that’s far too depressing and dull for my liking- the only point I was trying to make is that many of the accidental contributors to ‘the obesity epidemic’ are probably unaware that their health is in any way a problem, and not really through fault of their own. So whose fault is it then? Well, that one can wait until next time…

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.