I remember a couple of things about my first introduction to Ashtanga yoga. For a few years before that, in my early twenties, I had become rather conscious of my health. I’d lost a couple of stone in weight, I was exercising regularly and I became more aware of what I was eating. Previously, I had been a junk-food junkie, and while I wasn’t lazy (I worked hard at college) the most amount of exercise I got was walking from the halls of residence to the takeaway pizza place!

The new, healthier, streamlined version of me decided to give yoga a go. I signed up for an introductory ashtanga yoga class and, while I loved the feeling it gave me, I found it pretty hard. I liked the fact that it was hard though, so that was a positive. I was fully on board from that very first class.

One thing made me feel a bit dubious though. The teacher said to all of us who were there, without any hint that he was exaggerating, that Ashtanga yoga would change our lives. “Ok”, I thought, “that’s a big claim to make”. I’m a natural skeptic in most situations so I suppose that was always going to be my reaction.

But as it turns out he was right, for me at least. Ashtanga yoga really did change the way I live my life.

What I have found over the years is that Ashtanga yoga is a very practical system. As a skeptic, I think that is one of the things about it that appeals to me most. I like how tangible the practice is. I like that it makes you feel your body in a visceral way. I like that it forces you to become aware of what is happening right here and now.

One of the practical ways that Ashtanga yoga changes peoples’ lives is in its effect on the choices that we end up making in order to accommodate our practice.

Let’s say you have decided to go to a Mysore-style class at 6.30am on Monday morning. You are almost guaranteed not to go to the pub on Sunday evening. You also might decide that it’s better not to stay up until midnight, binge-watching Game of Thrones whilst working your way through a six-pack of cheese and onion (or “Shallot and Gouda” if you’re into the posh crisps).

Well let’s say it’s unlikely at least, but not guaranteed. You might decide to engage in those activities and go to yoga class anyway. But you will realise very quickly that you do not feel good during the class. That’s going to be pretty obvious. So next time you will be a little more likely to avoid the booze, junk-food and late nights in advance of your morning yoga practice. Again, not guaranteed, but more likely second time around. If you keep trying to do both the boozing, junk food and sleep deprivation and the yoga practice you will eventually give up one of the other.

These obviously unhealthy behaviours result in a bad practice experience of course but, as our practice becomes more established we will also start to realise that there are more subtle negative behaviours, attitudes, environments, and situations that can have a deleterious effect on our experience of yoga practice on a daily basis.

The fact that the practice feels entirely different every day (despite the series of asanas staying the same) gives us a clue as to the effect of all the other varying influences on our lives. Diet, sleep, work, relationships, and a myriad of other factors can all affect us in gross and subtle ways, both positively and negatively.

The fact that we have one constant thing in our lives – regular Ashtanga yoga practice – shines a light on the fact that it is we who are constantly changing, not the practice. And so, if we practice for a long time, without interruption, we may start to weed out the negative aspects of our lives; or at least to start to identify what has a positive effect and what has a negative effect on our bodies and minds.

We literally feel it in our bodies. The thing is, sometimes the yoga postures, breathing, bandhas, drishti feel so good that we know that it is possible to feel like that. Then, on days when it doesn’t feel so good, we start to question why. Often it’s obvious (I ate this, I drank that, I stayed up too late) and sometimes it’s more subtle, but, if we dig a little deeper, we will usually find a reason. Then it’s up to us to try to eliminate that which is causing us to suffer on our mats (and, by extension, in our daily lives).

At the end of the day, most of us practice yoga because of the way it makes us feel. And we all want to feel good while we’re actually practising. It is this desire which can, in a very practical way, lead us to start making much healthier choices in our lives.

So we let the unchanging nature of our practice act as a sort of barometer of how we are living our lives. And, as promised in my first ever yoga class, our lives will inevitably change.