What Actually Happens During Exercise?

What Happens When We Exercise?

So, we all know how important regular exercise is to living a longer, happier and healthier life (even if it we don’t quite manage to be as active every day as we would like.)  

What we sometimes don’t give as much thought too, is why. Why is it so important to be seeking out and securing these opportunities for regular movement?  What exactly is going on under the surface?

Why Is The ‘Why’ Important?

‍

When you know ‘why’ something works, it increases your likelihood of embracing it - and also makes you more informed, which makes you better suited to making decisions in line with whatever you’re trying to achieve.

‍

Exercise and physical activity can lead to numerous physical (physiological) and mental (psychological) health benefits. We didn’t want to make this a really long and complicated blog post, because, well no one wants to be here reading this all day.

So to start things off on our quest for uncovering the science behind fitness, we’ve honed in on the powerhouse crucial to all exercise and activity;

‍

The Cardio-Respiratory System.

AKA the heart and the lungs.

The main task here is to deliver blood to the body’s organs and tissues, so that they receive the oxygen and nutrients they need.

When we exercise the metabolic needs of our muscles change – they need more oxygen and they need it NOW. They also start to produce metabolic waste (things like carbon dioxide and lactic acid) which need removing.

When we are resting (or sitting at our desks working ) our bodies are pumping around five litres of blood in a constant cycle from the heart to the lungs and back (to collect in oxygen and deliver back carbon dioxide) and to all the body tissues and back (to deliver oxygen and nutrients and collect carbon dioxide.)

It’s basically your very own internal courier system collecting parcels from the depot, delivering them at people’s doors and then bringing any failed ones back to depot again. (Insert favourite courier company of choice/complaints about online shopping parcels never arriving, or is that just me)

‍

Anyway, when we exercise, our clever hearts can increase pumping capacity from around 2 fold (say, with a moderate walk around the block) to up to almost seven-fold (in outrageous feats by elite athletes)….that’s up to 5 litres of blood every 9 seconds.

‍

Crazy! But very necessary - as our hard working muscles that are doing the exercise need the oxygen.

‍

Why Do Muscles Need Oxygen During Exercise?

We have over 600 muscles. And when we exercise, generally we are striving to boost muscles size, strength and endurance.

When we perform exercise - our muscles undergo a growth process called hypertrophy. This occurs because exercise causes tiny tears in the muscle fibres, and as the body repairs and heals these tears, the muscle fibres become thicker and stronger. #gains

This is why sometimes it feels like you can’t sit down after a heavy workout. Body pump is famous for producing this response, because of the classic mistake of underestimating how long the tracks are and picking too heavy a weight…..so we’re told.

So, as we mentioned earlier - when we exercise, our bodies require more oxygen and energy to spur us to move.

The muscles undergo a metabolic change - breaking down glucose (made from glycogen, the carbohydrate the body has stored, derived from the foods we eat) to provide energy.

It also uses something called adenosine triphosphate (ATP) which is the sole fuel for muscle contraction, but we won’t go into that now because we genuinely want you to read to the end of this blog.

After using up the bodies small supply of reserve glycogen stores, more oxygen is required to create more ATP, to aid movement. Ok so we need more oxygen, we get it. Now what happens?

Shifting Focus To The Lungs

Did you know (because we didn’t) that under normal conditions we are on average inhaling and exhaling about half a litre of air per breath (about six litres of air every minute.) And just like the heart can increase capacity to cope with the demands of exercise, so can the lungs – up to 30 times!

For most of us, it jumps up to shifting around 3 litres per breath. We start to breath faster and heavier, to desperately supply more oxygen into the body. This happens in the alveoli (air sacs in the lungs used to extract oxygen from air) and then once the blood cells are oxygenated they make their way to the heart…

Over To You, Heart

‍

Our heart rate increases to pump more of our oxygenated blood quickly round to our organs including muscles. The more you exercise, the more efficient the heart becomes at doing this - practise makes perfect!­ - so you can work out longer and harder. Winning.

The oxygenated blood travels around delivering the oxygen and collects excess carbon dioxide.These de-oxygenated cells return to the lungs ready for the carbon dioxide to be breathed out, and fresh new oxygen to arrive. The cycle starts all over again.

At this point during exercise we’re probably red faced, sweaty and wanting to give up – but just remember, this is where the magic is happening. Regular exercise increases the efficiency and strength of the heart and lungs due to constantly performing these processes again and again, over and over. It simultaneously also improves circulation and lower blood pressure.

‍

So however hard it may seem - be it walking a mile, running a 10k, taking a gym class - stay consistent, stick with it and you will look back in a week, a month, a year and be amazed at what you have become capable of and achieved along the way.

There are so many other benefits to constant exercise (e.g. effect on brain health, mental-wellbeing, bone health, skin.) Stay tuned for more attempts to break down the processes behind these shortly.

‍