top of page
  • Writer's pictureBodyjunkies

What Happens to Your Body During a Work-Out?

Exercise - for some, it can be a bit of an addiction, but luckily, it’s an addiction to being healthy and keeping fit! How many people who regularly exercise know what is going on in their body as they get active? From your muscles to the brain and internal organs, when you’re working out, everything is affected, whether it’s working harder or slowing down to let other processes take priority.

These processes happen every time you exercise, from beginners to established professionals, whether you work out at home or take it to the gym, exercising alone or as part of a class. If you are looking for classes at a gym, in or around Islington, London, we’ve included our details at the bottom of this post.

Exercise can, of course, target different areas and muscle groups and there is a wide range of different workouts you can take part in from cardio to strength training. We discuss a brief outline of what happens to the body during lengthy exercises like running and riding a bicycle.

First Ten Minutes of Exercise

As you start to exercise, your internal systems begin to release signals to different parts of your body, telling them to react differently. Your digestive system slows down so priority can be passed to your heart and lungs and your pupils dilate, increasing the amount of available glucose in your blood for energy.

You will also feel your heart rate begin to increase. This occurs as the adenosine triphosphate (ATP) – another energy-storing chemical in the body - and glucose get used up. As your body now needs to make more ATP, you require more oxygen and your breathing quickens to increase oxygen in the blood. Your heart now works harder to pump this newly oxygenated blood around your muscles.

The first 10 minutes of exercise is the hardest for most, as the body works to move from rest to workout mode. As the body moves into workout mode, with blood pumping around the system, you have cleared the first hurdle of your workout and are ready to up the intensity.

During Exercise

As you continue with your exercise, you may notice that your skin feels hot to the touch. Your body heats up from activity and needs to cool, so blood vessels under the skin dilate to increase blood flow. The generated heat then dissipates from your dilated blood vessels and through your skin, making you feel cooler.

A similar thing happens as you sweat. Your body produces an (odourless) perspiration, which evaporates from your skin, lowering your body temperature.

At this point (depending on your fitness levels) you may have noticed or started to notice soreness in your muscles. Soreness presents as tiny, micro-tears occur in your muscle. This is completely natural and, in fact, as these tears repair themselves, this is how muscle builds strength. As the famous saying goes, ‘no pain, no gain’.

After 20 minutes of exercise, your brain has moved into the “feel good” zone and is releasing all sorts of happy hormones known as endorphins. You will also feel more awake, alert and focused at this point due to the increased blood flow to your brain. If you are exercising at a constant rate – such as training for a marathon – this is the area that you will want to stay in as you rattle off the miles.

If you take part in any of our B-HIIT exercise classes in Islington, your body will be challenged with high-intensity cardio mixed in with targeted strength training - making sure you can't just coast along at any point during the session!

How Endorphins Work on the Body

Ask anyone who regularly exercises and they will be quick to tell you that endorphins lift your mood as they are released. While this is true, endorphins also work to reduce your pain IQ – this means that the amount of pain that you register is lowered by the introduction of endorphins. As well as through exercise, endorphins are also commonly released through stress and pain.

Endorphins work similarly on the body to morphine and codeine, reducing the effects of pain and stress – thus resulting in the more positive frame of mind. Those who regularly attend our Islington exercises classes experience the euphoric state and release of endorphins that a challenging workout provides.

After Exercise

After you finish an exercise, your body will return to its resting state, although depending on your fitness levels, this could take a little time. The fitter you are, the quicker your heart rate will drop to its resting state. Eventually, your heart rate will begin to fall, your breathing will slow, your blood pressure drops and your other processes (like digestion) come out of standby and return to a normal rhythm.

If you do not exercise regularly, after a workout you will likely feel the muscles in your body tightening, especially if you have not worked those muscles for a few weeks or more. Muscles can feel stiff and uncomfortable – this comes from the introduction of lactic acid. During exercise, oxygen is used to break down glucose and turn it into energy to keep the body going. An intense workout might mean that there is simply not enough oxygen in the system, so the body produces a substance known as lactate. This can build up in the bloodstream much more quickly than it can be burned off.

It’s quite interesting to see how our body copes with some of the stresses we can put it under, considering humans evolved from an ancestor designed to walk rather than run long distances. As we push ourselves to the absolute limits that our bodies are capable of, the next generation matches end exceeds the bar that was raised.

If you are looking to get fit or are a fitness addict looking to join some classes and try somewhere new, come and check out the Bodyjunkies studio gym near Islington, London. You can find us on Holloway Road or get in touch if you’d like more information on our exercise classes.


489 views0 comments

Recent Posts

See All


bottom of page