The General Adaptation Syndrome


The General Adaptation Syndrome

Our body is always working to maintain homeostasis. Homeostasis is our bodies internal regulator, it aims to keep all processes within the body running smoothly. Homeostasis can only keep the state of the body stable if it modifies what ‘stable’ is in response to stress and stimuli. A practical example of this is our body temperature. Most of the time our body sits at 37 degrees Celsius (give or take a little). Your body maintains homeostasis by modifying internal processes to keep your body at 37 degrees in response to the change in outdoor temperature. The ‘stress’ of a rise in temperature, enables change in your internal processes to sweat and perspire. The result? Your internal body temperature remains the same.

To further your understanding, here’s a little story about Hans Selye and how he developed the General Adaptation Syndrome Model. He subjected rats to various amounts of poison (stress) to see how they dealt with it. He found that if they give rats a large dose at the beginning of the testing, they’ll die. However, if he gave rats smaller doses and progressively increased the dosing over a period it stimulated change in their bodies and they gradually became resistant to the poison. In the end, they were able to tolerate the same dose of poison that initially killed the other rats, all because the smaller stresses allowed the body to adapt without being too much that it became fatal.

Now there is something called the Arndt-Schulz Rule:

‘For every substance, small doses stimulate, moderate doses inhibit, large doses kill.’

You might be saying, that sounds all good in theory and the rat story is interesting but how does that help me with my training?

Now would be a good time to explain the General Adaptation Syndrome (GAS). This is how our body maintains homeostasis in response to stress and stimuli. An overview of the GAS basically means this: when your body is subjected to a stress or stimuli that it hasn’t been exposed to it adapts so the next time this stress comes up, it doesn’t disturb your bodies homeostasis quite so much.

There are 3 phases to the GAS. The Shock Phase, the Adaptation Phase and the Exhaustion Phase. We want to hover between the Shock and Adaptation phase for the most efficient training. The Exhaustion Phase is when you’ve pushed too far without sufficient recovery and your body feels fatigued and possibly even sick.

The Shock Phase

The Shock Phase is the first response to training. This might be news to people but we don’t physically improve in the gym – we improve during recovery. In the first phase you hit your body with a training stimulus, your muscles get sore and your performance decreases. Ever tried running a 3km time trial as fast as you can, then following it immediately with another one? I guarantee your second time trial wasn’t as fast as your first. Why? Because you’re still in the Shock Phase, your performance has gotten worse because your body hasn’t had time to recover from what you’ve put it through. Then how does this improve my running in the future?

The Adaptation Phase

The Adaptation Phase, that’s how. After running that 3 km time trial faster than you’ve ever run it before you’re body initially goes into a state of shock (Shock Phase) but once you’re back at home relaxing, your body is working overtime to deal with this stress. You might not know it, but there’s massive biological change occurring in your body in order to maintain homeostasis. The muscular, neural, hormonal and cardio-respiratory systems are all making changes to deal with this stress better the next time around.

Basically what your body says is “I don’t like what just happened and what we had to deal with. That was uncomfortable. Let’s put the necessary changes in place so that when we deal with this again, it’s not such a shock to our system.”

This is how we improve. You put your body through a stress it hasn’t dealt with before. It in turn, aims to maintain a stable internal state (homeostasis) by improving all these different systems in your body so it can deal with it better the next time. This is how you improve your running, how you improve your back squat and how you improve your flexibility – a little bit more stress than you’ve dealt with in the past.

The Exhaustion Phase

Now for the Exhaustion Phase. The phase we don’t want to reach. If you’ve ever heard the term over-training, this is what people are referring too. You’ve exceeded what your body is capable of adapting to and it goes into a fatigued state, forcing you to slow down and it may actually make you sick.

For most people, you’ll never be ‘over-trained.’ And I prefer to think about it as under-recovery. Our body is extremely capable of dealing with the stress we place on it and unless you’re an ultra-endurance marathon runner or training hard 3 times a day, it’s unlikely you’re over-training. The issue likely comes from under-recovery.


So how do we improve our recovery? Simple. Eat better food and improve your sleep.

Sleep at least 7-9 hours a night. If you’re training extremely hard 2+ times per day than you’ll likely need 9+ hours a night. Sleep is the ultimate recovery tool and many people aren’t getting enough of it (go back and read our article on sleep for more information).

Improve your nutritional intake. What does this mean? Eat real food – if it had a face or grew from the ground – and if your goal is performance than you want to be eating enough calories to balance out your expenditure.

Other recovery modalities such as massage, foam rolling, stretching, ice baths etc. can add an extra 1% here and there but focus on the big rocks of sleep and nutrition.

Use this post in combination with yesterday’s post about progressive overload to give you a guide on improving how you train. We need to stress our bodies in a way they haven’t been stressed before in order to get better. That means doing the same 5 km run in 20 minutes every week is not going to improve your performance and your body will stop adapting. Instead aim to drop that time down to 19.50 min on the next run, followed by 19.40. This continual increase in volume, time or intensity may be uncomfortable and force you to push yourself harder than you have in the past, but that’s what it takes to improve. You might be sore or just feel sluggish after a session. That’s okay! Once we enter the Adaptation Phase and our body responds, you get better!

So make sure you’re pushing your body harder than you did the previous week and allow adequate rest in between training sessions so you don’t push into the Exhaustion Phase. If you feel run down, sick or lethargic for days in a row, it’s a good chance that you need more rest and recovery between sessions. Either decrease the volume of the session or improve your recovery.

People, athletes and coaches these days are very cautious on pushing too far in their training. And there is a fine line between working hard and plain stupidity. But when it comes to general physical preparedness, I’d rather flirt with doing too much than not enough. There’s a great quote by Theodore Roosevelt that sums this up perfectly - ‘Let us rather run the risk of wearing out than rusting out.’

Stress your body more than last time – allow sufficient recovery – adapt. #one22

#training #adaptation #GAS #generaladaptationsyndrome #progressiveoverload

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