Understanding Allostatic Load: How balance will help you perform at your best

Personal Training

Understanding Allostatic Load: How balance will help you perform at your best

By John Meeks, CSCS, Precor Master Coach, CFL1

We have all heard of homeostasis. Simply defined, it is the tendency of a system (in this case the human body) to find stability and balance. Allostasis is a term used in fitness to describe how the body responds and adapts to outside stimuli in order to achieve homeostasis. Allostatic load is the sum of all adaptive responses from all outside stimuli that cause the body to deviate from homeostasis.

Think of your brain and central nervous system like a quarterback on a football team. Homeostasis is the play that the quarterback plans to run. After looking at a change in the defence, the quarterback then calls an "audible" in order to deal with that change. Allostasis is the call and all the changes the offence makes during that audible. Whenever something causes a disruption in homeostasis inside the body, your body then kicks in different variables like hormone levels, oxygen levels, heart rate, enzymes, body temperature, etc. in order to achieve balance.

Another example is the teeter/totter. Imagine trying to balance on a teeter/totter where the fulcrum or the person opposite you is constantly moving forward and back. You would have to constantly make changes to your position in order to compensate for those movements. Allostatis is your body making those changes or adaptations to find balance.

So what causes changes in homeostasis? Stressors. Stressors can come in any number of forms. Every time we workout, we are causing some sort of stress on the body. In the same way, stress associated with relationships, money, lack of sleep, worries, or even anger at the person who just cut you off can cause a similar response in the body. The problem with the body is that it really doesn't do well in separating the stress into categories. The stress response is the process of how the body deals with all these stressors. Interestingly, the stress response is not specific: you get a similar type of response from the body whether you are running from a man-eating tiger or you just saw the blue lights pop-up in your rear view mirror as you drive down the road. A key concept with the human body is that mental stress or the perception of stress has a similar effect on your body as you attempt to lift a heavy weight.

So why is allostasis so important in your training? A key part of allostasis is that it doesn't just help you reach homeostasis after a stressor, but it also helps you adapt to future similar stressors. When your body has to generate a huge amount of force to lift weights in a workout, you put a great deal of stress on the muscles, connective tissue, nervous system, and skeletal system. Your body deals with this in two ways:

1. It uses hormones like adrenaline and cortisol to help drive energy into the working muscles to immediately deal with the demands on the body and bring it back to balance

2. After the workout it increases protein synthesis to help build bigger muscles to minimize the future stress of lifting the same weight.

Sometimes this process is good like, in the case of building muscles, but sometimes this process has a negative effect. Blood pressure is a prime example of this. Increased blood pressure is one of the most common processes for the body dealing with a stressor whether it is lifting more weight, riding the Assault AirBike, or yelling at the driver that cut you off. Increased blood pressure in a workout is important to provide key nutrients like oxygen to working muscles. However, repeated use of this response can cause some serious negative effects. Increased blood pressure can cause stress on the arterial walls which will adapt to deal with that pressure by hardening and becoming narrower. This can lead to cardiovascular disease or other health issues.

Understanding allostatic load, the adaption process, and your own body is key in finding the perfect amount of outside stimulus needed to make the changes that we are looking for, such as increased muscle mass, increased cardio-respiratory output, and better overall health. So how does this impact your approach to training?

Allostatic load includes every bit of stress that your body is taking from both a sympathetic and parasympathetic system point of view (i.e lifting weights/sleeping poorly/sickness/financial stress/ tough workout/ arguing with a partner/ worrying about children, to name a few). All of these things have an effect on your body and your ability to put maximum effort into your workout. More importantly, they limit your ability to recover and adapt for the next workout.

Allostatic load needs to be considered when training. For example, I always tell new parents that they need to change the focus of their workouts. They need to focus on stress relief, enjoying their separate time, and not focus on PRs or performance, but on the process. New parents are already bombarded with lack of sleep, increased worries, and overwhelming stress: they do not need to worry about performance or working out so hard that they get injured. This strategy can be applied to any number of stressors, including injury, work, or home life. Varying intensity through load, time frame or range of motion is a key way to lower the stress associated with workouts to an appropriate level based on the individual's situation.

Your body is limited in the amount of resources it has to commit to adaptation. Continually overloading it just weakens its ability to recover and marginalises its ability to do anything well. Keep in mind, training is about providing the correct amount of stimulus that provides the maximum amount of adaptation in the body to help you reach your goals. Sometimes more is not better, but actually moves you the other way in the spectrum since your body can only deal with so much adaptation at any one time.

Don't get me wrong: you have to train hard to make that change in your body. This is even more important as you get stronger and more athletic because your body becomes desensitised to the stimulus and reacts less to it. However, you also need to find balance in your life. Sleep well, vary the intensity of your training, meditate, let the anger go towards the person that cuts you off in traffic. When a lifting session goes bad, remember that the journey is a winding and hilly one, and that intelligent training decisions today make you stronger tomorrow.

Enjoy life, shrug off stressors and laugh often. It's not only good for your soul, but it's also good for your training!


  1. McEwen, Bruce and Teresa Seeman. Allostatic Load and Allostasis. August, 2009. http://www.macses.ucsf.edu/research/allostatic/allostatic.php.
  2. Viada, Alex. The Hybrid Athlete. Ebook: Pp. 24-48, 2015.

Author Information

John Meeks
John Meeks's picture

John has over 20 years experience in the fitness industry.  He has worked for 10 years as a strength and conditioning coach with multiple youth athletic teams and clubs and has assisted with over 50 athletes attending Division 1 schools. He is the head coach and co-owner of 2 CrossFit gyms in North Carolina, and is a Precor Master Coach. He is also the Director of the War of the WODS - one of the largest CrossFit competitions on the East Coast with over 1200 competitors.    

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