It’s no secret that exercise plays stress on your body, but you need this stress to force your body to change. An easy workout might feel better than an ultra-challenging, high-intensity workout that leaves you drenched but it’s unlikely to lead to substantial changes in your fitness level or your body composition. The key to making changes is to push your body harder than it’s accustomed to but do it in a controlled manner. If you overwhelm your body by placing it under too much stress in too short of a time without adequate rest and recovery, the effects of that stress accumulate and this can lead to mental and physical repercussions. We call this overreaching and, when it’s extreme, overtraining.
It was Hans Seyle who first described the General Adaptation Syndrome (GAS), the process by which the body responds to and adapts to stress. By understanding how your body reacts to the stress of training, you can better fine-tune your workouts to get optimal results without pushing your body to the point of exhaustion. You might think that pushing yourself harder and harder is the key to maximizing fitness adaptations and gain but you can actually curtail your gains if you push yourself too hard without allowing enough recovery between sessions.
Let’s look at the stages of the General Adaptation Syndrome and how they relate to fitness training:
The Alarm Stage
When you first introduce your body to a stressful stimulus, your body reacts by ringing the alarm bells. In response to the sudden stress, your body mounts a “fight or flight” response. It does this by releasing a series of hormones we call stress hormones. These include epinephrine, norepinephrine, and cortisol, hormones that prepare your body for action by increasing your heart rate, blood pressure, and by boosting blood flow to your muscles. The purpose is to help you respond to the threat with massive action! Your adrenal glands also release cortisol, a hormone that helps mobilize glucose stores to supply your muscles with energy. Once the stress is over, your heart rate slows, blood pressure drops, and your body returns to a more balanced state of homeostasis.
The Resistance Stage
The resistance stage, the second stage of adaptation, is also referred to as the adaptation stage. You enter this stage if you give your body enough recovery time after the initial, alarm stage. Once the stress is over, heart rate slows, blood pressure drops, and your body returns to a more balanced state of homeostasis. But, now that your body has experienced an alarming degree of stress, it needs to protect itself against excessive stress should it happen again. So, it undergoes adaptations that make it more resilient. Your body makes these adaptations when repeatedly exposed to stress, assuming it has enough rest between these exposures to adapt. These adaptations impact a number of bodily systems. For example, your muscle cells develop more mitochondria in response to endurance training to produce more energy aerobically and, in response to strength training, your lay down new muscle fibers so that the muscle can contract with greater force. So, the adaptations depend upon the type of exercise stress you place on it. Other systems adapt as well. Your immune system becomes more robust to help in repair and insulin sensitivity improves so that you can get more glucose into muscle cells for energy.
The Exhaustion Stage
The exhaustion stage is what you want to avoid and it only happens if you place TOO much stress on your body or don’t give it enough time to recover between applications of stress. An example would be training your muscles to failure every time you work out or not giving yourself rest days between high-intensity training sessions. If you do this repeatedly, your body enters the exhaustion stage. This is the stage we call in the fitness industry overreaching or, in more severe cases, overtraining. To reach exhaustion, your body must be pushed to the point that It can no longer adapt or recover. That’s when you begin to experience signs of pushing yourself too hard: excessive fatigue, lack of motivation, high resting heart rate in the morning, irritability, depressive symptoms, problems sleeping, and increased susceptibility to infection. You’ve pushed your body past its ability to adapt to the stress you place on it. Some athletes progress to the point that they’re so exhausted that they have to take a long break to recover.
As you can see, it’s a delicate balancing act. Some stress is good while too much overwhelms your body’s ability to adapt. So, how can you keep it in balance? The recovery time your body needs to adapt to stress and super-compensate to become more resilient varies. A younger person will need less recovery time between workouts than an older person. The amount of recovery time also varies with physical health, the degree of stress you’re experiencing in other aspects of your life, and nutritional status. At a minimum, you need 48 hours of recovery before working the same muscle group again from a strength standpoint and you should wait at least 48 hours between high-intensity workouts. However, you may need more or less time based on the factors mentioned above. The key is to listen to your body. You should feel fatigued after a workout but not exhausted and you shouldn’t feel exhausted the next day or sore all the time. These are signs that your body isn’t recovering enough between workouts.
Still, you want to place enough stress on your muscles for adaptations and super-compensation to occur. You won’t get that if you don’t challenge yourself more over time using progressive overload. You also don’t want to wait so long between training sessions that detraining takes place and you lose some of the strength and fitness you’ve already gained. It’s a balancing act and the secret is to be attuned to how you feel and respond accordingly.
The Bottom Line
Now, you know how the general adaptation syndrome relates to fitness training and why balance is so important. Adapt your workouts accordingly. A little stress is good but too much can actually interfere with your gains.